Seminarium Ogólne
najbliższe | 2026 | 2025 | 2024 | 2023 | 2022 | 2021 | 2020 | 2019 | 2018 | 2017
Seminarium odbywa się w Piwnicach w sali wykładowej budynku Radioastronomii. Początek o godzinie 11.15.
Udział w seminarium w trybie zdalnym za pośrednictwem BigBlueButton (BBB).
15 czerwca 2026
“The Assembly of Star-Forming Galaxies: Evolution of the Main Sequence and Dust Obscuration out to z ∼ 6″
mgr Jude Wijesekera
Instytut Astronomii, Uniwersytet Mikołaja Kopernika
Streszczenie:
Over the history of the Universe, galaxies have undergone profound transformations, with periods of intense star formation often hidden behind vast clouds of cosmic dust. Understanding the complete picture of this star formation rate density across cosmic time remains one of the fundamental challenges in observational astronomy. By combining deep field observations with far-infrared and submillimeter data, we can trace the properties of hundreds of thousands of galaxies out to redshift z ∼ 6. However, this hidden history reveals unexpected complexities: the star-forming main sequence evolves, dust temperatures rise dramatically in the early universe, and the laws governing dust attenuation shift as galaxies grow in stellar mass. What drives these evolutionary trends? How do the changing luminosity functions and the relationship between infrared excess and ultraviolet light ($IRX$- -β) reflect the growth, gas accretion, and eventual quenching of massive systems? This talk will explore these questions by presenting new determinations of the star-forming main sequence and the evolving far-infrared luminosity function. We will discuss approaches to calibrating mass-dependent dust attenuation and present new insights into the dust-obscured history of cosmic star formation.
29 czerwca 2026
“On the similarity of cosmic structures”
prof. Matthias Bartelmann
Institut für Theoretische Physik, Uniwersytet w Heidelbergu
Streszczenie:
The Universe is filled with structures of vastly different scales: galaxies themselves span many orders of magnitude in mass and size; they agglomerate in galaxy groups and clusters; and they align along filaments tens of millions of lightyears long. Notwithstanding their vastly different sizes, these gravitationally bound structures are internally very similar: for example, the radial profiles of their dominant, dark-matter density differ by scale, but not by shape. Why is this so, and what can we learn from this kind of universality? Does it depend on the nature of dark matter, details of the cosmological model, or of gravity theory? The talk will discuss approaches to these questions, present partial answers, and lead to conjectures about cosmic structures that remain to be tested.