1:30–2:30 pm ERC 401
Ethan Nadler, Stanford University
“The Galaxy--Halo Connection Including the Impact of the Large Magellanic Cloud”
Host: Alex Drlica-Wagner
The population of Milky Way (MW) satellites contains the faintest known galaxies, and thus provides essential insight into galaxy formation and dark matter microphysics. Here, we present a model of the galaxy–halo connection combined withnewly derived observational selection functions based on satellite searches in DES and Pan-STARRS to fit the position-dependent MW satellite luminosity function. We report decisive evidence for the statistical impact of the LMC system on the MW satellite population due to an estimated 6.5 ± 1.5 currently observed LMC-associated satellites, consistent with the number of LMC satellites inferred from Gaia proper motion measurements. Moreover, we show based on satellite abundances that the LMC fell into the MW within the last 2 Gyr, and we find that the faintest observed satellites inhabit halos with peak virial masses below 2 × 10^8 M⊙ at 95% confidence. We place robust constraints on the fraction of halos that host galaxies in this low-mass regime, and we predict that the faintest potentially detectable satellites occupy halos with peak virial masses above 10^6 M⊙.Event Type
Jan
30