The latest puzzle in narrow-line Seyfert 1 galaxies: invisible jets?

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

Narrow-line Seyfert 1 (NLS1) galaxies are a subclass of active galactic nuclei (AGN) identified more than 30 years ago, but still not entirely understood. These objects are likely characterized by rapidly growing low-mass black holes. Interestingly enough, some of them have been detected in gamma-rays, a sign that they can harbor powerful relativistic jets. In my talk I will review their properties, showing how the true nature of NLS1s is that of early-stage AGN in a recently triggered activity phase, and how they are connected to other classes of kinematically young jetted AGN. I will also report on the discovery, in a handful of NLS1s, of relativistic jets remarkably faint at low radio frequency, but extremely bright and variable at high radio frequency. New observations of these sources are revealing an increasingly complicated picture, and I will outline the different scenarios we are developing to explain this new, unexpected phenomenon.

The Renaissance of Astrophysics: a landscape of opportunities in the era of Time Domain Multi-Messenger investigations

Special Colloquium
Prof. Raffaella Margutti
SCHEDULED
Northwestern University, Evanston, Illinois, USA

Astronomical transients are signposts of catastrophic events in space, including the most extreme stellar deaths, stellar tidal disruptions by supermassive black holes, and mergers of compact objects. Thanks to new and improved observational facilities we can now sample the night sky with unprecedented temporal cadence and sensitivity across the electromagnetic spectrum and beyond. This effort has led to the discovery of new types of astronomical transients, revolutionized our understanding of phenomena that we thought we already knew, and enabled the first insights into the physics of neutron star mergers with gravitational waves and light. In this talk I will review some very recent developments that resulted from our capability to acquire a truly panchromatic view of transient astrophysical phenomena. I will focus on two key areas of ignorance in the field: (i) What are the progenitors of stellar explosions and what happens in the last centuries before death? (ii) What is the nature of the compact objects produced by these explosions and what happens when compact objects merge? The unique combination of Discovery Power (guaranteed by planned transient surveys across the electromagnetic spectrum, combined with efforts in the realm of artificial intelligence) and Understanding (enabled by multi-messenger observations) is what positions time-domain astrophysics for major advances in the near future.

A shocking shift in paradigm for classical novae

Main Colloquium
Prof. Laura Chomiuk
SCHEDULED
Michigan State University, USA

Over the last decade, our understanding of classical novae has been turned on its head with the discovery of gamma-rays from Galactic eruptions. This discovery has highlighted the value of novae -- non-terminal, thermonuclear eruptions on the surfaces of white dwarfs in binary systems -- as laboratories for studying shocks and particle acceleration. I will discuss where and how shocks form in the nova ejecta, why we think the shocks may actually dominate the energy budget of the nova eruption, and some of the consequences of the shocks, including dust formation and acceleration of particles to very high (TeV) energies. These recent developments place novae amongst the ranks of interaction-powered transients, making them nearby, common examples of the physics that governs more exotic events like Type IIn supernovae, stellar mergers, and tidal disruption events.

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

Main Colloquium
Dr. Mattia Sormani
SCHEDULED
Universität Heidelberg

I will give an introduction to the structure, dynamics and star formation in the centre of the Milky Way. After reviewing the basic theoretical tools, I will discuss several topics including (i) how can we interpret large-scale spectral line datacubes of CO, HI and other interstellar gas tracers in the context of gas flowing in the strongly non-axisymmetric gravitational potential of the Galactic bar; (ii) how can we use the gas dynamics to constrain the properties of the Galactic bar; (iii) what physical processes transport the gas inwards from the Galactic disc (R~3 kpc) to the Central Molecular Zone (CMZ, R~120 pc) and then to the central black hole SgrA*; (iv) what is the spatial and temporal distribution of star formation in the Galactic centre; (v) what are the structure, dynamics and secular evolution of the Nuclear Stellar Disc, the flattened stellar structure that dominates the gravitational potential at Galactocentric radii R between 30 pc and 300 pc. Finally, I will highlight some open questions and directions of future research.

TBD

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

TBD

The key role of astrochemistry in driving planet formation and habitability

SFB Colloquium
Prof. L. Ilsedore Cleeves
SCHEDULED
University of Virginia, Charlottesville, USA

Historically, our perspective on how planets form and obtain their compositions has been motivated by our Solar System. However, we are just one system, and missions like Kepler and TESS have revealed a variety of planetary types and architectures. How do we fit in? In the last five years, the Atacama Large Millimeter Array has revolutionized our understanding of planet formation by observing the process at high spatial resolution (reaching in some cases ~au scales) matched with unprecedented sensitivity at radio wavelengths. In this presentation, I will review recent highlights from the TW Hya as a Chemical Rosetta Stone ALMA project and discuss how these findings both confirm and, in some ways, challenge our current picture of the chemistry of planet formation.

Star-formation and jet activity in radio AGN, near and far

Special Colloquium
Dr. Sthabile Kolwa
SCHEDULED
University of Johannesburg, South Africa

TBD

Sagittarius A* in its natural habitat

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

TBD

TBD

Main Colloquium
Dr. Manisha Caleb
SCHEDULED
University of Sydney

TBD

TBD

Main Colloquium
Dr. Colin Clark
SCHEDULED
Max Planck Institute for Gravitational Physics/Leibniz Universität Hannover

TBD

The multi-messenger hunt for the biggest binary black holes

Main Colloquium
Prof. Sarah Burke-Spolaor
SCHEDULED
West Virginia University Center for Gravitational Waves and Cosmology, USA

TBD

TBD

Main Colloquium
Prof. Ralf Klessen
SCHEDULED
Universität Heidelberg

TBD

Exploring the nanohertz-frequency gravitational-wave landscape with pulsar timing arrays

Main Colloquium
Prof. Stephen Taylor
SCHEDULED
Vanderbilt University, Nashville, USA

TBD

TBD

Main Colloquium
Dr. Maria Rioja
SCHEDULED
ICRAR-UWA/CSIRO, OAN, Australia

TBD

Multi-messenger observations of relativistic transients

Main Colloquium
Prof. Alessandra Corsi
SCHEDULED
Texas Tech University, Lubbock, USA

TBD

Extragalactic Megamaser

Special Colloquium
Dr. Willem Baan
SCHEDULED
ASTRON, The Netherlands

TBD