Our Galaxy’s Center: a Window into the High-Redshift Universe

Main Colloquium
Prof. Cara Battersby
SCHEDULED
University of Connecticut

Galaxy centers are the hubs of activity that drive galaxy evolution, from supermassive black holes to dense stellar clusters and feedback from newly-formed stars. Our own galaxy’s center has properties (densities, temperatures, and turbulent line widths) that are reminiscent of galaxies at the peak of cosmic star formation, but in our own cosmic backyard, where the interplay of these physical processes can be resolved in detail. In this talk, I will discuss gas inflow into our Galaxy’s Center, properties of the gas, and incipient star formation. I will discuss simulations of gas flows into the Galactic Center, which are thought to contribute to the unusual properties of star formation in this region, namely that it is producing 10 times fewer stars than predicted by standard scaling relations. I will describe observations of the gas and incipient star formation in this region, as well as discuss efforts to measure whether or not this unusual environment results in a change to the Initial Mass Function.

The physical and chemical condition of Thackeray 1

Master Colloquium
Shampa Bhusal
SCHEDULED
Max-Planck-Institut für Radioastronomie

Globules, associated with H II regions, are one of the best laboratories to study the impact of stellar radiation and feedback from expanding H II regions on the surrounding medium. First detected by A. D. Thackeray (1950) in the southern H II region IC 2944, the so-called Thackeray’s globules are prime examples of such objects. In this thesis, I present APEX telescope observations of the largest globule in the complex, Thackeray 1, in low level rotational transition of CO and [CI], together with an unbiased spectral line survey in the 230 GHz atmospheric window. I have used this data to probe the physical and chemical conditions of the molecular gas and the photo dissociation regions (PDR) in Thackeray 1. The velocity resolved CO observations suggest that the largest globule is the overlap of two separate regions with masses ~ 11 Msun and 3 Msun corresponding to Thackeray 1A and Thackeray 1B, whereas the continuum dust emission with LABOCA 870 mum reveals an overall mass of ~ 19 Msun . The two regions are kinematically separated with velocities of -20 and -25 km s-1. The line survey reveals for the first time an unbiased view on the chemical molecular composition of these globules, with new detection of molecules such as C18O (2–1), H2CO(3 0,3 – 2 0,2 ), SO, HCN, HNC, HCO+, C2H and CS. MCweeds is used to constrain the column densities and abundances of these species. The incident FUV field intensity, G0 and hydrogen nucleus volume density n are estimated by using PDRTool box models constrained by observed CO line ratios. The data allows to investigate the stability of the globule by estimating their virial mass and ionization timescale. Both parameters confirm previous studies, including the HST image result, that the globule complex, Thackeray 1 is on the verge of breaking up or evaporating. [Referees: Prof. Dr. Karl Menten, Prof. Dr. Frank Bigiel]

Interstellar scintillation and polarization of PSR J0538+2817 and PSR B0659+1414

Main Colloquium
Dr. Jumei Yao
SCHEDULED
National Astronomical Observatories, Chinese Academy of Sciences, Beijing, China

SNR shells have long been suspected as the culprits for dominating pulsar scattering. The interstellar scintillation observation of pulsars associated with SNRs provide us with great opportunity to find evidence for this and reveal the properties of the compact ionized structures. Using FAST, we did high sensitivity interstellar scintillation and polarization observations of PSR J0538+2817 and PSR J0659+1414. For PSR J0538+2817, we found that the shell of SNR S147 dominates its scattering and detected the first evidence for pulsar three-dimensional spin-velocity alignment. The scattering of PSR J0659+1414 is dominated by two different compact regions, the shell of the Monogem ring and the Local Bubble. And the polarization analysis shows that the spin and velocity vectors of PSR J0659+1414 are significantly misaligned.

TBD

Main Colloquium
Dr. Ian Heywood
SCHEDULED
University of Oxford, UK

TBD

TBD

Main Colloquium
Dr. Violette Impellizzeri
SCHEDULED
Leiden Observatory, The Netherlands

TBD

New insights into Galactic magnetism from the THOR survey

Special Colloquium
Prof. Jeroen Stil
SCHEDULED
University of Calgary, Canada

TBD

Cold chemistry in hot cores: new modeling treatments of complex molecule formation in star-forming regions

Main Colloquium
Prof. Robin Garrod
SCHEDULED
University of Virginia

TBD

A legacy investigation of interstellar magnetic polarization in star forming filaments

Main Colloquium
Dr. Thushara Pillai
SCHEDULED
MIT Haystack Observatory, USA

TBD

TBD

Main Colloquium
Dr. Marco Berton
SCHEDULED
European Southern Observatory, Santiago, Chile

TBD

The Galactic centre: structure and dynamics of a unique astrophysical target

Main Colloquium
Dr. Mattia Sormani
SCHEDULED
Universität Heidelberg

TBD

TBD

Main Colloquium
Prof. Jessica Dempsey
SCHEDULED
Netherlands Institute for Radio Astronomy (ASTRON)

TBD

Sagittarius A* in its natural habitat

Main Colloquium
Dr. Elena Murchikova
SCHEDULED
Institute for Advanced Study, Princeton, USA

TBD