Main Colloquium
Prof. Henk Hoekstra	SCHEDULED

Leiden Observatory, the Netherlands

In past century we have learned much about the origin and evolution of the Universe. We now know the Universe is 13.8 billion years old, but its main ingredients remain a mystery: atoms make up only 5%. The rest consists of dark matter and dark energy, components for which we lack a fundamental physical theory. Better observations are needed to guide theory and ESA’s Euclid satellite is designed to do just that. Euclid is scheduled for launch in 2022 and will map the distribution of dark matter in the Universe as a function of cosmic time. However many challenges remain if we want to extract accurate cosmological information from these complex data.

	Special Colloquium
Dr. Bernhard Schulz	SCHEDULED

Deutsches SOFIA Institut and NASA Ames Research Center

TBD

	Main Colloquium
Dr. Aina Palau	SCHEDULED

Instituto de Radioastronomía y Astrofísica, UNAM, Morelia, Mexico

How stellar clusters form and what determines their number of objects and stellar densities are long-standing questions, intimately related to the fragmentation properties of molecular clouds. It is thought that a number of properties of molecular clouds could influence and determine how clouds fragment. Some of these properties are the density and temperature structure, related to thermal support and gravity, turbulence, stellar feedback, initial angular momentum, and magnetic fields. In this talk I will present an observational campaign aimed at disentangling which of these properties finally control the fragmentation process in the dense parts of molecular clouds, from 0.2 to 0.005 pc scales. Special emphasis will be put on our latest result, a study of the relation between fragmentation and the magnetic field, where we observationally tested, for the first time in a statistically significant sample, the theoretical prediction that a strong magnetic field should suppress fragmentation.

	Main Colloquium
Dr. Mélanie Chevance	SCHEDULED

Astronomisches Rechen-Institut, Zentrum für Astronomie der Universität Heidelberg

The cycling of matter in galaxies between molecular clouds, stars and feedback is a major driver of galaxy evolution. However, it remains a major challenge to derive a theory of how galaxies turn their gas into stars and how stellar feedback affects the subsequent star formation on the cloud scale, as a function of the galactic environment. Star formation in galaxies is expected to be highly dependent on the galactic structure and dynamics, because it results from a competition between mechanisms such as gravitational collapse, shear, spiral arm passages, cloud-cloud collisions, and feedback processes such as supernovae, stellar winds, photoionization and radiation pressure. A statistically representative sample of galaxies is therefore needed to probe the wide range of conditions under which stars form. I will present the first systematic characterisation of the evolutionary timeline of the giant molecular cloud (GMC) lifecycle, star-formation and feedback in the PHANGS sample of star-forming disc galaxies. I will show that GMC are short-lived (10-30 Myr) and are dispersed after about one dynamical timescale by stellar feedback, between 1 and 5 Myr after massive stars emerge. Although the coupling efficiency of early feedback mechanisms such as photoionisation and stellar winds is limited to a few tens of percent, it is sufficient to disperse the parent molecular cloud prior to supernova explosions. This limits the integrated star formation efficiencies of GMCs to 2 to 10 per cent. These findings reveal that star formation in galaxies is fast and inefficient, and is governed by cloud-scale, environmentally-dependent, dynamical processes. These measurements constitute a fundamental test for numerical sub-grid recipes of star-formation and feedback in simulations of galaxy formation and evolution.

	Special Colloquium
Prof. Abigail Vieregg	CANCELED

University of Chicago

TBD

	Special Colloquium
Prof. Abigail Vieregg	SCHEDULED

University of Chicago

The detection of high energy astrophysical neutrinos is an important step toward understanding the most energetic cosmic accelerators. IceCube, a large optical detector at the South Pole, has observed the first astrophysical neutrinos and identified at least one potential source. However, the best sensitivity at the highest energies comes from detectors that look for coherent radio Cherenkov emission from neutrino interactions. I will give an overview of the state of current experimental efforts, including recent results, and then discuss a suite of new experiments designed to discover neutrinos at the highest energies and push the energy threshold for radio detection down to overlap with the energy range probed by IceCube, thus covering the full astrophysical energy range out to the highest energies, and opening up new phase space for discovery. These include ground-based experiments such as RNO-G and IceCube-Gen2, as well as the balloon-borne experiment PUEO.

	Main Colloquium
Prof. Alexander Tchekhovskoy	SCHEDULED

Northwestern University, Evanston, Illinois, USA

TBD

	Main Colloquium
Prof. Annalisa Bonafede	SCHEDULED

Dipartimento di Fisica e Astronomia, Università di Bologna, Italy

TBD

	Main Colloquium
Prof. Talvikki Hovatta	SCHEDULED

Finnish Centre for Astronomy with ESO, University of Turku, Finland

TBD

	Special Colloquium
Dr. Michael Janssen	SCHEDULED

Max-Planck-Institut für Radioastronomie

TBD

	Main Colloquium
Dr. Adam Ingram	SCHEDULED

University of Oxford, UK

TBD

	Main Colloquium
Dr. Nabila Aghanim	SCHEDULED

Institut d'astrophysique spatiale, Université Paris-Saclay, France

TBD

	Main Colloquium
Dr. Mark Walker	SCHEDULED

Manly Astrophysics, Australia

TBD

	Main Colloquium
Dr. Geronimo Villanueva	SCHEDULED

NASA Goddard Space Flight Center, Greenbelt, USA

TBD

	SFB Colloquium
Dr. Holger Kreckel	SCHEDULED

Max-Planck-Institut für Kernphysik, Heidelberg

The Cryogenic Storage Ring (CSR) at the Max Planck Institute for Nuclear Physics in Heidelberg is the largest electrostatic storage ring project in the world. The CSR combines electrostatic ion optics with extreme vacuum and cryogenic temperatures. The storage ring has a circumference of 35 m, and all deflectors are housed in experimental vacuum chambers that can be cooled down to 5 K. It has been shown that within a few minutes of storage inside the CSR infrared-active molecular ions (e.g., CH+, HeH+ and OH-) cool to their lowest rotational quantum states by spontaneous emission of radiation. Equipped with an ion-neutral collision setup and a low-energy electron cooler, the CSR offers unique possibilities for astrochemical experiments under true interstellar conditions. I will present an overview of the capabilities of the CSR, along with first experimental results on collision experiments between cold molecular ions and neutral atoms, free electrons, and photons, yielding quantum state-selective rate coefficients for astrophysically important processes.

	Main Colloquium
Dr. Harish Vedantham	SCHEDULED

Netherlands Institute for Radio Astronomy, Dwingeloo

TBD

	Main Colloquium
Dr. Izaskun Jiménez-Serra	SCHEDULED

Centro de Astrobiología, Madrid, Spain

TBD

	Main Colloquium
Dr. Evan Keane	SCHEDULED

National University of Ireland, Galway

TBD

	Main Colloquium
Dr. John Tobin	SCHEDULED

National Radio Astronomy Observatory, Charlottesville, USA

TBD