Binarity and dynamics of open clusters

Main Colloquium
Dr. Vikrant Jadhav
SCHEDULED
AIfA

Binary stars play a vital role in astrophysical research, as the majority of stars are in binaries. I will discuss the photometric identification of binaries in open clusters along with their cluster membership. The binary fraction of open clusters ranges from 0.2 to 0.6 and it varies with the mass of the primary stars. I will summarise a few studies focused on the evolution and detection of peculiar binary products such as blue stragglers and blue lurkers using Gaia and UVIT data. I plan to also present our ongoing work regarding the cluster dynamics, specifically signatures of rotation and expansion in open clusters.

Trigerring magnetized outflows near a rotating black hole

Special Colloquium
Prof. Dr. Vladimir Karas
SCHEDULED
Astronomical Institute of the Czech Academy of Sciences

Summarizing essential aspects of GR MHD modelling.

TBD

Special Colloquium
Dr. Emma Perracchione
SCHEDULED
Università di Genova

TBD

TBD

Main Colloquium
Prof. Dr. Günther Hasinger
SCHEDULED
DZA

TBD

An L-Band Panoramic View of the Milky Way Galaxy with the Australian SKA Pathfinder

Special Colloquium
Dr. Roland Kothes
SCHEDULED
DRAO

With the Evolutionary Map of the Universe (EMU) and the Polarization Sky Survey of the Universe's Magnetism (POSSUM), the touchstone radio continuum and polarization surveys of the southern hemisphere are now under way. EMU and POSSUM use the Australian SKA Pathfinder (ASKAP) telescope to image the southern sky to a sensitivity of 20 μJy/beam rms with a resolution of 16ʺ over the next five years. Covering the southern hemisphere, EMU is ideal for observing the Milky Way, cataloguing stars, planetary nebulae, supernova remnants, HII regions, and more, in various stages of evolution, while POSSUM provides sensitive polarization and Faraday rotation images to study magnetic fields in supernova remnants and pulsar wind nebulae and the Galactic magneto-ionic medium. In my presentation I will show the analysis of the Galactic pilot field and early science results with the full EMU and POSSUM surveys.

TBD

Main Colloquium
Dr. Frank Eisenhauer
SCHEDULED
MPE Garching

TBD

Highlights from two surveys of Galactic star clusters (UOCS and GlobULeS) using AstroSat

Special Colloquium
Prof. Annapurni Subramaniam
SCHEDULED
Indian Institute of Astrophysics, Bangalore

The Ultraviolet Imaging Telescope (UVIT) on AstroSat has been producing excellent images in the far-UV since it started operations in 2015. I lead two surveys using UVIT, to study open and globular clusters. We have completed 10 publications in the UVIT Open Cluster study (UOCS) series that cover blue stragglers, white dwarfs, sub-dwarfs and planetary nebulae. The Globular cluster UVIT Legacy Survey (GlobULeS) with 5 publications, has produced a far-UV catalog of several globular clusters, detection of a far-UV dim HB population in the most massive globular cluster Omega Centauri along with the binary blue straggler population of the core-collapsed cluster NGC 362. I plan to summarise the important results that we have obtained from these two surveys and the open questions arising out of these studies.

TBD

Main Colloquium
Dr. Torsten Enßlin
SCHEDULED
MPA Garching

TBD

Studying magnetic fields, dynamics, and fundamental physics near a black hole with current and future mm-VLBI instruments

Special Colloquium
Dr. Freek Roelofs
SCHEDULED
CFA

The Event Horizon Telescope (EHT) has imaged the black hole shadows of the supermassive black hole at the center of the galaxy M87 (M87*) and at the center of the Milky Way (Sgr A*). Polarimetric imaging of M87* with the EHT enabled significantly stronger inferences on the black hole and accretion parameters than total intensity data alone. Geometric modeling was a central tool for studying the structure of M87* and Sgr A* in total intensity. In the first part of the talk, I will show the results of fitting a new polarimetric “m-ring” geometric model to EHT observations of M87*. Our geometric modeling results are generally consistent with imaging methods, but they also enable studies of the black hole when imaging methods struggle, such as nights with sparse coverage or weak signals. In the second part of the talk, I will focus on plans and science goals for future instruments. The Next-Generation EHT (ngEHT) will be a transformative enhancement of the EHT, with array expansions and improvements allowing for, e.g., high dynamic range imaging of AGN jets, and for real-time movie reconstructions of variable sources like Sgr A*. With the ngEHT Analysis Challenges, we explore the science capabilities of the ngEHT, and develop new analysis algorithms capable of analyzing the large and complex ngEHT datasets. Finally, I will give a brief overview of several proposals to image black holes using space-based telescopes, which achieve order-of-magnitude angular resolution improvements compared to what is attainable from the ground and allow for high-precision tests of general relativity.

TBD

Main Colloquium
Prof. Dr. Wolfgang Duschl
SCHEDULED
University of Kiel

TBD