Séminaire/Seminar Galaxies |
| « Dark matter versus dark stars » |
|
Léon Koopmans |
| Massive early-type galaxies are known to contain a large amount of dark matter in their inner regions. How much exactly, however, is still poorly constrained, even though it is an important driver of galaxy formation and could even tell us about the nature of dark matter. One of the main difficulties is that dark matter, and low-mass “dark stars" (<0.3 solar mass) are very hard to tell apart since these stars contribute very little to the light of a galaxy, but they can dominate its stellar mass and mimic dark matter. I will discuss how strong lensing, combined with stellar dynamics and stellar populations studies, can jointly constrain the stellar initial mass function (IMF) of stars in cosmologically-distant galaxies. Jointly, they not only provide a constraint on the IMF slope, but also (for the very first time) on its turnover-mass close to the hydrogen burning limit of stars. |
|
jeudi 30 janvier 2020 - 11:30 Salle 281 Institut d'Astrophysique de Paris |
| Page web du séminaire / Seminar's webpage |