101 research outputs found
ELVES III: Environmental Quenching by Milky Way-Mass Hosts
Isolated dwarf galaxies usually exhibit robust star formation but satellite
dwarf galaxies are often devoid of young stars, even in Milky Way-mass groups.
Dwarf galaxies thus offer an important laboratory of the environmental
processes that cease star formation. We explore the balance of quiescent and
star-forming galaxies (quenched fractions) for a sample of ~400 satellite
galaxies around 30 Local Volume hosts from the Exploration of Local VolumE
Satellites (ELVES) Survey. We present quenched fractions as a function of
satellite stellar mass, projected radius, and host halo mass, to conclude that
overall, the quenched fractions are similar to the Milky Way, dropping below
50% at satellite M* ~ 10^8 M_sun. We may see hints that quenching is less
efficient at larger radius. Through comparison with the semi-analytic modeling
code satgen, we are also able to infer average quenching times as a function of
satellite mass in host halo-mass bins. There is a gradual increase in quenching
time with satellite stellar mass rather than the abrupt change from rapid to
slow quenching that has been inferred for the Milky Way. We also generally
infer longer average quenching times than recent hydrodynamical simulations.
Our results are consistent with models that suggest a wide range of quenching
times are possible via ram-pressure stripping, depending on the clumpiness of
the circumgalactic medium, the orbits of the satellites, and the degree of
earlier preprocessing.Comment: 18 pages, 12 figures, replaced post-refereeing, no major change
ELVES IV: The Satellite Stellar-to-Halo Mass Relation Beyond the Milky-Way
Quantifying the connection between galaxies and their host dark matter halos
has been key for testing cosmological models on various scales. Below , such studies have primarily relied on the satellite galaxy
population orbiting the Milky Way. Here we present new constraints on the
connection between satellite galaxies and their host dark matter subhalos using
the largest sample of satellite galaxies in the Local Volume () to date. We use confirmed and candidate dwarf
satellites around 27 Milky Way (MW)-like hosts from the Exploration of Local
VolumE Satellites (ELVES) Survey and use the semi-analytical SatGen model for
predicting the population of dark matter subhalos expected in the same volume.
Through a Bayesian model comparison of the observed and the forward-modeled
satellite stellar mass functions (SSMF), we infer the satellite stellar-to-halo
mass relation. We find that the observed SSMF is best reproduced when subhalos
at the low mass end are populated by a relation of the form , with a moderate slope of and a low scatter, constant as a function of the peak halo mass, of
. A model with a steeper slope
() and a scatter that grows with decreasing
is also consistent with the observed SSMF but is not
required. Our new model for the satellite-subhalo connection, based on hundreds
of Local Volume satellite galaxies, is in line with what was previously derived
using only the Milky Way satellites.Comment: Accepted for publication in ApJ. Figure 8 shows the key result -- the
Satellite Stellar to Halo Mass relation obtained in this work, in comparison
to previous studie
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