Wednesday Colloquium


"Testing General Relativity with gravitational waves"

Michał Bejger (NCAC, Warsaw)


"Hierarchical formed young star clusters: Is resistance to gas-expulsion really futile?"

Michael Fellhauer (Departamento de Astronomia Universidad de Concepcion)

In this talk I will review the work of our group on the dynamics of young embedded star clusters and their survival to gas-expulsion. With our simplified N-body models we have established a new theory to predict the survivability of young star forming regions to gas-expulsion. Using more advanced models we then have shown that those clusters should rather populate the region in parameter space which allows them to survive very well. I will also show what we think are the new gang of culprits for the destruction of young small star clusters, a process dubbed infant mortality.


"The Astrophysics of BH-BH/NS-NS Mergers with LIGO/Virgo"

Krzysztof Belczyński (Copernicus Astronomical Center, Warsaw)

I will discuss the astrophysical importance of the recent LIGO direct detections of gravitational-waves. Despite majority of the expectations, it was not neutron star mergers being detected, but the series of exotic massive black hole mergers. I will discuss the leading theories of the formation of such black hole systems. I will also comment on a potential (rumored) detection of NS-NS merger in the current LIGO/Virgo data. If true it may provide striking constraints on binary evolution predictions. Several astrophysical implications are beginning to emerge despite the fact that the exact origin of LIGO/Virgo sources is not yet known.


"Chemical Evolution of Galaxies from Nuclear Astrophysics to Cosmological Structure Formation"

Benoit Côté ( Konkoly Observatory of the Hungarian Academy of Sciences)

Galactic chemical evolution (GCE) is a multidisciplinary topic that involves nuclear physics, stellar evolution, galaxy evolution, observation, and cosmology. Observations, experiments, and theories need to work together in order to build a comprehensive understanding of how the chemical elements synthesized in astronomical events are spread inside and around galaxies and recycled into new generations of stars. The purpose of GCE is to better understand the origin of the elements in the universe and to use chemical abundances to investigate how galaxies form and evolve in a cosmological context. During this talk, I will introduce the basics of GCE and present our efforts to create permanent connections between different fields of research (including nucleosynthesis and gravitational wave physics). In particular, I will present how we used our tools to investigate the possible production sites of light and heavy elements, to quantify output uncertainties and the impact of different modeling assumptions in galaxy models, and to study how structure formation (galaxy mergers) affects the chemical evolution of galaxies in the early universe.