Special Colloquium
Silvia Leurini	ORATED

MPIfR Bonn

In this talk, I will present a detailed analysis of the diagnostic properties of methanol (CH3OH) in dense molecular clouds, made possible by the availability of new (CH3OH-He) collisional rate coefficients. Using a spherical Large Velocity Gradient (LVG) model, the dependence on kinetic temperature and spatial density of various millimeter and submillimeter line bands is investigated over a range of physical parameters typical of high- and low-mass star-forming regions. I will also describe an innovative technique to handle the problem of deriving physical parameters from observed multi-line spectra of a molecule, based on the simultaneous fit of all the lines with a synthetic spectrum, finding the best physical parameters using numerical methods. Application to a sample of 13 high mass star forming regions, observed in single dish, will be presented. I will also discuss the results obtained by the analysis on methanol high resolution data towards the high mass protostellar object IRAS 05358+3543, obtained with the Plateau de Bure Interferometer.

	Main Colloquium
Dr. Sergey Sazonov	ORATED

MPA, Garching

The gamma-ray burst discovered by INTEGRAL on 3 December 2003 and later associated with a core-collapse supernovae has attracted a lot of attention because its isotropically equivalent gamma-ray energy output was 3 orders of magnitude lower than is typical for GRBs, while its temporal and spectral properties were not unusual. Also the afterglow of GRB 031203 was underenergetic. This combination of properties makes GRB 031203 similar to GRB 980425, which was previously considered by many a peculiar event. Since both GRB 031203 (at z=0.0085) and GRB 980425 (z=0.106) are nearby events, we conclude that they likely represent a numerous population of intrinsically sub-energetic GRBs that previously escaped our attention merely due to their faint prompt and afterglow emission.

	Special Colloquium
Dr. Torsten Enßlin	ORATED

MPA Garching

(Computerdemonstration und Diskussion) Der Planck Prozesscoordinator (ProC) ist eine Steuerungssoftware zum Ausfuehren von Softwarepipelines (oder Workflows) zur Datenverarbeitung. Er wird fuer die PLANCK-Mission entwickelt, ist aber generisch angelegt, um auch in anderen Projekten die Datenprozessierung zu steuern. Pipelines werden grafisch erstellt und bestehen aus Programmen in verschiedenen Programmiersprachen (F,C,C++), Datenfluessen und Kontrollelementen (Schleifen, Aufspaltungen, Entscheidungen, ...). Die Datenfluesse aus und in die Anwendungsprogramme koennen durch ein Data Management Component (DMC) transparent an ein Datenbanksystem angeschlossen werden. Der ProC protokolliert die Ausfuehrung von Pipelines und versieht alle Datenobjekte mit Referenzen zu der sie erzeugenden Pipeline. Dies ermoeglicht eine spaetere Rekonstruktion der Entstehungs- geschichte jedes Datenobjektes.

	Special Colloquium
Dipl.-Phys. Ole Marggraf	ORATED

Sternwarte Bonn

TBA

	Special Colloquium
Dr. Thomas A. Oosterloo	ORATED

ASTRON (Netherlands)

I will discuss deep HI observations of a small number of nearby spiral galaxies recently done with the WSRT, the VLA and the ATCA. The observations show that these galaxies have significant amounts of neutral hydrogen in their halos. Up to 10found in the halo. While most of the halo HI is in a disk a few kpc thick, it can reach heights above the disk of up to 15 kpc. The overall kinematics of most of the halo HI is regular. The rotation of the halo HI is 20-50 km/s lower than that of the HI in the galaxy disk, while it also shows a small radial inward motion of about 15 km/s. Locally, large vertical motions of more than 200 km/s are observed. The most likely explanation for these HI halos is that they correspond to the cooling, inflow phase of galactic fountains that are driven by star formation in the disk. Apart from the halo HI related to star formation, large HI complexes of 107 Msol or more are detected in the halo of a number of galaxies. They may be extragalactic analogues of the larger HVC complexes seen in our galaxy. They are most likely remnants of small companions accreted by the main galaxy.

	Informal Colloquium
Dr. Fabrice Herpin	ORATED

Observatoire de Bordeaux

Knowledge about the outermost portions of galaxies is limited owing to the small amount of light coming from them. It is known that in many cases HI extends well beyond the optical radius. In the centres of galaxies, however, H2 usually dominates by a large factor, raising the question of whether H2 is also abundant in the outer regions. Here we report the detection of emission from CO, the most abundant tracer of H2, beyond the optical radius of the nearby galaxy NGC4414. We conclude that although molecular clouds can form in the outer region of this galaxy, there is little mass asssociated with them.

	Special Colloquium
Tim Huege	ORATED

MPIfR Bonn

High-energy cosmic rays initiate extensive showers of relavistic particles traversing the atmosphere. These air showers have been known for almost 40 years to emit pulsed radio emission at frequencies around 50 MHz. The nature of the underlying emission mechanism has, however, so far been rather uncertain. With the advent of fully digital radio interferometers such as LOFAR, radio measurements can be used as an efficient observing technique in cosmic ray research, requiring a detailed model of the emission process. In this talk, I present modelling efforts in the scheme of “coherent geosynchrotron radiation” from electron-positron pairs gyrating in the earth’s magnetic field. I will demonstrate how the model has been developed and verified , and show that it successfully reproduces the available historical experimental data. I present predicted dependences of the radio emission on specific air shower parameters, providing a solid basis for the interpretation of future experimental data, and demonstrate that the predicted polarisation characteristics of the emission can be used for a direct verification of the geomagnetic origin of the emission.

	Informal Colloquium
Dr. Sylvain Bontemps	ORATED

Observatoire de Bordeaux

A rich and massive molecular complex is presently forming OB stars in the region often refered as Cygnus X. The present star formation activity is essentially associated with the Cygnus OB2 young cluster which is situated at 1.7 kpc from Sun. Imaging surveys from infrared to millimeter wavelengths provide us with the opportunity of a complete review for massive protostars in a single molecular complex. We will present this overview in order to discuss in an unbiased way the typical properties of the earliest phases for OB star formation. It is for instance found that a significant population of IR-quiet massive protostars exists. These “cold” protostars appear to coincide with the very early but already collapsing/accreting phase of the OB star formation.

	Main Colloquium
Dr. Werner Becker	ORATED

MPE Garching

X-ray and optical astronomy has made great strides in the past several years thanks to telescopes with larger effective areas and greatly improved spatial, temporal and spectral resolutions. The next generation instruments like XEUS and Constellation-X in the X-rays, GLAST in the Gamma-ray band and the James Webb Space Telescope and the ESO 100m Telescope in the optical/UV are supposed to bring again a major improvement in sensitivity making this observatories challenging especially for pulsar and neutron star astronomy. The purpose of the talk is to review the properties of the next generation of optical, X-ray and Gamma-ray telescopes which are proposed to become operational in the next 5-25 years.

	Informal Colloquium
Dr. Joerg Fischera	ORATED

Mt Stromlo Observatory, Australia

The light of galaxies, in particular at UV-wavelengths, is attenuated by the dust in the diffuse interstellar medium. To obtain information about the intrinsic parameters as the star-formation rate a correction due to this effect can be important. But due to the lack of a physical model this correction in particular at high red-shifts is unfortunately quite uncertain. A possible solution lies in a realistic description of the very in-homogeneous structure of the interstellar medium which is likely caused by its turbulent motion. I will show how an idealised model of the structure of the local density in an isothermal turbulent medium can be constructed which might be useful to understand the radiative transport through such a medium. It will be discussed how the statistical properties of the turbulent medium affect the dust attenuation of a non scattering medium assuming different simple geometries for the distribution of stars and dust.

	Informal Colloquium
Dr. Andrew Walsh	ORATED

Department of Physics and Astronomy, Curtin University, Perth

We have observed N2H+ and HCO+ in the clustered 2 star forming region NGC 1333 using BIMA and FCRAO. Our observations cover a wide area (14’ x 14’) with a high angular resolution (7arcsec). The region exhibits filamentary structures, outflows and infall signatures. Whilst HCO+ clearly traces outflows in the region, N2H+ closely follows dust continuum emission. We identify approximately 200 HCO+ and over 100 N2H+ cores within the region with masses ranging from 1 Msun down to 0.05 Msun. A significant proportion of the N2H+ cores appear to be bound, based on their virial masses. N2H+ cores have a median line width of 0.27 km/s, median size of 0.014 pc and median LTE mass of 0.32 Msun.

	Main Colloquium
Dr. Jim Hinton	ORATED

MPI, Heidelberg

H.E.S.S. is an array of imaging Cherenkov telescopes designed for high sensitivity measurements of astrophysical gamma ray sources in the 100 GeV to 10 TeV regime. Its southern hemisphere location (in the Khomas Highlands of Namibia) makes it an ideal instrument for the study of the complex region close to the centre of our galaxy. Observations of the galactic centre region have been made with H.E.S.S.during 2003 (with two telescopes) and 2004 (with the full four telescope array). The unprecedented angular resolution and pointing precision of H.E.S.S. have allowed us to make the most precise measurements so far of the very high energy signal from the galactic centre.

	Special Colloquium
Prof. Wlodzimierz Bednarek	ORATED

University of Lodz, Poland

TBA

	Informal Colloquium
Agnieszka Sierpowska	ORATED

University of Lodz, Poland

TBA

	Special Colloquium
Philip Willemsen	ORATED

Uni-Bonn

The huge amounts of (spectro-)photometric data foreseen to come from astrometric satellites can only be handled properly with automated procedures. Tests with such procedures (NN, SVM, MDM) to determine the astrophysical parameters of the objects detected demonstrate the potential of the automated approach. Applications to simulated data and to currently available VLT spectra will be presented.

	Main Colloquium
Dr. Carlos de Breuck	ORATED

European Southern Observatory, Garching bei München

Powerful radio galaxies are the most luminous galaxies known in K-band out to z=5.2. I will introduce a Spitzer program aimed at showing that these galaxies are also the most massive galaxies known at every redshift, with baryonic masses of  1012 MSun. Using 8-band mid-IR imaging and supporting optical + near-IR photometry and optical polarimetry, we shall disentangle the stellar light from the direct and scattered contributions from the AGN and from the narrow-line regions. Next, I shall present multi-wavelength observations of one of the most distant proto-clusters known to date, surrounding a z=4.1 radio galaxy. MAMBO 1.2mm imaging has uncovered an overdensity of mm sources, which have not been seen at optical wavelengths. If they are part of the proto-cluster, they may be responsible for the majority of the star formation. Finally, I shall discuss the thermal dust and CO emission in high redshift radio galaxies. A survey of >70 radio galaxies shows a clear increase in the FIR luminosity at z>3, indicating a higher star formation rate at high redshift. At least 2 of the 6 CO detections to date appear to consist of two compact gas-rich sources, as often seen in more nearby ULIRGs and distant (sub)mm galaxies. Combined, these results suggest that radio galaxies may well be associated with massive radio-loud counterparts of (sub)mm galaxies.

	Special Colloquium
Prof. Dr. Sami K. Solanki	ORATED

Max-Planck-Institut fuer Sonnensystemforschung, Katlenburg-Lindau

The magnetic field is the driving force behind the constant unrest that modern instruments have revealed on and above the Sun’s surface. The Sun’s magnetic field is responsible for producing phenomena as diverse as dark sunspots, graceful prominences and loops or violent eruptions. There is no doubt that the Sun’s magnetic field is central to understanding the activity on “our” star. But is it really significantly related to Einstein (in particular to the validity of General Relativity) and climate (the global warming acting over the last century)? Come and find out.

	Special Colloquium
Prof. Jacques Roland	ORATED

Institut d'Astrophysique, Paris, France

Radio loud active galactic nuclei present a remarkable variety of signs indicating the presence of periodical processes possibly originating in binary systems of supermassive black holes, in which orbital motion and precession are ultimately responsible for the observed broad-band emission variations, as well as for the morphological and kinematic properties of the radio emission on parsec scales. This scenario, applied to the quasar 3C345, explains the observed variations of radio and optical emission from the quasar, and reproduces the structural variations observed in the parsec-scale jet of this object. The binary system in 3C 345 is described by two equal-mass black holes with masses of 7*108 solar masses separated by 0.33 pc and orbiting with a period of 480 years. The orbital motion induces a precession of the accretion disk around the primary black hole, with a period of 2570 years. The jet plasma is described by a magnetized, relativistic electron-positron beam propagating inside a wider and slower electron-proton jet. The combination of Alfvén wave perturbations of the beam, the orbital motion of the binary system and the precession of the accretion disk reproduces the variability of the optical flux and evolution of the radio structure in 3C345.

	Main Colloquium
Dr. Guinevere Kauffmann	ORATED

Max-Planck-Institut für Astrophysik, Garching bei München

The Sloan Digital Sky Survey (SDSS) is the most ambitious astronomical survey project ever undertaken. It is using a dedicated 2.5-meter wide-field telescope at the Apache Point Observatory in New Mexico to conduct an imaging and spectroscopic survey of about a quarter of the extragalactic sky. When the current survey is complete, spectra will have been obtained for nearly a million galaxies, providing a 3-dimensional map of the Universe through a volume about a hundred times bigger than before. Unlike previous redshift surveys, the spectra in the SDSS are of extremely high quality and are very well suited to the determinations of the principal properties of the stars and the ionized gas in galaxies. The stellar absorption lines in the spectra constrain the ages and metallicities of the stars in a galaxy. The nebular emssion lines constrain the metallicity , the ionization parameter and the dust-to-heavy element ratio in the gas. The properties of the emission lines also allow us to identify galaxies with active galactic nuclei (AGN). I will discuss how the physical properties of galaxies correlate with each other and how they depend on environment (as deduced from our 3-dimensional map). The very large number of galaxies in the survey will enable us to split the sample many different ways and explore how the interplay of galaxy environment, mass, structure and the presence of a black hole has influenced a galaxy’s evolutionary history. I will discuss the implications of these results for models of galaxy formation based on the standard “hierarchical clustering” paradigm for structure formation in the Universe.

	Special Colloquium
Prof. William Forman	ORATED

Center for Astrophysics, Boston

We present Chandra, ROSAT, and XMM-Newton observations, combined with detailed radio maps, to study the impact of AGN outbursts on gaseous atmospheres in early type galaxies, groups, and clusters. We focus the discussion on M87 where many X-ray features appear to be a direct result of repetitive AGN outbursts. In particular, the X-ray cavities around the jet and counter jet are likely due to the expansion of radio plasma, while rings of enhanced emission at 14 and 17 kpc are probably shock fronts associated with outbursts that began about 10-20 million years ago. The effects of these shocks are also seen in brightenings within the prominent X-ray arms. On larger scales, about 50 kpc from the nucleus, depressions in the surface brightness may be remnants of earlier outbursts. As suggested for the Perseus cluster, our analysis of the energetics of the M87 outbursts argues that shocks may ba a significant channel for AGN energy input into the cooling flow atmospheres of galaxies, groups, and clusters. For M87, the mean power driving the shock outburst is three times greater than the radiative losses from the entire “cooling flow”. Even in the absence of other energy inputs, outbursts every 30 million years are sufficient to quench the flow.

	Main Colloquium
Dr. Sergej Moiseenko	ORATED

Space Research Institute, Academy of Sciences, Moscow, Russia

We present 2D results of simulations of the magnetorotational core collapsed supernova. For the first time we obtain strong explosion for the core collapsed supernova. In 2D approximation we show that amplification of the toroidal magnetic field due to the differential rotation leads to the formation of MHD shockwave, which produces supernova explosion. The amounts of the ejected mass and energy can explain the energy output for supernova type II or type Ib/c explosions. The shape of the explosion is qualitatively depends on the initial configuration of the magnetic field, and may form strong ejection near the equatorial plane, or produce mildly collimated jets. We discuss the violation of the mirror symmetry of the supernova explosion in magnetorotational mechanism and possible explanation for the origin of the observed rapidly moving neutron stars.

	Special Colloquium
Marusa Bradac	ORATED

Uni-Bonn

One of the main problems in cosmology is to understand the formation and evolution of galaxies, galaxy clusters, and large-scale structure. Whereas the basics of the current Cold Dark Matter (CDM) paradigm for structure formation are widely accepted, some controversial issues for CDM (e.g. cuspiness of dark-matter halos, substructure crisis) still remain. In order to test CDM predictions, one needs to investigate bound objects from the smallest (dwarf galaxies) to the largest (galaxy clusters) scales at different redshifts. In particular, their matter-content, luminous and dark, has to be studied in detail. In this colloquium I will address these issues by using gravitational lensing. Specifically, I will explain how I explore the properties of mass-substructure and the mass-profiles of galaxies, as well as the mass-profiles of galaxy clusters, using strong and weak gravitational lensing.

	Main Colloquium
Dr. Bernd Aschenbach	ORATED

Max-Planck-Institut für extraterrestrische Physik, Garching bei München

The 3:2 twin high frequency quasi-periodic oscillations of some galactic microquasars are interpreted as a parametric resonance between the polar and radial epicyclic oscillations of matter orbiting a rotating black hole of stellar type mass. The quasi-periods recently found by us to be present in the flares of the Galactic Center supermassive black hole Sgr A* can be interpreted in the same way. The combined analysis reveals a unique value for the angular momentum of these black holes. The mass of the black hole is given by just the measured upper-most frequency. The values for the orbital radius and the angular momentum could be verified as being special by a detailed analysis of the classical problem of a test-particle orbiting a rotating black hole using the general relativistic Boyer-Lindquist functions. If the black hole angular momentum exceeds a value of 0.9953 the orbital velocity does no longer change monotonically with orbital radius, which is new effect of strong gravity. I will discuss some of the implications.

	Main Colloquium
Dr. habil. Claus E. Ascheron	ORATED

Executive Editor Physics, Springer Verlag, Heidleberg

The Nobel Prize is the most famous and prestigious of all scientific awards. Many scientists dream of getting it, but only very few succeed. There are many mysterious and interesting problems connected with this prize. In the presentation it will be discussed: 2   ullet The history of the Nobel Prize   ullet New trends in awarding the Nobel Prize (basic versus applied research)   ullet How Nobel Prizes reflect the development of science   ullet Were all the decisions of the Nobel Prize committee correct?   ullet How are the decisions of the Nobel Prize committee made?     - proposal, first-round selection, decision   ullet Distribution of Nobel Prizes among nations     - Trends in the regional distribution     - Nobel Prizes as a measure of national scientific creativity     - Political influences   ullet The Nobel Prize as an indicator of the quality of research       - Distribution among the worldŽs leading scientific institutes   ullet Correlation between Nobel laureates and highly cited scientists   ullet Correlation of the number of Nobel Prizes with balance of trade and with national investment in research   ullet Individual distribution of Nobel Prizes     - Gender     - Family     - Multiple awards   ullet Prize money   ullet Other prestigious awards in science and mathematics   ullet Profile of a Nobel Laureate     - A guide to winning the Nobel Prize

	Special Colloquium
Dr. Helmut Jerjen	ORATED

Research School of Astronomy and Astrophysics, Mt. Stromlo Observatory, Australia

The epoch of the galaxy formation must leave an imprint in the properties of the mass function of collapsed objects and in its observational manifestation the luminosity function. At present the faint end of the luminosity function of galaxies is poorly understood. I will discuss how technical and methodical developments over the last few years provide the capability to identify dwarf galaxy candidates and to measure distances to very faint levels which will lead to accurate knowledge of the luminosity function over the full range of galaxy clustering scales. This will provide crucial input to constrain both the initial cosmological conditions and the modulating astrophysical processes.

	Main Colloquium
Prof. Martin Harwit	ORATED

Auswärtiges wissenschaftliches Mitglied MPIfR (Cornell University)

TBA

	Special Colloquium
Prof. Philipp Kronberg	ORATED

University of Toronto, Canada

A sequence of only partly understood processes is responsible for the largest energy transfers in the Universe. Via collimated jets, energy is coupled from close to the central black hole, and injected into intergalactic space. In this process, the magnetic energy released is of comparable order to what the BH releases in photons. The high conversion efficiency of gravitational- to magnetic- and CR- energy, in addition to other arguments suggest that magnetic reconnection rather than shock acceleration are a primary CR acceleration mechanism in extragalactic space.

	Special Colloquium
Dr. Olaf Wucknitz	ORATED

MPIfR

B0218+357 is one of the best candidates to determine the Hubble constant from the time delay of a gravitational lens, if —but only if— all the available data are used as constraints for the mass models. Our work for the first time utilizes the structure of the nice Einstein ring in this system in order to determine the position of the lens. In this talk I review the published results and present a preliminary analysis of a new data set taken with the VLA + Pie Town, which has the potential to reduce the uncertainties dramatically. A further result is the first reconstruction of the polarization structure of the source.

	Special Colloquium
Prof. Renée Kraan-Korteweg	ORATED

Departamento de Astronomía, Universidad de Guanajuato, Mexico, currently on sabbatiacal at the ATNF (CSIRO), Epping, Aust

Results will be presented from systematic surveys in the lambda21cm line for galaxies obscured by the dust and stars of the Milky Way. Hi-surveys are the only observing method that penetrate without hindrance the regions in the sky that remain opaque in the visible and infrared. I will talk in detail about the deep Hi survey made along the Galactic Plane (|b| < 5.25) with the MultiBeam Receiver of the 64-m Parkes radio telescope and the uncovered extragalactic large-scale structures—in particular in the Great Attractor region. I will end with the description of a supermassive galaxy detected in this survey.

	Main Colloquium
Dr. Tiziana di Matteo	ORATED

Max-Planck-Institut fuer Astrophysik, Garching

Galaxy formation and the growth of supermassive black holes appear to be mutually intertwined processes, to the point that they require joint theoretical modelling to be meaningfully addressed. I will present results of novel hydrodynamical simulations which simultaneously follow star formation black hole accretion, and their associated feedback processes, during major mergers of galaxies. I will discuss black hole growth in the centers of galaxies and their impact on galaxy formation.

	Special Colloquium
Elmar Koerding	ORATED

MPIfR

In this talk I present a symbiotic disk/jet model for active galactic nuclei (AGN) and black hole X-ray binaries. Energy and mass conservation are used to derive scaling laws for the emission of a jet and allow us to identify the main parameters of the system: the mass of the central black hole and the accretion rate. The developed model can be used to argue for a unifying view of all weakly accreting black holes: a unification of XRBs and AGN. I classify the zoo of AGN in jet and disk dominated sources and test the unification scheme of weakly accreting sources by establishing a universal radio/X-ray correlation for XRBs and AGN. The model will be further tested by studying the phenomenom of ultra-luminous X-ray sources and the short time variablity of black hole XRBs and AGN.

	Main Colloquium
Prof. Steve Rawlings	ORATED

Astrophysics, University of Oxford

TBA

	Special Colloquium
Dipl.-Phys. Oliver-Mark Cordes	ORATED

Uni-Bonn

TBA

	Main Colloquium
Dr. Sebastian Wolf	ORATED

Max-Planck-Institut fuer Astronomie, Heidelberg

Planets are expected to form in circumstellar disks, which are considered as the natural outcome of the protostellar evolution, at least in the case of low and medium mass stars. While a detailed picture of the evolution of the circumstellar environment, in particular of circumstellar disks, has been developed already, the planet formation process is in major parts still under discussion. Based on selected observations and numerical simulations, I will discuss several aspects of the observability of the planet formation process in circumstellar disk. For example, I will present studies on the grain growth in the circumstellar disk of the Butterfly star in Taurus and predictions of observable quantities of giant planets in circumstellar disks in different evolutionary stages.

	Special Colloquium
Dr. Michael Smith	ORATED

Armagh Observatory, Armagh, Northern Ireland

TBA

	Main Colloquium
Dr. Emilios Harlaftis	ORATED

National Observatory of Athens, Greece

A review of spiral shocks in accretion disks of cataclysmic variables will be given. Their observation gives support for theories of migration of ``Hot-Jupiters" and the conversion of the initial protostellar disk into a planetary system. Methods of numerical simulations are presented which highlight their origin as tidal waves raised by the donor star on the white dwarf’s accretion disk. The observed spiral shocks are imaged as emitting structures using MEM reconstruction techniques such as Doppler tomography (from phase-resolved spectra) and eclipse mapping (from eclipse light curves) giving insight into the physics of accretion disks at the micro-arcsecond level. The techniques, spectra, maps and simulations using these techniques are presented in order to demonstrate how the local physics of an accretion disk can be constrained.

	Special Colloquium
Dr. Luca Moscadelli	ORATED

Osservatorio Astronomico di Cagliari, Sardinia, Italy

We are carrying on multi-epoch VLBI observations of 22.2 GHz water masers towards selected samples of both low-mass and high-mass Young Stellar Objects (YSOs). Achieving angular resolution of sim1 mas, VLBI H_2O maser observations allow to study the gas kinematics in the close proximity (at distances le 100 AU) of the forming (proto-)star. Multi-epoch observations spread over a time baselines of (only) a few months, consent to measure the proper motions (and the line of sight velocities) of the maser fatures, and hence to derive the full 3-dimensional velocity structure of the environment traced by the water masers. Toward low-mass YSOs, our goal is to study the evolution of the disk/jet system as a function of the YSO evolutionary stage. Relevant questions as the jet acceleration and collimation mechanism can be addressed. Towards high-mass YSOs, water maser VLBI observations can help to address the fundamental problem of their formation mechanism, by investigating the presence of an accretion disk around the forming (proto-)star. This talk presents the first results obtained from the on-going observational program.

	Special Colloquium
Dr. Lars Fuhrmann	ORATED

MPIfR

The Large Area Telescope (LAT), onboard the Fermi Gamma-ray Space Telescope (Fermi GST; formerly GLAST, launched June 11, 2008) is a pair conversion telescope designed to study the gamma-ray sky in the energy range from 20 MeV up to 300 GeV. Since its initial check-out phase (July/August 2008), the LAT performs extraordinary well, delivers detailed gamma-ray data for a large number of sources and produces a deeper and better-resolved view of the gamma-ray sky than any previous space mission. After a general overview/summary of the major results obtained during the first months of operation, I will particularly focus on Fermi AGN/blazar science and our Fermi-related activities here at MPI (e.g. the F-GAMMA project).

	Main Colloquium
Prof. José C. Guirado	ORATED

Universitat de València, Spain

TBA

	Special Colloquium
Brad Warren	ORATED

Mount Stromlo Observatory, Weston, Australia

I will discuss a multiwavelength investigation of a sample of high HI mass-to-light ratio dwarf galaxies selected from the HIPASS Bright Galaxy Catalog (BGC) which we have done using the ANU 2.3-m Telescope and the Australia Telescope Compact Array. Galaxies which still maintain large quantities of unprocessed neutral hydrogen (HI) compared to their stellar content are important for near field cosmology as they suggest the existence of unevolved dark galaxies. Within these galaxies star formation may have been impaired or halted, has lacked stimulation, or has only recently begun. I will discuss the global stellar and HI properties, HI dynamics, star formation rates, isolation, and gas surface density thresholds in our sample galaxies to try and explain why these galaxies have retained their primordial gas content while other galaxies have processed their gas into stars. In particular I will focus on the galaxy ESO215-G?009, a nearby low surface brightness dwarf irregular galaxy which to our knowledge has the highest HI mass-to-light ratio for a galaxy to be confirmed by accurate measurement to date.

	Main Colloquium
Maria Messineo	ORATED

Leiden Observatory, The Netherlands

Asymptotic Giant Branch (AGB) stars are good tracers of the Galactic structure. They are bright in the infrared and can therefore be detected even in the most obscured regions of the Galaxy. Maser emission from their circumstellar envelopes can be detected throughout the Galaxy, and reveals the stellar line-of-sight velocities with an accuracy of a few km/s. Our SiO maser survey of AGB stars was able to detect 255 new maser sources, thereby doubling the number of known stellar line-of-sight velocities toward the inner Galaxy. The longitude-velocity diagram of the SiO maser stars clearly reveals a stellar Galactic nuclear disk and suggests that they are related to the bar component. Using DENIS, 2MASS, ISOGAL, MSX and IRAS photometry, we can study the nature of the masing stars, deriving their luminosities and mass-loss rates, and establishing them as mostly variable AGB stars. In deriving extinction corrections from the surrounding field population colors, we were also able to constrain the near-infrared extinction law toward the inner Galaxy.

	Special Colloquium
Prof. Gordon Stacey	ORATED

Cornell University, Ithaca, NY, USA

I will present a discussion of the current and future research in submillimeter astronomy at Cornell University. I will begin by highlighting results obtained using our submillimeter imaging spectrometer, the South Pole Imaging Fabry-Perot interferometer, SPIFI on the 15 m JCMT. These results include mapping in the CO(7-6) and [CI] 370 um lines of the Galactic Center, and external starforming galaxies. I will also discuss our current research with SPIFI on the 1.7 m AST/RO telescope at the South Pole. Next, I will present a discussion of our submillimeter echelle grating spectrometer, the redshift (z) and Early Universe Spectrometer (ZEUS). ZEUS is designed for use in the 350, 450, and 610 um windows available to the JCMT and the 12 m APEX telescope at Chajnantor. Our primary goal with ZEUS is to detect redshifted [CII] 158 um line emission from distant submillimeter galaxies. Finally, I will discuss the new project to build a 25 m class submillimeter telescope at a high Atacama site, a collaborative project between the submillimeter group at Caltech and the Astronomy Department at Cornell.

	Informal Colloquium
Prof. Peter Hofner	ORATED

New Mexico Tech & NRAO, Socorro, NM, USA

Massive Stars play an important role in most areas of astronomical research yet our knowledge about the physical processes leading to their formation is extremely scarce. The fundamental question is how tens of solar masses can be assembled into a star in the presence of strong radiation pressure from the central object. Disk accretion is a possible answer and I will present results of a project which approaches this question observationally, namely a search for accretion disks around young massive stars using the 7 mm dust emission as a tracer.

	Special Colloquium
Dr. Geoffrey Bicknell	ORATED

Mount Stromlo Observatory, Weston, Australia

When we view a classical double radio source, we are viewing the end point of evolution over the last 10^{7-8} yrs or so. We get some idea of the early stages of radio galaxies by looking at GPS and CSS radio sources, which are clearly interacting with a clumpy interstellar medium that may be the debris from a fairly recent merger. Simulations of jets in radio galaxies with an inhomogeneous medium reveal some fascinating detail of what the evolution from the GPS to the classic phase is like. Structures, very similar to many well known radio galaxies are produced. Our most recent three-dimensional simulations produce structures resembling very strongly both the X-ray and radio morphology of CygnusA. The initial stages of this work were the result of a collaboration with Curtis Saxton and Ralph Sutherland with the most recent work involving Ralph Sutherland and myself.

	Special Colloquium
Viola Tegethoff	ORATED

Scientific Officer, MPG Office in Brussels

Workshop (from 11:00 to 13:00) - The Marie Curie Actions: * Research Training Networks * Series of Conferences and Training Courses * Funding possibilities for the Postdoc-Phase * Excellence Grants * Excellence Chairs * How to write a competitive proposal * The evaluation process Individual consultation (after reservation) at 14:00-18:00 and at 10:00-13:00 on August 3rd

	Special Colloquium
Uwe Bach	ORATED

MPIfR

This talk will summarise recent results from VLBI observations of two radio sources that are the most representatives of their AGN class: the BL Lac object 0716+714 and the FRII radio galaxy Cygnus A. Both are important test objects and they offer the opportunity to study the physics of jets from two different perspectives. A nearly face-on view is offered by the blazar 0716+714 and an edge-on view by Cygnus A. I will discuss the kinematical properties of the jets and compare them with different jet models. A detailed analysis of the spectral properties of the inner few parsecs of the core region of Cygnus A strongly supports the existence of a circumnuclear absorber as it is predicted by unifying schemes. 0716+714 is a famous intraday variable source. Multi-epoch Space VLBI observations combined with simultaneous flux density measurements with the 100 m Effelsberg were performed. The single-dish analysis shows variability in total intensity and linear polarisation between the epochs, and the VLBI imaging reveals for the first time that the origin of the variability is at the core component of 0716+714.

	Special Colloquium
Dr. Anvar Shukurov	ORATED

University of Newcastle, UK

TBA

	Special Colloquium
Dr. Anvar Shukurov	ORATED

University of Newcastle, UK

TBA

	Main Colloquium
Dr. Kandaswamy Subramanian	ORATED

Inter-University Institute for Astronomy and Astrophysics, Pune, India

The origin of large scale cosmic magnetic fields remains an intriguing problem. This talk explores the consequences of assuming that they could be of primordial origin, a remnant of the early univrese. After briefly discussing possible generation mechanisms, I consider their evolution in the early universe, their impact on structure formation, and then focus on the CMBR anisotropy induced by such fields. A scale invariant spectrum of tangled magnetic fields which redshifts to a present value of 3 nano Gauss produces a temperature anisotropy of order 3-10 micro Kelvin, at the arc minute scales and could contribute significantly to the excess power seen in the Cosmic Background Imager (CBI) experiment. Such fields also induce a characteristic B-type polarization anisotropy of 0.3-0.4 micro Kelvin at high l > 1000, which could be probed by future experiments like PLANCK. Early structure formation induced by such fields may also be relevant to explain the early re-ionization inferred from the WMAP data. We may be on the verge of detecting or ruling out primordial fields which are strong enough to impact significantly on structure formation.

	Special Colloquium
Prof. G. L. Tyler	ORATED

Center for Radar Astronomy, Stanford University, CA, USA

Radio occultation has now been applied to all atmospheres of our solar system with the exception of Pluto’s. Developments of the past few years have filled out the theoretical foundations of the method providing an analytical theory of errors. Current issues include optimization of experimental design for application to the Earth’s atmosphere and separation of the effects from poorly mixed atmospheric constituents. An experiment being prepared for launch to Pluto is designed to characterize an atmosphere with a surface pressure in the range of 3 microbars.

	Main Colloquium
Dr. Gerhard Wurm	ORATED

Institut für Planetologie, Universität Münster

It is widely accepted that (terrestrial) planets form through collisions of smaller bodies initially starting off as micrometer-size dust grains in protoplanetary disks. While the first steps on the way up to cm-size can easily be understood in terms of simple hit-and-stick collisions, the formation of larger bodies is more challenging. Collision velocities can reach up to more than 50m/s and it is by far not trivial to stick two bodies together at these “high” speed collisions. Usually fragmentation and thus erosion is observed rather than growth. So the fundamental question remains: is it possible at all to grow something larger in spite of the destruction? The answer is probably yes. I will present some ideas and experiments which show that under a wide range of conditions the gas in protoplanetary disks will help recollecting fragments from a collision. This can turn the erosion after a primary impact to net growth by secondary collisions. While this might explain the formation of planetesimals this mechanism also feeds the dust reservoir so that small dust grains can be present in protoplanetary disks on all timescales. Growth as well as fragmentation will determine how the dust particles look like. This will influence the way these dust particles move in protoplanetary disks, how they interact with light, and how eventually they might be seen in astronomical observations. Some results of our current research (mostly in experiments) with respect to the optics of dust grains will also be presented.

	Special Colloquium
Dr. Sebastian Jester	ORATED

Fermilab

By analogy to the different accretion states observed in black-hole X-ray binaries (BHXBs), it appears plausible that accretion disks in active galactic nuclei (AGN) undergo a state transition between a radiatively efficient and inefficient accretion flow. I show how to test for the reality of this transition in AGN by considering the distribution of black hole masses and bolometric luminosities. The analogy has implications for the differences between radio-loud and radio-quiet AGN. I describe a program to test for a division between two types of AGN using volume-limited subsets of the SDSS quasar sample with FIRST matches.

	Main Colloquium
Prof. Jacqueline van Gorkom	ORATED

Columbia University

It has been known for more than 50 years that galaxies in the dense core of clusters differ from those in the field in their morphological mix and star formation activitity. Recent optical surveys have quantified these so called density-morphology, density-luminosity and mass-morphology relations. Yet, the nature versus nurture debate is more alive than ever. I will present the results of an imaging survey in the neutral hydrogen line of clusters in the local universe (0 < z < 0.2). These data elucidate which physical mechanisms affect galaxies as they enter denser environments. I will compare observations on individual galaxies with results of simulations and I will speculate on possible relations between the cluster dynamical state and its cold gas content.

	Special Colloquium
Dr. Mark Reid	ORATED

Harvard-Smithsonian Center for Astrophysics, Cambridge, MA, U.S.A.

I will describe measurements with the VLBA of the position of Sgr A* with respect to two extragalactic radio sources over a period of eight years. The apparent proper motion of SgrA^* relative to J1745-283 is almost entirely along the plane of the Galaxy. The effects of the orbit of the Sun around the Galactic center can account for this motion, and the residual proper motion of SgrA^* is exceedingly small. I will show how an upper limit on the motion of SgrA^* implies a lower limit to its mass. This mass limit, coupled with upper limits to the apparent size of SgrA^*, provides overwhelming evidence that SgrA^* is a super- massive black hole. Our observations provide the first direct evidence that a compact radio source at the center of a galaxy contains sim10^6 Modot. Also, the existence of ``intermediate mass" black holes near the Galactic Center are strongly constrained by our observations.

	Special Colloquium
Dr. Andreas Brunthaler	ORATED

MPIfR

Here, I will report the detection of the proper motions of two Local Group galaxies, namely M33 and IC10. The proper motions were measured by phase-referencing VLBI observations of H_2O masers in the galaxies with respect to nearby background quasars. These results can be used to constrain kinematic models of the Local Group. Also, a geometric distance to M33 could be measured. The method is to measure the relative proper motions of H_2O maser sources on opposite sides of M33. The measured angular rotation rate, coupled with other measurements of the inclination and rotation speed of the galaxy, yields a direct distance measurement.

	Main Colloquium
Dr. Michael Kachelriess	ORATED

Max-Planck-Institut fuer Physik, Muenchen

After a brief review of ultra-high energy cosmic ray (UHECR) and neutrinos experiments, I discuss in detail the currently most disputed issues in UHECR physics: energy spectrum and GZK cutoff, the small-scale clustering of arrival direction, and attempts to identify sources. Apart from astrophysical sources, I review also the status and signatures of proposals that involve particle physics beyond the standard model.

	Special Colloquium
Dr. Moshe Elitzur	ORATED

Department of Physics and Astronomy, University of Kentucky, U.S.A.

TBA

	Special Colloquium
Dr. Thomas Beckert	ORATED

MPIfR

TBA

	Special Colloquium
Dr. Moshe Elitzur	ORATED

Department of Physics and Astronomy, University of Kentucky, U.S.A.

The variety of observations of Active Galactic Nuclei (AGN) have been classified with a simple unified scheme: The nuclear activity is powered by a central massive black hole that drives radio emitting jets and ionizes surrounding line-emitting clouds. The whole system is surrounded by a dusty torus and the observer’s orientation with respect to this obscuring torus determines the appearance of the AGN. Pole-on viewing gives rise to superluminal jets and Seyfert 1 line spectrum, edge-on results in extended radio lobes and Seyfert 2 lines. The torus is comprised of optically thick dusty clouds in a rotating configuration with roughly equal vertical and radial dimensions. Although the observed IR is in broad agreement with the expected effects of the dusty torus, detailed properties of the spectral energy distribution (SED) posed difficult problems. The dynamical origin of the rotating cloud configuration, and especially the maintenance of its vertical height, present an even more serious challenge. We have recently developed a formalism to handle radiative transfer in clumpy media and in this talk I show that the SED problems find a natural explanation if the dust is contained in about 5–10 clouds along radial rays through the torus. Furthermore, the properties of the model SED may also provide the answer for the torus dynamical origin.

	Main Colloquium
Dr. habil. Jürgen Steinacker	ORATED

Max-Planck-Institut für Astronomie, Heidelberg

The formation of stars and planets from cloud fragments is still a poorly understood process. The key questions of initial conditions, fragmentation and binarity, accretion physics and angular momentum transport, and planet growth are unanswered. To overcome this, on the theoretical side, increasingly sophisticated 3D SPH and HD simulations are applied. They aim to derive densities, velocities, and temperatures of matter involved in the formation process. On the observational side, adaptive optics and interferometric measurements are now able to resolve and characterize sites of star-formation at many wavelengths. As natural connection between both approaches, 3D radiative transfer calculations can produce maps and spectra of theoretical models or fit images. The numerical problem of 3D radiative transfer is briefly touched. We present the first 3D density and temperature distribution of a molecular cloud core obtained from a multi-wavelength analysis. Based on a Smoothed Particle Hydrodynamics simulation of a molecular cloud core evolution, we present images of the collapsing core at different wavelengths and evolution times. We discuss verification of magneto-spherical accretion onto a T Tauri star for the case of AA Tau. The maximal spectral impact of a gap in an accretion disk produced by a forming planet is derived by a global search of the SED parameter space. We present images and animations of “planetary” gaps in accretion disks and discuss the observability with an interferometer. For the first massive disk candidate seen in absorption, we report our progress in modeling the NIR images.

	Main Colloquium
Prof. Rien van de Weyjgaert	ORATED

Kapteyn Instituut, Groningen, The Netherlands

Reconstructing density or intensity fields from a set of irregularly sampled data is a common issue in operations on astronomical data sets, both in an observational context as well as in the context of numerical simulations. Here we present the DTFE method for obtaining in a fully self-adaptive fashion the volume-covering reconstruction of density and velocity fields. The method uses a point set’s Voronoi tessellation for density estimation, and its Delaunay tessellation as multidimensional interpolation interval. The key virtues of the method are its ability to preserve the anisotropic and hierarchical nature of spatial patterns in point distributions. The presentation will discuss its application to the 2dFGRS and SDSS galaxy redshift surveys, the application to the analysis of density, velocity and other dynamical fields in large N-body simulations of structure formation, and the first results of a promising extension as a possible new tool in a moving grid astrohydro code.

	Main Colloquium
Dr. Stefanie Komossa	ORATED

MPIfR

There is now growing evidence that supermassive black holes reside at the centres of most galaxies, and that there is an intimate link between their formation and evolution and that of their host galaxies. Throughout the history of the universe, galaxies will merge frequently with each other, forming binary black holes at their centres, and an active search for these binaries is currently ongoing. During the final coalescence of the two black holes, linear momentum imparted by gravitational waves produces a kick, and the newly formed single black hole will recoil from the centre of its host galaxy. The presence of supermassive binary black holes and recoiling black holes has a wealth of astrophysical implications which are currently being explored including consequences for structure formation in the early universe and black hole growth, for unified models and the evolution of active galaxies, and for black hole - galaxy scaling relations. I will give an overview of the observations and predicted electromagnetic signatures of massive black hole binaries and recoiling black holes, including future schemes to search for electromagnetic counterparts to their gravitational wave signals, and I will discuss astrophysical implications.

	Main Colloquium
Dr. Hans-Rainer Klöckner	ORATED

Kapteyn Institute, Groningen & ASTRON, Dwingeloo, The Netherlands

Extra galactic emission from the hydroxyl and the water molecule was first detected in the early eighties, revealing a new class of maser emission with unexpected isotropic luminosities of many magnitudes higher than their galactic counterparts. Galaxies that harbor this so-called Megamaser emission show enhanced core activity in the form of a nuclear starburst or an active-galactic-nucleus. The exceptional maser properties together with the nuclear activity indicate that the line radiation originates in the circumnuclear environment. Additionally to the exceptional maser emission, hydroxyl also has been detected with extreme broad absorption features also revealing information of the circumnuclear environment of similar types of host galaxies. But observation at parsec-scale resolution a rather more complex picture of the molecular environment, which needs to be investigated on particular bases for each galaxy. One part of the here presented research uses very-long-baseline-interferometry in order to investigate the OH emission and the OH absorption seen in there individual galaxies at parsec-scale resolution. Since the first detection of OH Megamaser emission, about 20 year ago, the sample of such galaxies increase quite slowly. Therefore detection experiments are performed in order to reveal hydroxyl and to increase the sample of such galaxies. Furthermore, on the bases of the compiled data sample, general properties of OH Megamaser source are still main issues of research and have been reviewed and whenever appropriate compared with galaxies showing OH in absorption. The general characteristic of the exceptional OH emission is still barely understood and has been investigated by using general properties of the host galaxies. Finally a model of the geometric structure traced by the OH emission in the circumnuclear environment have been developed and first results are presented.

	Special Colloquium
Dr. David Bacon	ORATED

Royal Observatory, Edinburgh, UK

The cosmic distribution of dark matter in 3-D is a matter of great interest. A detailed knowledge of this distribution would allow us to measure post-WMAP cosmological parameters; to engage in detailed astrophysics of the gravitational environments of baryons; and to measure directly the evolution of structures in the Universe. A promising means of achieving these goals is offered by new techniques combining weak gravitational lensing analysis with photometric redshifts. I will discuss our application of these techniques to the COMBO-17 survey, which offers =  1 sq deg of good quality imaging data together with photometric redshifts with Delta z <  0.05 for z<1. In particular, I will present our first 3-D map of the gravitational potential in a 3x105 (h-1 Mpc)3 volume, and our measurements showing the evolution of large-scale structures for z<1.

	Main Colloquium
Dr. Areg Mickaelian	ORATED

Byurakan Astrophysical Observatory, Armenia

The Markarian survey, or (officially) the First Byurakan Survey (VBS), is the largest spectroscopic survey covering 17,000(^circ)^2 at high galactic latitudes. 1500 Markarian galaxies, thousands of blue stellar objects and late-type stars have been discovered and optical identifications of 1600 IRAS sources have been made using this observational material. Some 20,000,000 spectra are present in FBS giving a key to understanding of the nature of these objects. The project of digitization of FBS has brought to creation of a unique database: the Digitized First Byurakan Survey (DFBS). At present all FBS plates have been scanned and reduction software is being created and applied. An automatic selection of different types of interesting objects will be possible and searches for new bright QSOs, faint Markarian galaxies, white dwarfs, cataclysmic variables, carbon stars, as well as optical identifications of radio, IR and X-ray sources will be undertaken.

	Special Colloquium
Dr. Wouter Vlemmings	ORATED

Cornell University

Recently we have been able to make the first measurements of the magnetic fields in the water maser region of a small sample of late-type stars. Field strengths between 0.1 and 2 Gauss were measured by Very Long Baseline Array (VLBA) observations of the circular polarization caused by the Zeeman effect. Here I will discuss the observations and analysis method and also present new results on additional stars. These include the first observations of magnetic field structure in the water maser region of VX Sgr, matching the structure seen in the OH masers much further out in the maser shell.

	Main Colloquium
Prof. Richard T. Schilizzi	ORATED

Square Kilometre Array (International Director), Dwingeloo, The Netherlands

The colloquium will give an update on progress in the Square Kilometre Array project to develop the next generation radio telescope at metre to centimetre wavelengths. The telescope will have a collecting area of order one million square metres, a sensitivity 50 times higher than the extended VLA, an instantaneous field of view (FOV) larger than the full moon, and, in some designs, more than one FOV allowing multiple simultaneous use. It will be an extremely powerful survey telescope with the capability to follow up individual objects with high angular and time resolution. The SKA will reach a point source sensitivity of 25 nano-Jy in 1 hour of integration, and a maximum resolution of better than 1 milli arcsec at 20 GHz with the gola of excellent imaging at any given frequency. The SKA science reach will be enormous, allowing new discoveries in cosmology, fundamental physics, galactic and extragalactic astronomy, and solar system science. Technological innovation, closely paralleling commercial IT developments, is key to the design concepts under investigation and to the cost goal of USD1000/m^2. The selection of technologies for the SKA is scheduled in early 2008. A number of possible locations for the telescope are under investigation with a choice scheduled in early 2006. Construction of the array will take most of the next decade.

	Special Colloquium
Prof. Anthony Readhead	ORATED

California Institute of Technology, Pasadena, CA, U.S.A.

TBA

	Special Colloquium
Dr. Henrik Olofsson	ORATED

Onsala Space Observatory, Gothenburg, Sweden

Odin is a small yet versatile and capable orbiting radio telescope for astronomy and aeronomy operating in the mm and submm bands. It is equipped with 5 heterodyne SSB receivers (4 tunable around 0.55 mm, and one fixed tuned at 2.5 mm) connected to a 1.1 m parabolic aperture, allowing access to important rotational emission lines from molecules such as H_2O, O_2, NH_3 and more. Odin is a collaborative project between Sweden, Canada, France, and Finland with Sweden as the leading participant. It was successfully launched on 20 February 2001 and has operated in good health ever since. Included in this talk will be a review of the mission since launch time as well as a description of some the scientific astronomical results so far.

	Informal Colloquium
Dr. Alberto Carraminiana	ORATED

INAOE, Tonantzintla, Puebla, Mexico

TBA

	Special Colloquium
Enno Middelberg	ORATED

MPIfR

We have a project to measure magnetic fields in the obscuring tori of AGNs. We observed five free-free absorbed jets in radio galaxies with polarimetric VLBI at 15 GHz to determine Faraday rotation measures. Surprisingly, all sources are unpolarized, putting severe constraints on the degree of magnetic field turbulence and the gas distribution in these objects. We have further carried out multi-frequency VLBI monitoring of the Seyfert 2 galaxy NGC 3079 and find unusually steep and inverted spectra in the radio components, and derive general properties of Seyfert galaxies using published VLBI observations of Seyfert galaxies. We have developed a new phase-referencing technique for high frequency VLBI observations with the VLBA. Instead of inserting short scans on a calibrator into the target source observations, the target source is continuously observed while rapidly switching between the target frequency and a lower reference frequency. We demonstrate that the technique allows phase calibration almost reaching the thermal noise limit and present the first detection of the AGN in NGC 4261 at 86 GHz. This is the weakest source ever detected with VLBI at that frequency.

	Main Colloquium
Multiple Speakers: Check abstract for details	ORATED

Speaker: Prof. M. Römer / Dr. J. Overduin / Prof. H. Dehnen / Prof. H. J. Blome Affiliation: Uni-Bonn / U. Stanford, CA, USA / Konstanz / Aachen

	Main Colloquium
Dr. Yoshiaki Hagiwara	ORATED

ASTRON

Significant advances in studies of 22 GHz extragalactic water masers have been made since the discovery of the extragalactic water maser in M33 by Ed Churchwell et al. with the MPIfR 100-m radio telescope. Radio synthesis imaging of ’nuclear’ water masers has proved that they are tools for probing the kinematics of circumnuclear regions in Active Galactic Nuclei (AGNs). Observations made with the Effelsberg 100-m have contributed very much in discovering not only for those intense nuclear masers which are found mostly towards narrow-line AGNs but also for weak water masers in extragalactic star-forming sites. This talk will briefly review the studies of these extragalactic water masers, and then review several recent results, highlighting some made with the MPIfR 100-m. Some interpretations and origins of these masers will be discussed.

	Special Colloquium
Dr. Naomi McClure-Griffith	ORATED

Australia Telescope National Facility

TBA

	Special Colloquium
Dr. Kaustuv moni Basu	ORATED

AIfA

The metallicity evolution and ionization history of the universe must leave its imprint on the Cosmic Microwave Background (CMB) through resonance scattering of the CMB photons in various atomic, ionic and molecular lines. These scattering events partially erase the primordial temperature fluctuation pattern, but also produce new fluctuations because of the motion of the scatterer. Due to the frequency dependent nature of the scattering, it will be possible to extract signals of very low amplitude by comparing sky-maps obtained from different observing channels with different frequencies. Present and future CMB experiments, both space- and ground-based, with their tremendous sensitivity level promises to place very interesting upper limits on the amount of heavy metals present in low-density optically thin regions throughout the universe – illuminating the epoch of metal enrichment by the very first stars at the end of the cosmic Dark Ages.

	Main Colloquium
Dr. Jürgen Röttger	ORATED

Institute of Space Sciences, National Central University, Taiwan & Max-Planck-Institut für Aeronomie, Lindau

EISCAT stands for European Incoherent Scatter Scientific Association. It was established more than 25 years ago for studies of the Earth’s ionosphere and upper atmosphere in polar regions. The EISCAT observatories, located in northern Scandinavia and on Spitzbergen/Svalbard, operate high power radars with high-gain dish antennas and sophisticated digital radar control, data acquisition and analysis systems. After a brief description of the incoherent scatter process from the ionospheric plasma and of some research highlights, particular details of antenna and receiver design will be discussed. In this context the EISCAT Svalbard Radar project will be described, which was a major innovative endeavour of the association in the 1990s. The ionosphere is a highly dispersive medium for electromagnetic waves in the frequency ranges (10-300 MHz) to be used in the new project LOFAR (Low Frequency Array), which is a high resolution interferometer for radio astronomy and ionospheric research. The potential disturbance of such measurements due to ray bending, phase and group path delays, Faraday rotation, absorption and phase and amplitude scintillations will be summarized and possible solutions for corrections will be finally discussed.

	Main Colloquium
Dr. Wolfram Freudling	ORATED

European Southern Observatory, Garching

Observations of QSOs at a redshift of 6 and above probe the Universe when it was less than a billion years old. The spectral properties of these objects are remarkable similar to those at lower redshifts. This lack of evolution is in particular surprising for elements such as iron, for which predicted production times scales in supernovae of type Ia are on the order of several 100 million years. The talk will present new observations of iron in zsim6 QSOs and discuss different formation scenarios.

	Special Colloquium
Dr. Roopesh Ojha	ORATED

Australia Telescope National Facility, Epping, NSW, Australia

As part of an ongoing collaboration between the U.S. Naval Observatory (USNO) and the Australia Telescope National Facility (ATNF) a sample of 184 quasars located south of -20 degrees have been observed at 8.4 GHz using the Australian Long Baseline Array (LBA) augmented by telescopes in South Africa and Hawaii. This is the largest sample of southern quasars ever imaged with VLBI at this frequency and along with some well known objects contains many sources that have never before been observed at milliarcsecond resolution. After an introduction to this project, I will present results, discuss existing problems and present a possible solution that may be of interest to the European VLBI Network.

	Special Colloquium
Dr. Robert Ivison	ORATED

Royal Observatory, Edinburgh, UK

Major advances have been made in our understanding of galaxy formation and dusty galaxies in 1997. SCUBA galaxies, named after the innovative camera with which they were first seen, are often responsible for 5Jy-level radio emission; thus pinpointed, they are usually found to be faint, morphologically disturbed and red, or multi-hued, as expected for a distant, dust-reddened population. I will describe recent advances, including the measurement of a representative spectroscopic redshift distribution, the resolution of the entire submm background by exploiting gravitational lensing, the detection of X-ray and mid-IR emission from a significant fraction of the population, the detection of colossal quantities of molecular gas, and the first tangible indications of the clustering of these massive galaxies.

	Special Colloquium
Prof. Dr. Heino Falcke	ORATED

ASTRON

Radio astronomy is experiencing a rapid revival with major new instrumentation being developed. The frontiers of this movement are at the high- and low-frequency end of the radio spectrum: The submm-wave telescope ALMA will revolutionize high-frequency radio astronomy and offer new insight into the dark universe, while LOFAR and later the Square Kilometer Array promise a hundredfold increase in sensitivity and resolution at meter-waves. Scientific applications are manifold and, after introducing the telescopes, I pick out a few examples from my personal research which highlight the wide range of possibilities radio astronomy offers to address fundamental physical questions. High frequencies in principle also achieve the highest resolution and allow one to probe deep into the most compact regions of the universe. Millimeter- and and submm-wave polarimetry, for example, probe the hot and turbulent plasma in the immediate vicinity of black holes and for the first time start to seriously constrain models of black hole accretion. In fact, long baseline interferometry with submm-telescopes will even allow one to directly image the black hole event horizon and thus prove its existence. At low frequencies, on the other hand, a software telescope like LOFAR, which consists essentially of one of the fastest super computers available today, offers a unique flexibility. Digital beam steering, for example, makes detection of the highest energy cosmic particles possible, while mutli-beaming facilitates large surveys that will unveil the cosmologically important “Epoch of Reionization”. More than ever, radio astronomy is at the very forefront of the current technological and scientific development.

	Special Colloquium
Dr. Robert Braun	ORATED

ASTRON

Radio astronomy continues to play a pivotal role in addressing fundamental questions of astrophysics. Questions of cosmology, in particular, have a broad appeal since we are all concerned at some level with issues such as: How did the universe originate; how did it evolve into it’s current state; and how will it continue to evolve? In this talk, we will consider some recent progress in addressing some of these issues. First, we’ll focus on the process of galaxy assembly. Models of hierarchical galaxy formation within the currently favored LCDM framework predict vast numbers of low mass satellites surrounding the larger galaxies. Their predicted numbers exceed what has been observed by more than an order of magnitude, leading to the so-called “Missing Low Mass Companion” problem. In the past months it has been possible to detect this population of extremely dark-matter dominated, low-mass companions for the first time. These objects are too feeble to have an associated stellar component, but can be traced by small amounts of gravitationally bound neutral hydrogen. Second, we’ll consider the universal baryon distribution. Current theory suggests that only some 30makes up a low density “Cosmic Web” of filaments between the galaxies. While dominating the universal baryon budget, this component has proved extremely elusive to direct study. In the past months we have succeeded in direct imaging of this Cosmic Web. Despite the fact that this component is largely ionized, there is a small neutral fraction that permits it’s kinematic detection in the 21cm line of neutral hydrogen. Finally, we will consider the exciting possibilities afforded by the next generation of radio telescopes which are now being realized: ALMA, SKA, and LOFAR to illuminate (1) the star formation history of the universe, (2) the imprint of acoustic oscillations on large-scale structure and (3) the epoch of re-ionization.

	Special Colloquium
Dr. Frank Bertoldi	ORATED

MPIfR

The distant Universe has recently been explored with bolometer and coherent receivers on ground-based, balloon-borne, and space telescopes, resulting in impressive constraints on the geometry of cosmic space, and on the formation history of galaxies, stars, and massive black holes. Much has been learned - still more awaits discovery. I will review the state of observational “millimeter-cosmology” and examine some prospects for major progress in the years to come.

	Special Colloquium
Priv.-Doz. Dr. Rainer Mauersberger	ORATED

IRAM, Observatorio de Pico Veleta, Spain

Physical and chemical properties of molecular clouds in the central regions of galaxies differ from those in galactic disks. In the past decade high resolution observations of molecules with high dipole moments have been made possible and offer powerful tools to determine the physical properties of the circumnuclear gas (such as densities and temperatures, heating mechanisms), its chemical composition and underlying physical reasons (e.g. shocks, UV irradiation). Finally the relative abundances of isotopes of C, O and S are important indicators of the past nucleochemical evolution of the gas.

	Special Colloquium
Dr. Peter Schilke	ORATED

MPIfR

High Mass Stars influence the interstellar medium in Galaxies tremendously, through input of radiative and mechanical energy, in the form of stellar winds, UV radiation, and ultimately supernova explosions. They shape the destiny of molecular clouds, and regulate star formation. In the life of a galaxy, they are particularly important in starburst or merger phases. Therefore, they provide most of the energy powering ultraluminous galaxies, also and especially in the early universe. In spite of all this, surprisingly little is known about the formation of high mass stars. In this talk, I will review the state of the art, both observationally and theoretically, and will present some strategies for future research. The most important contribution in the next decades is expected by observations with the ALMA interferometer, but also space missions such as Herschel will play a major role.

	Special Colloquium
Dr. Rob Swaters	ORATED

Department of Physics and Astronomy, John Hopkins University, Baltimore, USA

The most dominant mass component of galaxies is also the one that least is known about: dark matter. Because it is the dominant mass component, this lack of knowledge of the dark matter in galaxies hampers a thorough understanding of the formation and evolution of galaxies. In my presentation, I will discuss recent work on dark matter in disk galaxies, based on kinematical data obtained from HI and H-alpha emission line observations and stellar absorption line observations, and focus on the implications for galaxy formation models. I will also discuss ongoing and future observations which will make possible an accurate measurement of the mass structure of disk galaxies, and, by doing this at various redshifts, make possible a direct measurement of both the luminosity and mass evolution of disk galaxies.

	Main Colloquium
Multiple Speakers: Check abstract for details	ORATED

Speaker: J. Lequeux / E. Churchwell / D. Downes / J. Baars / M. Grewing / H.-P. Röser / K.M. Menten / R. Genzel Affiliation: LERMA, Obs. de Paris / Univ. Wisconsin-Madison / IRAM-Grenoble / Univ. Massachusetts, Amherst / IRAM-Grenoble / MPIfR / MPIfR / MPIeP, Garching

	Special Colloquium
Claudia Brüns	ORATED

Uni-Bonn

TBA

	Special Colloquium
Corinna Karow	ORATED

MPIfR

TBA

	Special Colloquium
Tim Schrabback	ORATED

IAEF, Uni-Bonn

TBA

	Special Colloquium
Dr. Robert E. Smith	ORATED

University of Nottingham

TBA

	Main Colloquium
Prof. Dr. Wolfram Kollatschny	ORATED

Universitäts-Sternwarte Göttingen

In my talk I will review some key aspects of the central line emitting regions in AGN, the narrow line region and the broad line region. Continuum and emission line variability provides a powerful tool to map the structure and kinematics of the central broad line region. Observed delays of the order of days for the intensities and line profiles probe regions only microarcseconds from the nucleus. I will concentrate on observations taken in the optical wavelength region. Finally, I will discuss different methods to derive the mass of the central supermassive black holes from spectral variability.

	Special Colloquium
Dr. Lister Staveley-Smith	ORATED

Australia Telescope National Facility

TBA

	Main Colloquium
Dr. Ralf Klessen	ORATED

Astrophysikalisches Institut Postdam

Stars form by gravoturbulent fragmentation of interstellar gas clouds. The supersonic turbulence ubiquitously observed in molecular gas generates strong density fluctuations with gravity taking over in the densest and most massive regions. Once gas clumps become gravitationally unstable, collapse sets in and the central density increases until a protostellar object forms and grows in mass via accretion from the infalling envelope. Turbulence plays a dual role. On global scales it provides support, while at the same time it can promote local collapse. Stellar birth is thus intimately linked to the dynamical behavior of parental gas cloud, which determines when and where protostellar cores form, and how they contract and grow in mass via accretion from the surrounding cloud material to build up stars. Slow, inefficient, isolated star formation is a hallmark of turbulent support, whereas fast, efficient, clustered star formation occurs in its absence. I will review the current progress in star formation theory and discuss results from numerical calculations of gravoturbulent cloud fragmentation. Special emphasis lies on the complex dynamical evolution of nascent star clusters, on the mass growth history of individual protostars, and on the resulting mass spectrum of stars, the IMF. The equation of state (EOS) plays a pivotal role in the fragmentation process. Under typical cloud conditions, massive stars form as part of dense clusters. However, for gas with effective polytropic index greater than unity star formation becomes biased towards isolated massive stars, which may be of relevance for understanding Pop III stars.

	Main Colloquium
Prof. Dr. Michael Kramer	ORATED

MPIfR

In this talk I will briefly review the applications of pulsars in a wide range of physical and astrophysical problems. This allows me to demonstrate that our recent discovery of the first double pulsar provides a unique laboratory for gravitational physics and plasma physics. I will conclude by presenting the “Level-0” science case for pulsars and the SKA which focuses on strong-field tests of gravity using black holes and the detection of a gravitational wave background.

	Special Colloquium
Michael Berger	ORATED

MPIfR

TBA

	Main Colloquium
Dr. Martin Hardcastle	ORATED

Bristol University

I shall argue that X-ray synchrotron radiation from radio galaxies and quasars is a key diagnostic of particle acceleration in those systems, telling us where the bulk kinetic energy of the jets is converted to the random energy of ultra-relativistic electrons. I shall show that low-power radio galaxies offer the most convincing detection of X-ray synchrotron radiation, and show how particle acceleration can be related to jet fluid dynamics in the nearest active galaxy, Centaurus A. Finally, I shall present some evidence that an X-ray synchrotron model may be applicable in the hotspots of many powerful classical double radio galaxies, and discuss the implications for our understanding of the physical conditions in those systems.

	Special Colloquium
Anja von der Linden	ORATED

IAEF, Uni-Bonn

TBA

	Main Colloquium
Prof. Dr. Richard Wielebinski	ORATED

MPIfR

The first detection of radio polarization was announced almost simultaneously from Cambridge and Leiden in 1962. This was also the final proof that it was synchrotron emission (relativistic electrons emitting radio waves in magnetic fields) that we were o bserving from our Galaxy. Surveys of radio polarization that followed gave us first information about the structure of the magnetic fields in the Milky Way. In particular Faraday rotation was detected and used to give us information about magnetic fields in the line of sight. In the 1970s observations of radio polarization in external galaxies were made giving us new information about magnetic fields in these objects. The Effelsberg radio telescope was at the forefront of these discoveries. Magnetic fiel ds were also detected in radio galaxies and clusters of galaxies. Pulsars and extragalactic radio sources were also used as probes of the Galactic magnetic field. More recently a ’return’ to the Galaxy has been made with detailed information about small-s cale magnetic fields. Polarization mapping and the Faraday effect give us new information about the turbulent Magnetic Interstellar Medium.

	Special Colloquium
Prof. José-María Torrelles	ORATED

Institut d'Estudis Espacials de Catalunya-CSIC, Barcelona, Spain

We know that Herbig-Haro objects, jets, molecular outflows, and masers are all signatures of the mass-ejection phase related with the first steps of evolution of young stellar objects. According to theory, all these phenomena require the formation of a ``disk-YSO-outflow“ system and its subsequent interaction with the ambient medium to account for the observed properties. However, our further knowledge of the evolution of protostars has been hampered by the lack of data at the scales of a few astronomical units, where relevant physical phenomena are expected to occur. In the last few years, a new way to study these star-forming regions through VLBI measurements of proper motions of water masers has emerged. I will review recent proper motion studies toward low, intermediate, and high-mass stars. These observations are just starting to reveal exciting perspectives, such as measuring the full motions of the gas within the circumstellar disk/outflows at scales of AU, discovering new phenomena (e.g., isotropic mass ejections, discovery of water maser ``micro-structures” exhibiting remarkable coherent and well ordered spatio-kinematical behavior at the very small scales of 1 AU), opening new, still puzzling questions in early stellar evolution.

	Special Colloquium
Dr. Roberto Maiolino	ORATED

Osservatorio Astrofisico di Arcetri, Florence, Italy

There is growing evidence for a co-evolution of quasar activity (tracing accretion onto a supermassive black) and star formation in their host galaxies. The most distant quasars known at zsim5–6 offer the possibility of investigating this co-evolution in the early universe, at an epoch close to the re-ionization. Moreover, quasars can be used as powerful candles to investigate the physical and chemical evolution of the circumnuclear gas, which is in turn tightly associated with the stellar evolution. I will present the results of a campaign of infrared spectroscopic observations of the most distant quasars aimed at investigating the properties of their circumnuclear gas and the implications for the star formation in their host galaxies. In particular we derive the evolution of the iron enrichment as a function of redshift up to z=6 and I will discuss the possible implications for the star formation history at z>6. I will then show that the properties of the circumnuclear gas in the most distant quasars are different (more extreme in terms of density an dynamics) than observed in quasars at lower redshift (z<4); I will discuss the possibility that such extreme properties are associated with the early stages of the star formation in the circumnuclear region. Finally I will show evidences that the properties of dust at zsim6 are significantly different than observed at lower redshift, and discuss the implications on the origin of such dust grains at very high redshift.

	Main Colloquium
Prof. Dr. Jens Niemeyer	ORATED

Institut für Theoretische Physik und Astrophysik, Universität Würzburg

Type Ia supernovae (SNe Ia) are excellent cosmological distance indicators but the explosion physics is still far from being fully understood. The standard explosion model for SNe Ia is the thermonuclear disruption of a Chandrasekhar mass white dwarf composed of carbon and oxygen. While the nuclear reactions are confined to a “flame” less than a millimeter thick, the explosion produces turbulent structures as large as several thousand kilometers. I will discuss the relevant physics at each length scale and present recent results of three-dimensional SN Ia simulations.

	Special Colloquium
Dr. Ruben R. Andreasyan	ORATED

Byurakan Astroph. Obs., Armenia

We studied the Fanaroff-Riley (FR) dichotomy of extragalactic radio sources by means of their optical and radio morphology. Our sample comprises of 267 nearby radio galaxies and 280 extragalactic radio sources. It was shown that there are significant differences (i) in the relative orientations between the optical and radio axes of nearby radio galaxies, (ii) in the ellipticities of optical host galaxies of FRI/FRII radio sources. The position angles between the integrated intrinsic radio polarization and the major axes are also found to be different. We suggest a simple classification of extragalactic radio sources in terms of elongation of the radio image, which correlates to some extent with the Fanaroff-Riley types.

	Special Colloquium
Maren Eberhardt	ORATED

MPIfR

TBA

	Main Colloquium
Prof. Dr. Stefan Dreizler	ORATED

Universitäts-Sternwarte Göttingen

Late phases of stellar evolution are crutial for the cosmic circuit of matter because the yield of nuclear processed material is determined during this stage. Our understanding requires stellar spectroscopy as the basis for our understanding the physical properties of stars, stellar atmosphere models for the analysis of the spectra and stellar evolution models to connect the evolutionary stages of the individual objects to an evolution scenario. I will present our non-LTE model atmosphere modeling and its application to hot white dwarfs in the context of evolution of low and intermediate mass stars.

	Main Colloquium
Dr. Thomas Boller	ORATED

Max-Planck-Institut für extraterrestrische Physik, Garching

Recent X-ray observations of active galaxies and quasars have significantly improved our ability to probe the environments of supermassive black holes. The high throughput and excellent spectral capabilities of the new generation of X-ray observatories have already revealed many new and unexpected observational results, resulting in a more precise understanding of the physics operating within a few Schwarzschild radii around the supermassive black hole, the molecular torus zone as well as the nuclear starburst activity. The talk will review the new observational results on the iron K line as an important diagnostic tool for probing matter within a few Schwarzschild radii. It appears that most of the sources may now be better described by pure continuum absorption and narrow high equivalent width iron K line emission seen in reflection from the molecular torus. In most cases we have lost the scattering at the relativistic accretion disk. We are also beginning to discover sources with sudden drops in flux at rest-frame energies above 7 keV, without any detectable narrow Fe K line emission. The energy of these features suggests a connection with the neutral or ionized Fe K photoelectric edge and the lack of any obvious Fe K reemission points to the presence of nearly neutral, high density cold gas that accompanies the active regions above an accretion disk. It is possible that the model we have developed has a wider relevance for Seyfert galaxies and extends beyond the standard models. I will also describe how these studies are laying crucial observational groundwork for the next generation of X-ray space telescopes.

	Special Colloquium
Dr. Almudena Prieto	ORATED

Max-Planck-Institut für Astronomie, Heidelberg

The use of adaptive optics and interferometer techniques in the IR has proven to be extremely powerful in penetrating and resolving the central parsecs of the brightest galaxies. Two main results that have emerged from the study of the nearest active galactic nuclei using those techniques will be reviewed: 1) Within scales of a few parsecs, some AGN show with unprecedented detail nuclear channels through which material seems to be driven towards the very centre, others however show a “clean” central environment. At the very center, a compact region of about 2 pc size is resolved in the best studied cases, for most cases the spatial scales achived limit the nuclear torus to less than 10 pc in size, 2) Sub-arcsec spectral energy distributions of these cores, spanning the UV - radio range, show very different from those currently in use and based on larger aperture data: the shape of the spectral energy distribution is different and the bolometric luminosity largely overestimated. The implications from these differences will be discussed.

	Special Colloquium
Dipl.-Ing. Alexander von Buelow	ORATED

Institute for Real-Time Computersystems, Technische Universität Muenchen

TBA

	Main Colloquium
Prof. Michael G. Burton	ORATED

University of New South Wales, Sydney, Australia

The high Antarctic plateau provides a unique environment on the Earth, one well suited for a range of astronomical applications. Over 3,000m high and more than two thousand kilometres across, as well as being almost perfectly flat on top. The winter time temperature drops to near -90C, and water vapour columns to less than 250um ppt/H2O. Less appreciated is that there is hardly any wind on its summits, for this is where the katabatic winds, which produce the ferocious coastal storms, begin as a trickle. It has been appreciated for some time that these characteristics provide superlative conditions for infrared and sub-millimetre astronomy, as a number of facilities at the South Pole can now testify too. For the cold reduces infrared sky backgrounds by between one and two orders of magnitude from temperate sites, and the dry air opens new windows to see through. Less appreciated is that the seeing is generated almost entirely in a narrow surface boundary layer, rather than at high altitude. This dramatically alters the conditions under which AO systems operate, both greatly increasing the isoplanatic angle and coherence times. The French-Italian Concordia Station, at Dome C on one of the summits of the Antarctic plateau, is now nearing completion, and the first winter-time measurements of site conditions have been made there by the AASTINO (Automated Astrophysical Site Testing INternational Observatory). Dome C might provide the optimum location on the Earth for the construction of some kinds of future large telescopes, operating at infrared and/or sub-millimetre wavelengths. This talk will provide an introduction to Antarctic astronomy, describing some of the activities on the continent, as the South Pole and Dome C have been characterised for astronomy over the past decade, as well as presenting some of the science that has been obtained. For further information please see the South Pole Diaries at http://www.phys.unsw.edu.au/southpolediaries/

	Special Colloquium
Dr. Simona Mei	ORATED

ESO & Johns Hopkins University

The impact of future Sunyaev-Zel’dovich cluster surveys on the constraints on the cosmological parameters and the understanding of cluster physics will be discussed. In particular, predictions for the future APEX SZ survey will be shown.

	Main Colloquium
Rainer Schödel	ORATED

Universität-Köln

The new sensitive, high-resolution techniques in radio, X-ray, and near-infrared (NIR) astronomy have lead to an enormous boom in galactic centre (GC) research in the past years, with new results being published almost on a weekly basis. The non-thermal radio, X-ray, and NIR source SagittariusA^* (SgrA^*), located at the dynamical centre of the GC stellar cluster, has recently become the most ironclad case for a super-massive black hole. The GC can thus be regarded as an exemplary model for a quiescent galaxy nucleus. We will review the most recent results of GC research from the viewpoint of NIR astronomy. NIR radiation allows to monitor the nuclear star cluster and its dynamics and probes a radiation window that is vital for constraining models of accretion and emission of matter near SgrA^*. The measurement of individual stellar orbits around SgrA^* allows to determine its mass, location, and distance with high precision. The nuclear stellar cluster displays a density cusp centred on the black hole, , with stellar number densities reaching as high as several times 10^8 stars pc^{-3}. The presence of young, dynamically unrelaxed stars shows that the nuclear cluster is highly dynamic and continuously evolving. Most surprisingly, young O/B-type stars are found in the immediate vicinity of the black hole. Currently, there is no model that can explain the presence of these stars satisfactorily. Most recently, a NIR counterpart of SgrA^* has finally been detected ith the aid of adaptive optics instrumentation at the ESO VLT and the Keck telescopes. The NIR counterpart of SgrA^* is faint (less than 5mJy at 2 microns), but highly variable and displays flares, where the emission rises by factors of one to ten several times per day. The short rise-and-fall time scales of these flares show that they must occur within less than ten Schwarzschild radii of the black hole. Most intrigingly, the flares appear to display quasi-periodic sub-peaks. The short time scale of this periodicity could be due to Doppler boosting of accreted material near the last-stable-orbit, opening thus the possibility, for the first time, to measure the spin of a black hole.

	Special Colloquium
Dominik Riechers	ORATED

MPIfR

I will present a study of the kinematics, star formation and cold gas properties of the highest redshift, most intensely star-forming galaxies with the (Expanded) Very Large Array, the Plateau de Bure Interferometer, and CARMA. Such detailed investigations are vital for our understanding of the formation and evolution of massive galaxies in the early universe. Molecular gas is the prerequisite material for star formation to occur. Also, gas dynamics can be used to trace the gravitational potential of galaxies, and thus, to obtain an independent estimate of the total mass in their central few kiloparsecs. Measuring the gas fraction is important to determine the evolutionary state of a galaxy, and to constrain gas depletion timescales and starburst lifetimes. The morphology and kinematics of the cold gas can also provide direct insight on the dominant mechanism responsible for the stellar buildup of these systems (i.e., major mergers vs. secular evolution). Determining the stellar and total mass of distant galaxies is important to investigate whether or not the (in the nearby universe) linear relation between stellar mass and black hole mass in early-type galaxies evolves with cosmic time and/or toward the high mass end. Such studies thus set the pace for future investigations of star formation and galaxy assembly out to the first galaxies that form in the universe, which will facilitate the capabilities of the upcoming Atacama Large (sub-)Millimeter Array (ALMA).

	Special Colloquium
Dr. Markus Behnke	ORATED

Dept. Physics, Ohio State University

Rotational spectrometers are typically limited by narrow bandwidth, long data acquisition times or substantial complexity. Recording the complex spectral patterns of asymmetric rotors or less stable species in mixtures of several compounds is quite time consuming and challenging with these systems. The Fast Scan Submillimeter Spectroscopy Technique (FASSST) presented here overcomes these limitations. It is a high resolution spectroscopic system for the mm/sub-mm spectral region (100 - 1000 GHz) which is fast, broadband, sensitive and simple. An overview of the FASSST systems key features and recent developments will be given. The capabilities of FASSST will be illustrated by discussing several recent experiments. These include the spectroscopy on the pre-biotic molecule oxiranecarbonitrile, on complex gas mixtures and studies on the intermediates of high temperature sulfoxide chemistry.

	Main Colloquium
Dr. Frank Bertoldi	ORATED

MPIfR

By detecting thermal emission from dusty star forming regions, bolometer array cameras have opened a window on star formation in the earliest galaxies. Up to half the stars in the Universe apparently formed in luminous infrared galaxies, which are inconspicuous at optical wavelengths, and which challenge current galaxy formation models. Bolometer cameras and follow-up line observations are revealing star formation also in distant quasars, establishing a close connection between the formation of stars and massive black holes, and a rapid enrichment of the interstellar medium in the earliest collapsed structures, way into the “dark ages”. Through large-scale surveys of the Sunyaev-Zel’dovich effect of galaxy clusters, bolometer arrays will soon follow the formation history of the largest and latest collapsed structures, helping thereby also to constrain basic cosmological parameters.

	Special Colloquium
Dr. Jens Wendler	ORATED

Fachbereich Geowissenschaften, Universität Bremen

The Earth’s liquid outer core is characterized by current flows which facilitate the generation and maintenance of the geomagnetic field. This field shields the planet from cosmic particles and radiation. During the times when the geomagnetic field revers es its poles, the shielding is significantly lower. Then cosmic radiation can enter the atmosphere at increased levels. This has implications on the atmospheric physics particularly the cloud formation and therefore it can trigger climatic changes. As a v ery simplified model, more clouds increase the Earth’s reflectivity and thus may have the potential of cooling the planet. A second factor which modulates the cosmic ray flux is the heliospheric interplanetary magnetic field. As a third factor, recent models of the solar system4s motion through the Milky Way Galaxy indicate a variable intrinsic cosmic ray flux. These variations in cosmic ray flux apparently caused the Earth’s climate system to switch between a ``warm mode“ and a ``cold mode” at a frequency of about 150-180 Million years. ``Warm modes“ occurred during times when the solar system was traveling between the optic spiral arms of our galaxy. Interestingly, the Earth’s magnetic field also repeatedly switches between two modes, a ``reversing mode” (frequent polarity reversals) and a ``superchron mode" (tens of Million years long phases of non-reversal) at a similar period. Between the optic spiral arms Earth experienced geomagnetic superchrons, for example during the Creta ceous age. This raises three major questions: Is there a causal relationship between the magnetic field modes and the climate modes?; Does the galaxy control the Earth’s magnetic field?; and: Does even the Sun experience different externally-forced magnet ic activity modes? In order to evaluate these fundamental questions I aim at initiating an Astrophysics-Geology-Climatology working group.