Main Colloquium
Dr. Rosa A. Gonzalez-Lopezlira	ORATED

Centro de Radioastronomia y Astrofisica, CRyA-UNAM, Morelia, Mexico

Azimuthal color (age) gradients across spiral arms are one of the main predictions of density wave theory; gradients are the result of star-formation triggering by the spiral waves. In a sample of 13 non-barred (types A and AB) and 11 barred (B) spiral galaxies, we find that 10 non-barred and all barred galaxies present regions that match the theoretical predictions. By comparing the observed gradients with stellar population synthesis models, the pattern speed and the location of major resonances have been determined. The resonance positions indicate that 9 of the non-barred galaxies have spiral arms that extend to the outer Lindblad resonance (OLR), while in one the spiral arms reach the corotation radius. As for the barred galaxies, the bars end at their own corotation. Of the 9 barred galaxies with gradients in both bars and spirals, 6 (67%) appear to have a bar and a spiral with similar pattern speeds, while 3 (33%) do not. These 3 objects are all later Hubble types, whereas 5 out of the 6 galaxies where bars and spiral arms share a pattern speed are early Hubble types. Notably, and further confirming the link between gradients and dynamics, the effects of non-circular stellar velocities are clearly discerned in the data.

	Main Colloquium
Prof. Pavel Kroupa	ORATED

Universität Bonn

Ultra compact dwarf galaxies (UCDs) show a larger M/L than star clusters but are collisionless. The high M/L values may be a result of a top-heavy IMF contributing remnants in large numbers. Also, some globular clusters show evidence for an abnormally depleted low-mass stellar mass function. This may be due to significant mass loss from a top-heavy IMF in an initially mass segregated cluster. These scenarios allow us (with Joerg Dabringhausen and Michael Marks) to distill a possible systematically varying IMF top-heaviness with star-burst density.

	Main Colloquium
Dr. Elvire de Beck	ORATED

MPIfR

The carbon-rich star IRC+10216 is known as a “prototypical” Asymptotic Giant Branch (AGB) star. It has been showcased many times, since it is located very nearby, and it holds a treasure when it comes to molecular chemistry. It is, however, not all that easy to get a grip on this all-time favourite. It continuously forces us to confront modelling issues, with the gaps in our knowledge about the AGB physics and chemistry, and with the ever present lack of data. The Herschel satellite, launched in May 2009, however, comes to the rescue. Combining the new, high-quality Herschel data with the data coverage of the last decades gives us the opportunity to sketch a more complete picture. I will focus on the detection of warm water vapour in the envelope of this star, on the measurement of many HCN lines, and on the modelling of one of the smallest carbon chain radicals, CCH.

	Main Colloquium
Dr. Rainer Spurzem	ORATED

ARI, Heidelberg

We study the dynamical evolution of dense star clusters (globular clusters and galactic nuclei with single and binary supermassive black holes). Rotation accelerates the collisional dynamics of the system, and if Post-Newtonian relativistic forces between black holes are included, SMBH coalescence and gravitational wave emission is triggered without any stalling problem for the last parsec after galaxy mergers. The treatment of relativistic corrections to Newtonian gravity is reviewed and we discuss gravitational wave emission in pulsar timing and LISA bands, In the second part of the talk our new computational instruments are presented. New powerful supercomputers have been built using graphical processing units (GPU) for general purpose computing. China has just obtained the top rank in the list of the fastest supercomputers in the world with a GPU based system, and holds further ranks in the top 20 (all with GPU clusters). The research of Chinese Academy of Sciences and National Astronnomical Observatory with such GPU clusters will be reviewed, present and future applications in computer simulation and data processing discussed. GPU and other ’green’ supercomputing hardware is one stepping stone on the path to reach Exascale supercomputing.

	Main Colloquium
Dr. Rosie Chen	ORATED

MPIfR

Recent Spitzer mid-IR observations have revealed a large number of individually resolved massive young stellar objects (YSOs) in the Magellanic clouds, providing an excellent opportunity to study massive star formation with metallicity and galactic environment different from the Galaxy. Using Spitzer IRAC/MIPS data from the SAGE survey and complementary high-resolution ground-based optical/near-IR data, we have identified YSOs in HII complexes in the Large Magellanic Cloud (LMC) and a large area in the Magellanic Bridge. These two systems span a metallicity range of 1/3-1/8 Zo, and different galactic environments with star formation modes from mainly self-propagating in the LMC to tidally disrupted in the Bridge. We have modeled spectral energy distributions of the YSOs and found that they have masses ranging from 4 to 45 Mo in the LMC, while the most massive ones in the Bridge are  10 Mo. YSOs in these two systems are found to span a wide range of evolutionary stages from highly embedded to surrounded by remnant material. Using surveys in H-alpha, CO, and HI of these two systems, we further investigate the causal relationship between gas and stars. The dependence of star formation on local environment will be discussed by examining individual regions within the LMC and the Bridge. The dependence of star formation on metallicity and galactic environment will be assessed by comparing these two systems.

	Main Colloquium
Dr. Genevieve Parmentier	ORATED

Astronomisches Rechen-Institut, Heidelberg

In the Local Universe, a significant fraction of the stars are observed to form in gas-embedded clusters. The exciting prospect has therefore arisen that star cluster systems can trace the star formation histories of their host galaxies, provided we get a firm handle on cluster dissolution mechanisms. Cluster mass-losses sensitively depend on cluster-formation and cluster environmental conditions. I will demonstrate how the study of star cluster system properties enables us to get powerful insights into those conditions, thereby positioning star clusters at a crossroad between star formation and galaxy evolution. Focusing on the cluster mass function, I will highlight how we can probe into the properties of cluster-forming molecular clumps. In particular, the study of the tidal field impact upon young star clusters dynamically responding to the expulsion of their residual star-forming gas sheds light on the mass-radius relation of cluster-forming clumps, namely, a mass-radius relation of constant volume density is preferred to one of constant surface density. I will also show how furthering this argument allows to understand why the star cluster mass function is steeper than the molecular cloud mass function.

	Main Colloquium
Dr. Loren Anderson	ORATED

Observatoire Astronomique de Marseille Provence

The Green Bank Telescope HII region discovery survey (GBT HRDS) has doubled the number of HII regions with measured radio recombination line (RRL) emission over the zone l = 65-343, |b| < 1. By leveraging the sensitivity of the 100-m GBT at X-band (9 GHz, 3 cm), we have detected 603 RRL components from 448 newly identified HII regions. Our targets were selected based on spatially coincident 24 µm and 21 cm continuum emission, a criterion that is a strong indication of thermal emission. The RRL velocities of 25 HRDS sources place them in the Outer Arm of the Galaxy where previously only two HII regions were known. By resolving the kinematic distance ambiguity using HI absorption studies, we have computed kinematic distances for nearly 200 sources. The locations of the HRDS sources show clear signs of Galactic structure suggestive of spiral arms with mean radii of 4.5 and 6 kpc. The most distant detected sources lie above the Galactic plane and show excellent agreement with the Galactic warp and flaring observed in CO and HI. We detected over 200 regions that have a bubble morphology and further find that approximately half of all Galactic HII regions have such a morphology. Bubble HII regions have been shown to be ideal locations to study triggered star formation. I will discuss the current understanding of triggered star formation and recent work from Herschel attempting to quantify the efficiency of this star formation mode.

	Main Colloquium
Dr. Jelle de Plaa	ORATED

SRON/ Netherlands Institute for Space Research

The hot X-ray emitting gas in clusters of galaxies has been continuously enriched with metals during its evolution. The current generation of X-ray telescopes, like XMM-Newton and Suzaku, enable us to measure the abundances of the most abundant metals in clusters with a high accuracy and provide information about their spatial distribution. This provides an opportunity to test chemical enrichment models and models of supernova explosions. The presentation will focus on recent results from XMM-Newton and the implications for our knowledge about the chemical enrichment in clusters of galaxies.

	Main Colloquium
Dr. Claudio Codella	ORATED

INAF - Osservatorio Astrofisico de Arcetri, Italy

We present the first results of the spectral survey of the bow-shock B1 in the chemically active outflow driven by the Class 0 protostar L1157-mm. The observations are part of the CHESS GT Herschel Key Program, and were obtained with HIFI and PACS. The bright blue-shifted bow shock B1 is the ideal laboratory for studying the link between the hot (1000-2000 K) component traced by H2 IR-emission and the cold (10-20 K) swept-up material. The main aim is to trace the warm gas chemically enriched by the passage of a shock and to infer the excitation conditions in L1157-B1. For the first time, we detected high-excitation (up to Eu around 200 K) emission lines of species whose abundance is largely enhanced in shocked regions. This has allowed us to trace with these species the existence of a high excitation regime with Tkin higher than about 200-300 K. The comparison between the profiles due to molecules released from dust mantles (NH3, H2CO, CH3OH) with that for water is consistent with the scenario where water is also formed in the gas phase in high-temperature regions, where sputtering or grain-grain collisions are not efficient.

	Main Colloquium
Dr. Ana Sepulcre	ORATED

INAF - Osservatorio Astrofisico de Arcetri, Italy

Recent theories predict that OB stars may form only above a minimum surface density of the parental molecular clump. With this in mind, we have searched for high-mass star formation signposts, mainly in the form of infall and outflows, in a sample of 48 massive molecular clumps (M > 100 Msun), including both IR-dark and IR-loud sources and covering a wide range of surface densities. The aim was to look for evolutionary trends and test observationally the above mentioned theoretical prediction. Each of these sources has been mapped in the HCO+(1-0), HCN(1-0), and C18O(2-1) lines with the IRAM-30m telescope in Pico Veleta (Spain). Molecular outflows are detected in 75Remarkably, we measure a surface density threshold of 0.3 g/cm2 above which the detection rate becomes 100more massive, lending support to the theoretical prediction. Subsequent observations in the SiO(2-1) and (3-2) transitions suggest that the jet/outflow phase is more active in the earliest stages of stellar formation, and that these lose power and likely de-collimate as time evolves. The infall detection rate measured in our sample is low, but significantly higher in the IR-dark sub-sample, an indication that these objects could be associated with the onset of star formation.

	Main Colloquium
Dr. Rumpa Choudbury	ORATED

Indian Institute of Astrophysics, Bangalore, India

TBA

	Main Colloquium
Dr. Tim Koslowski	ORATED

Perimeter Institute for Theoretical Physics, Ontario, Canada

General Relativity and Quantum Field Theories are fundamental building blocks of our current understanding of the universe for more than 60 years, their unification to a theory of Quantum Gravity has not been achieved yet. This lead to many speculative theories, most prominently string theory. I this colloquium I will introduce explain the problem of Quantum Gravity and how it is addressed in Loop Quantum Gravity, which is an “alternative” approach to Quantum Gravity. To underline that Loop Quantum Gravity is not a finished program, I will also explain some other currently investigated approaches to Quantum Gravity and discuss their strengths and weaknesses.

	Main Colloquium
Dr. Mario Tafalla	ORATED

Observatorio Astronomico Nacional, Spain

Bipolar outflows represent one of the most characteristic signatures of early stellar life and are a favored feedback mechanism to explain the low efficiency of the star-formation process. Despite 30 years of outflow research, many features of their physics still remain mysterious. The underlying driving agent, for example, has been modelled either as a jet or as wide-angle wind, and observations of different outflows seem to favor one or the other picture. In this talk, I will present a current effort to clarify some basic issues ofouflow physics using high-resolution observations of outflows from the youngest protostars, which are expected to reflect more faithfully the properties of the driving wind. The analysis of the kinematics and the chemical composition of the outflow gas suggests that outflows consist of both highly collimated and wide-angle parts, and at least in some cases we may have already observed part of the wind coming from the protostar or its innermost vicinity.

	Main Colloquium
Dr. Tanja Kneiske	ORATED

DESY/UniversitE4t Hamburg

The formation and evolution of galaxies in the local supercluster have very likely lead to the acceleration of energetic particles by individual galaxies as well as in large-scale shocks and turbulences resulting from merging events. Here, the observational signatures in the gamma- and neutrino channel is investigated. They have their origin in cosmic-rays with energies up to a few 1019 eV which are efficiently confined in the intracluster medium, depending on the magnetic field. Subsequent photo-pion production and pair-production/inverse Compton cascades lead to a large-scale anisotropy at TeV and EeV energies along the super-galactic plane. Additionally, energetic neutrinos are produced. Predictions of secondary particle spectra are provided and implications for the cosmic-ray energy density in the local supercluster will be shown.

	Main Colloquium
Tzu-Cheng Peng	ORATED

MPI fuer Radioastronomie

Massive stars play an important role in shaping galactic structure due to a large energy output during their lifetime. However, because of their short evolutionary time scales, large extinction toward their birth places, and large distances of massive stars, our understanding of their formation is still sketchy. In this talk, I will present the observations of two well-known massive star forming regions in our Galaxy (W49A at 11.4 kpc and Orion Molecular Cloud 1 at 414 pc) using the IRAM 30 m and APEX telescopes, and I will focus on the triggered starburst phenomenon in W49A and the molecular gas outflows in the Orion Molecular Cloud 1.

	Main Colloquium
Dr. Laura Spitler	ORATED

MPIfR

The goal of CASPER, the Collaboration for Astronomy Signal Processing and Electronics Research, is to develop a flexible hardware and software platform for the rapid development of digital backends. For my thesis at Cornell, I’m developing several CASPER-based digital spectrometers for surveys using the world’s largest and perhaps smallest radio telescope. In conjunction with the SETI group at the University of California, Berkeley, I’ve built the high resolution spectrometers for the SERENDIP V and soon SERENDIP VI commensal SETI observing programs at the Arecibo Observatory. I will also discuss an all-sky, all-time survey for bright, fast radio transients using the 3.8 meter teaching telescope on the roof of Cornell’s astronomy department.

	Main Colloquium
Dr. Anton Vasyunin	ORATED

MPIA Heidelberg

We study the impact of dust evolution in a protoplanetary disk around a T Tauri star on the disk chemical composition. For the first time we utilize a comprehensive model of dust evolution which includes growth, fragmentation and sedimentation. A chemical model that includes a comprehensive set of gas phase and grain surface chemical reactions is used to simulate the chemical structure of the disk. We find that grain evolution has a major effect on the chemical composition of disks. This comes from the reduction of the total grain surface area above the midplane due to grain growth, and even more importantly, from sedimentation. The net effect of grain growth is suppressed by the fragmentation process which maintains a population of small grains that dominate the total grain surface area. The decrease in grain surface area leads directly to a reduced dust opacity and a different UV field in the disk. The disk becomes more transparent for external UV radiation. This effect is more pronounced in the inner disk, because grain growth is more efficient there. In general, the “three-layer” pattern in the chemical structure is preserved, but is shifted closer to the midplane. Such a disk has a smaller vertical extent compared to a disk without grain evolution. The column densities of most of the gas-phase species are enhanced by 1-3 orders of magnitude relative to those in a model with pristine dust. We show that column densities of certain species, like C2H, H2CO, HC(2n+1)N (n=0-3), H2O and some other molecules, as well as the C2H2/HCN abundance ratio which are accessible with Herschel and ALMA, can be used as observational tracers of early stages of the grain evolution process in protoplanetary disks.

	Main Colloquium
Dr. Hans Kaercher	ORATED

MT Mechatronics, Mainz

Reflecting Radio Telescopes have been built since Grote Reber’s beginnings 1937 in the backyard of his home in Wheaton near Chicago. The construction of large, full steerable single dishes reached a paramount with the construction of the 100m Effelsberg telescope 1968-1971. This telescope had a homologuous passive surface and is limited by the climatic conditions of its site to wavelengths in the cm range. Since then, the technological development goes to shorter wavelengths at higher sites, to larger collecting areas, and to better resolution via telescope arrays. This development will be assessed in the talk - from the engineer’s point of view - by some worldwide examples, e.g. large single dish telescopes with active surfaces or that use exotic materials, namely the 50m LMT in Mexico, the 64m SRT in Sardinia, the 65m ShAO telescope in Shanghai, the 500m FAST telescope in Guizhou, and, as a prime short wavelength example, the proposed 25m CCAT in the high Andes in Chile. The technical issues of the arrays are discussed by the examples of the IRAM array on the Plateau de Bure, the VLBI 2010 array of the geodetic community, which will be distributed worldwide, the ALMA array in the high Andes, and last not least the Square Kilometer Array (SKA), which will be probably built in South-Africa or Australia. The talk will end with a very short outlook on the design of extremely large optical telescopes.

	Special Colloquium
Andreas Horneffer	ORATED

MPIfR Bonn / Radboud University Nijmegen

Radio pulses from cosmic ray induced air showers are known since their discovery in 1965. The LOFAR prototype LOPES was the first experiment to use new technology to detect the radio emissions of air showers. KASCADE-Grande, a well calibrated particle detector array, allowed us to measure the properties of the radio emission. The unprecedented sensitivity and excellent calibration makes LOFAR an unique tool to study the radio properties of single air showers. Precision measurements of the lateral distribution of the pulse height, the shape of the pulse front and the polarization properties of the radio pulse enables us to test and refine our theoretical understanding of the radio emission process. This understanding is necessary to be able to infer the properties of the primary cosmic ray from measurements of the air shower.

	Special Colloquium
Dr. Satej Khedekar	ORATED

Tata Institute of Fundamental Research, Mumbai, India

Ongoing Sunyaev-Zel’dovich (SZ) cluster surveys like the ACT, SPT and Planck have the potential of revealing the nature of dark energy using cluster number count observations. However, the cluster yields in these surveys have been a factor of 4 to 5 lower than what had been anticipated earlier. With such low cluster detections, the cosmological constraints would be washed out due to the infamous cosmology-cluster physics degeneracy. In this context, we discuss two new ideas to significantly improve the constraints on dark energy.

	Main Colloquium
Prof. Eduardo Ros	ORATED

MPIfR

“VLBI is a technique with unprecedented resolution in astronomy” and “VLBI is a way of life” were two sentences I heard during my PhD time, to define what it was and is. After this doctoral period, and to make honour to these sentences, I joined the Max Planck Institute for Radio Astronomy, where I have been spending the last 12,5 years. Now it is time to leave to another location, and it is the occassion to make a short balance of my research in VLBI over these years in this place. In my talk I will touch VLBI topics with keywords like AGN and radio stars, astrometry, polarisation, calibration, jet kinematics, variability, or the connection to higher energy photons.

	Main Colloquium
Dr. Bruce Tsurutani	ORATED

JPL

“Space weather”, to be reviewed in this talk, refers to the continually changing environmental conditions in near-Earth space. It is distinct from the concept of weather within a planetary atmosphere, and deals with phenomena involving ambient plasma, magnetic fields, radiation and other matter in space. Within our solar system, space weather is driven by the speed and density of the solar wind and the interplanetary magnetic field. A variety of physical phenomena are associated with space weather, including geomagnetic storms, energization of the Van Allen radiation belts, ionospheric disturbances, aurora and geomagnetically induced currents at Earth’s surface. Coronal Mass Ejections and their associated shock waves are also important drivers of space weather as they can compress the magnetosphere and trigger geomagnetic storms. The adverse effects of extreme space weather on modern technology – power grid outages, high-frequency communication blackouts, interference with Global Positioning System navigation signals, spacecraft anomalies – are well known and documented. Although the physical processes underlying space weather are generally well understood, our ability to forecast extreme events remains in its infancy.

	Main Colloquium
Prof. Alain Omont	ORATED

Institut d'Astrophysique de Paris

SCUBA and MAMBO surveys at lambda sim1mm have revealed the presence of a rich class of high-redshift powerful starbursts, ultra-luminous in the far-infrared (”submillimeter galaxies”, SMGs). They are probably the progenitors of present day massive elliptical galaxies, caught at the epoch of one of their most important merger events. This field is now revolutionized by the wide-field surveys carried out by space observatories: 1) Spitzer and Herschel have increased the area observed by two and soon three orders of magnitude, respectively; 2) the submm bands of Herschel provide direct information on the far-infrared luminosity and the star formation rate of such galaxies. The first part of my talk will report the results of the detailed study we are completing on the zsim2 ultra-luminous massive starburst galaxies selected by Spitzer in the mid-IR. Spitzer thus allows the selection of more than 100 zsim1.5-2 ULIRGs per deg2, in sim70 deg2, with a far-IR luminosity approaching 10^{13} Lsol/yr (SFRsim1000 Msol/yr), including a major fraction of zsim2 SMGs. We have shown their high detection rate at 1.2mm with MAMBO; checked their far-IR luminosity with 350 mum SHARC2/CSO observations and through the radio/far-IR correlation; studied in detail their prominent mid-IR PAH spectrum and checked its correlation with the far-IR emission; and begun their CO study. I will then present a few preliminary results from the wide-field Herschel surveys, HerMES (sim70 deg2) and H-ATLAS (sim500 deg2), on high redshift ULIRGs. I will focus on the significant far-IR luminosity of most high-z QSOs, and the confirmation of the powerful far-IR luminosity of the zsim2 Spitzer selected starburst ULIRGs.

	Special Colloquium
Kazi Rygl	ORATED

MPIfR Bonn / IMPRS

Star-forming regions trace the spiral structure of the Galaxy. They are regions of increased column density and therefore traced well by the extinction in the mid-infrared. A sample of 25 high extinction clouds (HECs) was studied in the 1.2 mm dust continuum emission, and followed up by observations of ammonia plus several other molecules using the Effelsberg 100m, IRAM 30m and APEX telescopes. With these data we want to investigate the most early stages of massive star formation, which are currently still largely unknown. Three cloud classes were defined from their morphology in the 1.2mm continuum maps: the early diffuse HECs, with a low contrast between the clump and cloud emission; the peaked HECs, with an increased contrast; the late multiply peaked HECs, with more than one clump and a high contrast between the clump and the cloud emission. The clouds are cold (Tsim16K) and massive (Msim800,mathrm{M_odot}) and contain dense clumps (nsim10^5,mathrm{cm^{-3}}) of 0.3pc in size. These clumps were investigated for evidence of gravitational collapse, for high velocity outflows, and for the presence of young stellar objects. Based on these results we interpret the three cloud classes as an evolutionary sequence of star-forming clouds. Accurate distances are a crucial parameter for establishing the mass, size, and luminosity of an object. Also, for understanding the spiral structure of the Galaxy trustworthy distances are necessary. The most accurate method to measure these is the trigonometric parallax. Using the EVN we measured, for the first time, parallaxes of 6.7 GHz methanol masers. This transition belongs to the strongest maser species in the Galaxy, it is stable and observed toward numerous massive star-forming regions. We measured distances and proper motions toward L1287, L1206, NGC281-W, ON1 and S255, and obtained their 3-dimensional space velocities. Similar to previous studies, these star-forming regions rotate slower than Galactic rotation.

	Main Colloquium
Prof. Robert O'Dell	ORATED

Vanderbilt University, Nashville, USA

There has been a lot of attention recently to the Two Decades that the Hubble Space Telescope has been in orbit. As scientists we are familiar with the many results arising from the Hubble. However, the two decades (19 years actually) before that is not widely understood. I will describe the development of the observatory from a unique standpoint, that of the founding Project Scientist. I will go back as far as the first advocacy of a large observatory in space, which occurred in Germany during the Weimar Republic.

	Special Colloquium
Dr. Guenter Knittel	ORATED

Universität Tuebingen

In computer graphics, with the goal of real-time photorealism, and in visualization, with the complex processing of huge data sets, there is no conceivable upper limit of required processing power. The additional constraint of ”consumer-level” size and costs have spurred strong efforts in algorithm optimization, circuit design and system integration. In this talk I will present my previous work in this area. It includes hardware designs for geometry processing, texture mapping, hidden surface elimination, and volume rendering. I will also briefly describe the algorithms which led to the specific architectures. For some of the designs I have used programmable devices such as FPGAs. More recent projects employ GPUs for high-performance computing, such as rendering large textures and volumetric data sets on a display wall. In my last work I have used an own-developed, FPGA-based interconnect within a small GPU-cluster to make GPUs suitable for distributed algorithms with frequent data exchange. As an example I will present an implementation of a parallel, preconditioned conjugate gradient solver for the Poisson problem.

	Main Colloquium
TBA	ORATED

On Friday, June 4 2010 in Bonn will take place the PhDnet conference of the Max Planck Students from around Germany and from all the fields.

	Special Colloquium
Nicolas Pradel	ORATED

ASTRON

Compact symmetric objects are part of the more wide class of AGN known a Giga hertz peaked sources (GPS). Observed with VLBI, they exhibit a very specific source structure, with a symmetry similar to optical AGN of Fanaroff-Riley class II. We have undertaken VLBI phase-referenced observations of a sample of CSO. The long term goal of this observation program is to measure the absolute proper motion of the jets, and further to determine whether these motions are symmetric or not. The accuracy of such a technique was also investigated and it is found to be below 0.1 mas.

	Special Colloquium
Dr. Stan Kurtz	ORATED

UNAM, Mexico

I will present an overview of massive star formation and describe the ionised gas regions that form around massive stars: the so-called compact, ultracompact and hypercompact HII regions. I will briefly trace the historical development in the study of these objects, explaining why the hypercompact regions were only recently discovered. I will present some recent observational and theoretical results on hypercompact HII regions, and conclude by suggesting that hypercompact HII regions may be the end of the line - the final frontier - in the study of massive star formation by means of interstellar plasmas.

	Main Colloquium
Dr. David A. Smith	ORATED

Centre d'Etudes Nucleaires de Bordeaux-Gradignan/IN2P3/CNRS

Before Fermi went into orbit in June, 2008, it was broadly accepted that many young gamma-ray pulsars would be discovered, beyond the seven seen with the Compton Gamma Ray Observatory. It was also clear that some would be in unidentified EGRET sources. Expectations have been surpassed: about 20 young pulsars have indeed been seen. But we have also discovered 24 new ones through gamma-pulsations alone; gamma pulsations from fifteen radio millisecond pulsars; and 18 radio MSPs at the positions of unidentified Fermi sources. Steady emission from some globular clusters is most easily explained by the MSPs therein. Pulsars account for the bulk of the old EGRET mysteries in the Galactic plane. Pulsed gamma-rays turn out to come mainly from the outer magnetosphere, as opposed to the polar cap regions. Fermi has also begun to characterize the GeV emission of the many pulsar wind nebulae associated with these objects. I will summarize what we have seen and learned with Fermi to date, and touch on some of the many ongoing studies.

	Special Colloquium
Abhirup Datta	ORATED

New Mexico Tech/ NRAO

One of the most difficult challenges for the detection of the HI 21cm emission signal during cosmological reionization is the accuracy of the foreground source removal. I will show that bright sources (> 1 Jy) need to be removed from observations of the Murchison Widefield Array (MWA) with a positional accuracy of approximately 0.1 arc-second. This is less than 1% of the synthesized array beam. We also demonstrate that foreground subtraction can only tolerate a residual calibration error of 0.2% in amplitude per UV cell, assuming that individual visibility errors average down over consecutive days. I will also present power spectra of simulated residual foreground subtraction with position and calibration errors. This talk also includes recent results from a search for the HI 21cm absorption towards z approx 5 radio loud objects to search for residual neutral HI from cosmic reionization.

	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.

	Special Colloquium
Dr. Jason Hessels	ORATED

ASTRON

The LOw Frequency ARray (LOFAR) promises to open a new window on the transient radio sky on timescales of nanoseconds to years. An important aspect of this will be the study of radio-emitting neutron stars in their various incarnations: slow pulsars, young pulsars, millisecond pulsars, magnetars, rotating-radio transients, extreme nullers, et cetera. Pulsars and their brethren are the prototype of the more general “fast-transients”, of which it is hoped many exciting new source classes await discovery. I will discuss LOFAR’s impressive ability to observe pulsars and fast transients and will present early observational results prior to the official opening of the telescope. This will include the first pulsar observations made with the LOFAR station located in Effelsberg.

	Main Colloquium
Dr. Anna Watts	ORATED

Anton Pannekoek Astronomical Institute, University of Amsterdam

Neutron stars are stellar corpses that will not die. They have densities so high that nuclei dissolve dissolve to form exotic states of matter. The high densities also allow neutron stars to sustain magnetic fields up to ten orders of magnitude higher than those we can create in terrestrial facilities, in regimes where new electromagnetic processes are expected. These extreme properties power violent explosions, thermonuclear and magnetic, that can be used to reveal the underlying physics. –

	Main Colloquium
Dr. Christopher J. Conselice	ORATED

University of Nottingham

TBA

	Special Colloquium
Dr. Tomasz Kaminski	ORATED

MPIfR

TBA

	Special Colloquium
Markus Schmalzl	ORATED

MPIA, Heidelberg

TBA

	Special Colloquium
Dr. Timea Csengeri	ORATED

MPIfR

I will present IRAM PdBI continuum and molecular line observations towards the 5 most massive dense cores of Cygnus X. Located at 1.7 kpc, Cygnus X offers the opportunity of reaching small scales (less than 2000 AU) to identify individual collapsing objects. A few, but massive fragments are found within these cores, a total of 9 are found to be precursor of OB stars. Comparing the fragmentation properties with theoretical predictions, it seems that the level of fragmentation in these cores is higher than in the turbulence regulated collapse scenario, but is not as high as expected in a pure gravo-turbulent scenario where the distribution of mass is dominated by low-mass protostars. To go one step further in understanding the origin of these massive protostars, we analysed the PdBI H13CO+ and H13CN line emission. In the turbulence regulation scenario, a strong micro-turbulence is expected which should be observed down to the smallest scales. On the other hand a significant effect of competitive accretion could be observed by means of a detailed kinematical study. In these dense gas tracers all the cores indeed exhibit very rich and complex kinematics such as several line components and interacting flows of dense gas are found just around protostars. The level of turbulent support at the scale of protostars is found to be smaller than pointed by previous single-dish observations, which suggest a dynamical origin and fast evolution for the fragmentation of dense cores. To put in context the origin of massive cores, the link between small (0.01 pc) and large (pc) scale kinematics must be investigated. I will briefly present our recent studies of the most massive structure within Cygnus X, the DR21 filament, that point to its dynamic origin.

	Special Colloquium
Dr. Surajit Paul	ORATED

IUCAA, Pune, India

Major cluster mergers are the most energetic events in the structure formation processes. Such events are associated with production of megapersec scale shocks and large scale turbulence. Our discovery of ring-like diffuse radio emission at the virial radius of Abell 3376 indicates a massive and energetic process like cluster merging. Thus to model our observations and in order to study the evolution of merger shocks and the subsequent injection of turbulence in the ICM we performed a set of cosmological simulations of major mergers in galaxy clusters. We used the hydrodynamical code Enzo, with a refinement criterion especially designed for refining turbulent flows in the vicinity of shocks. A comparison study of relaxed and vigorously merging clusters is done in the light of the evolution of density profile, temperature and turbulence. Our results reveal a new time scale of turbulence decay. Turbulence at the cluster center is seen to sustain for several Gigayears ( 4 Gyr), which is substantially longer than typically assumed in the turbulent re-acceleration models, invoked for explaining the statistics of observed radio halos. Lastly we have shown the striking similarities in morphology and other physical parameters obtained from our simulation with the “symmetrical radio relics” found at the periphery of the merging cluster Abell 3376.

	Main Colloquium
Dr. Gianfranco Gentile	ORATED

University of Ghent, Belgium

Dark matter is one of the great mysteries of today’s astrophysics. Its cosmic abundance is thought to be six times larger than the abundance of visible matter. However, the dark matter particle has not been detected (yet?), so that in some astrophysical contexts its very existence is even being questioned. Therefore, it is worth investigating alternatives to galactic dark matter such as MOND (Modified Newtonian Dynamics). After introducing the main issues, I will review the pros and cons of dark matter and MOND to explain observational data, focussing on galaxy scales.

	Special Colloquium
Dipl.-Phys. Simone Bernhart	ORATED

MPIfR Bonn

TBA

	Main Colloquium
Dr. Andrej Sobolev	ORATED

Astronomical Observatory, Ural State University, Ekaterinburg, Russia

The disks around massive stars attract great interest in the astronomic community. These objects have small angular sizes and it is very intriguing to try to explore their physical parameters and kinematics with the extremely high angular resolution achieved in maser research. A review of the diagnostic capabilities of masers for studies of a young massive star environment will be presented. The problems of associating masers with particular components of the circumstellar environment will be described. A report about the discovery of a class II methanol maser in a molecular ring around a young binary system will conclude the talk.

	Special Colloquium
Multiple Speakers: Check abstract for details	ORATED

09:00 Chair: J.A. Zensus T. Savolainen - Blazar demographics with the MOJAVE program T. Krichbaum - Towards the Imaging of Black Holes - High frequency VLBI of Sagittarius A* (and other AGN) L. Fuhrmann - Multi-frequency monitoring of γ-ray blazars in the Fermi-GST era - The F-GAMMA project J. Anderson - LOFAR Progress at the MPIfR 09:45 Chair: M. Kramer M. Kramer - Fundamental physics in radio astronomy W. Reich - Galactic Polarisation Surveys L. Guillemot - Fermi Observations of Gamma-ray Pulsars E. Barr - Radio observations of anomalous Fermi sources at Effelsberg D. Champion - Surveys and pulsar timing array N. Wex - Pulsars and the Nature of Gravity 10:30 Coffee Break 11:00 Chair: G. Weigelt M. Kishimoto - Infrared interferometry of active galactic nuclei K. Ohnaka - Infrared interferometry of stars in late evolutionary stages J. Groh - Infrared interferometry of young stellar objects 11:45 Chair: K.M. Menten K. Rygl - Massive star-forming regions across the Galaxy A. Brunthaler - Micro-arcsecond astrometry in the Milky Way and beyond A. Belloche - Search for new molecules in the ISM

	Main Colloquium
Dr. Thomas Tauris	ORATED

Niels Bohr Institute/Copenhagen University

Ever since their discovery, close binary systems hosting neutron stars, black holes or white dwarfs have constituted an interesting challenge for modern astrophysicists. In this talk I briefly review stellar evolution and interactions in close binaries, including aspects of the stability of mass transfer in X-ray binaries, the common envelope and spiral-in phase and the dynamical effects of asymmetric supernovae. I discuss how a system needs very fine-tuned evolution in order to survive all the way to the end forming a double degenerate binary which will eventually merge and become a source for LIGO.

	Main Colloquium
Dr. Fumi Egusa	ORATED

Caltech, Pasadena, USA

As all the stars are formed in molecular clouds, it is essential to study physical properties and evolution of molecular gas for understanding star formation processes. In Egusa et al. (2009), we examined spatial offsets between CO and H-alpha seen in nearby spiral galaxies. Based on the density wave theory, these offsets should represent (1) star formation timescale, i.e., time to form stars and be bright in H-alpha from molecular clouds detected in CO, and (2) velocity difference between materials (gas and stars) and the spiral pattern. By measuring offsets in a range of radius, we derived the 2 unknown parameters, i.e., the star formation timescale and pattern speed, for 5 galaxies. Since the derived star formation timescale of 5-30 Myr is consistent with the Jeans timescale for typical molecular clouds, we conclude that the dominant trigger for star formation at a few 100 pc (spatial resolution of CO data) is the gravitational instability of molecular gas. To study the internal structure of molecular clouds with size of 100 pc or more, so-called Giant Molecular Associations (GMAs), on the other hand, we have carried out high resolution CO observations toward a spiral arm in the nearby galaxy M 51 with CARMA. The spatial resolution and sensitivity are slightly smaller than typical size (40 pc) and mass (10^5 Msun) of Giant Molecular Clouds (GMCs), respectively. Within the 1 arcmin field of view, we have found that the most massive (>10^6 Msun) clumps are located downstream of the spiral arm spatially as well as kinematically and have nearby star forming regions, which indicates that these clumps are at later stage of molecular gas evolution and plausibly cores of GMAs. In addition, the missing flux in the high resolution data amounts to 90%. We thus conclude that GMAs are not confusion of GMCs but are discrete and smooth structures with a core.

	Special Colloquium
Dr. Stephane Sacuto	ORATED

Universität Wien

We study the circumstellar environment of the carbon-rich star R Sculptoris using the near- and mid-infrared high spatial resolution observations from the ESO-VLTI focal instruments VINCI and MIDI, respectively. These observations aim at increasing our knowledge on the dynamic processes at play within the very close circumstellar environment where the mass-loss of AGB stars is initiated. We first compare the spectro-interferometric measurements of the star at different epochs to detect the dynamic signatures of the circumstellar structures at different spatial and spectral scales. We then interpret these data using a self-consistent dynamic model atmosphere to discuss the dynamic picture deduced from the observations. Interferometric observations show that the structures located in between the photosphere and the dust condensation zone, corresponding to extended (1.5 to 2 stellar radii) warm molecular layers, are sensitive to the stellar pulsation. We also find that these layers are very reactive to the brightness fluctuation of the star, showing a significant change in a small time interval close to the maximum light. We find a rather good agreement between the dynamic model and the spectro-photometric data. The model structure is suitable in the near-infrared. In the mid-infrared, the extended warm molecular layers of C2H2 and HCN are predicted self-consistently, whereas the model structure is not able to reproduce the more extended dusty environment. Among the different explanations for the discrepancy between the model and the measurements, the strong non-equilibrium process of dust formation is one of the most probable.

	Special Colloquium
Dr. Bhaswati Mookerjea	ORATED

Tata Institute of Fundamental Research, Mumbai, India

Observational and theoretical studies of star formation over the last decade or so have increasingly strengthened the idea that massive young stars play an important role in triggering the formation of subsequent generation of stars. Many of the observations can be reasonably well explained by the two most commonly used models: Radiation Driven Implosion (RDI) and Collect-and-Collapse. One general problem of scenarios of triggered star formation is that it is hard to obtain a clear proof of causality, YSOs and ongoing star formation near shocks do not necessarily imply triggered star formation. Additional estimates of age and age-spread of the YSOs are required to convincingly prove the triggering of star formation.

	Main Colloquium
Maik Wolleben	ORATED

MPIfR

The Global Magneto-Ionic Medium Survey (GMIMS) is a project to map the diffuse polarized emission over the entire sky, northern and southern hemispheres, from 300 MHz to 1.8 GHz. Its major goal is to study the 3-dimensional distribution of the Magneto-Ionic Medium in our Galaxy using Rotation Measure Synthesis. Fundamental question about the origin of the Galactic magnetic field and its influence on processes in the interstellar medium will be studied. GMIMS surveys are carried out with the DRAO 26-m Telescope, the Parkes 64-m Telescope, and will be proposed for the Effelsberg 100-m and Kunming 40-m telescopes. I will talk about the technical and observational challenges, and present first results from the on-going surveys.

	Main Colloquium
Dr. Jens Chluba	ORATED

CITA, Toronto

Very soon the Planck Surveyor will start observing the CMB temperature and polarization anisotropies with unprecedented precision. For the analysis of these data sets it will be very important to understand the ionization history of the Universe at redshift z 1100 with very high accuracy, since otherwise uncertainties in the modelling of the recombination process may lead to significant biases in the deduced values of some cosmological parameters. In addition to the simple fact that electrons are captured by protons and helium ions also some photons are released during the cosmological recombination process, leading to small distortions in the CMB blackbody spectrum which should still be present today. This recombination radiation carries valuable information about the dynamics of recombination and the underlying cosmological parameters, which until now has not been accessed. In my talk I will review some of the recent computations in connection with the ionization history of the Universe and the CMB power spectra, showing that neglecting details in the physics of recombination will lead to important biases in the values of n_s and Omega_b. Furthermore, I will try to show that one could learn a lot about cosmological parameter, details in the recombination dynamics, energy release at high redshift and possible dark matter annihilations during recombination by directly measuring the cosmological recombination radiation.

	Special Colloquium
Dr. Tomoya Hirota	ORATED

NAOJ

In this colloquium, I will present our recent results from VERA (VLBI Exploration of Radio Astrometry), which is a Japanese VLBI network dedicated to phase-referencing VLBI astrometry. In particular, I will focus on one of our scientific projects Ästrometry of nearby star-forming regions. Since 2004, we have carried out multi-epoch VLBI monitoring observations of about 10 young stellar objects (YSOs) associated with the H2O masers in nearby molecular clouds. So far, we have successfully measured the annual parallaxes of Orion KL in Orion (Hirota et al. 2007, Kim et al. 2008), IRAS16293-2422 in Ophiuchus (Imai et al. 2007), NGC1333-SVS13 in Perseus (Hirota et al. 2008a), and L1204G in Cepheus (Hirota et al. 2008b). The main goal of our study is to measure the absolute proper motions and distances to nearby molecular clouds within 1 kpc from the Sun to reveal their 3-dimensional structures. This will also enable us to reveal 3-D structure of the local arm of our Galaxy.

	Main Colloquium
Dr. Elisabetta Majerotto	ORATED

Milan Observatory (OAB-INAF)

I will present an interacting dark energy model, where the interaction is proportional to the dark matter density. I will show the conditions to be imposed on the early-time dark energy equation of state parameter in order to give adiabatic initial conditions and viable cosmologies. As supernovae Ia or baryon acoustic oscillation data require the recent-time equation of state parameter to be more negative than the early-time equation of state, we consider a time-varying equation of state in our model. We apply the derived initial conditions and perform a full Monte Carlo Markov Chain likelihood analysis of this model. We use observations of cosmic microwave background anisotropies, supernova luminosities and the baryon acoustic oscillation signal in the galaxy distribution to constrain the cosmological parameters and find that the combination of the three data sets confines the interaction constant to be less than 23% of the expansion rate of the Universe.

	Main Colloquium
Prof. Pavel Kroupa	ORATED

Universität Bonn

The stellar IMF is the distribution function of stellar masses born together in one causally connected event within a spatial region of not more than a few pc in extend. It cannot be measured in any system, but statistical methods combined with corrections for dynamical bias allows one to infer the existence of a universal canonical IMF as the parent distribution from which the various simple stellar populations are drawn. There is no evidence for variation of the IMF except at the highest star-burst cluster masses above 106 Msun and in the immediate vicinity of the Galactic super massive black hole. The IMF in a whole galaxy is, in contrast, that of a composite population such that the IMFs of the individual simple populations must be added. This leads to an integral over the currently forming star cluster population and implies the integrated galactic IMF (IGIMF) to be top light. The steepness of the IGIMF for massive stars can be shown to depend on the star formation rate of the galaxy. This leads to an entirely new avenue of understanding galaxy evolution with potentially deep insights into fundamental physics issues.

	Main Colloquium
Prof. J. Wilms	ORATED

Universität Bamberg

The accretion outflows of stellar mass black holes in Galactic Black Holes and of Active Galactic Nuclei are very similar. Both consist of a central black hole, an accretion disk, and a relativistic matter outflow. Because the characteristic time scales around black holes scale with black hole mass, observations of stellar mass and supermassive black holes allow us to probe very different regimes of what is seen by many as essentially the same phenomenon. In this talk I will discuss the recent progress made in studying the phenomenology and physics of accretion flows onto Galactic Black Holes, both in terms of their spectroscopic behavior and also their short and long-term variability, and how they relate to the physics of AGN.