The Effects of Dark Matter and Baryonic Physics on the Milky Way Subhalo Population in the Presence of the Large Magellanic Cloud

Kavli Affiliate: Risa H. Wechsler

| First 5 Authors: Ethan O. Nadler, Arka Banerjee, Susmita Adhikari, Yao-Yuan Mao, Risa H. Wechsler

| Summary:

Given recent developments in our understanding of the Large Magellanic
Cloud’s (LMC) impact on the Milky Way’s (MW) dark matter subhalo population, we
compare the signatures of dark matter and baryonic physics on subhalos in MW
systems with realistic LMC analogs. In particular, we study the effects of
self-interacting dark matter (SIDM), warm dark matter (WDM), and the Galactic
disk on the peak maximum circular velocity ($V_{mathrm{peak}}$) function,
radial distribution, and spatial distribution of MW and LMC-associated subhalos
using cosmological dark matter-only zoom-in simulations of MW+LMC systems. For
a fixed abundance of subhalos expected to host dwarf galaxies
($V_{mathrm{peak}}gtrsim 20 mathrm{km s}^{-1}$), SIDM and WDM can produce
a similar mass-dependent suppression of the subhalo $V_{mathrm{peak}}$
function, while disk disruption is mass independent. Subhalos in the inner
regions of the MW are preferentially disrupted by both self-interactions and
the disk, while suppression in WDM is radially independent. The relative
abundance of LMC-associated subhalos is not strongly affected by disk
disruption or WDM, but is significantly suppressed in SIDM due to
self-interactions with the LMC at early times and with the MW during LMC infall
at late times, erasing spatial anisotropy in the MW subhalo population. These
results provide avenues to distinguish dark matter and baryonic physics by
combining properties of the MW and LMC subhalo populations probed by upcoming
observations of satellite galaxies and stellar streams.

| Search Query: ArXiv Query: search_query=au:”Risa H. Wechsler”&id_list=&start=0&max_results=10

Read More

Leave a Reply