Kavli Affiliate: Andrey Kravtsov
| First 5 Authors: Andrey Kravtsov, Sophia Winney, , ,
| Summary:
We present a study illustrating the effects of the passage of a Large
Magellanic Cloud (LMC) mass satellite on the distance and velocity
distributions of satellites in $Lambda+$Cold Dark Matter simulations of Milky
Way (MW) sized halos. In agreement with previous studies, we find that during
such a passage the velocity distribution develops a high-velocity tail due to
the reflex motion of the inner part of the halo, which can bias velocity-based
virial halo mass estimates. When the velocity distribution of MW satellites is
corrected for effects of the LMC passage, it is consistent with the
distributions in halos of masses as low as $M_{rm 200c}=8times 10^{11},
M_odot$ and as high as $1.5times 10^{12},M_odot$. We present a new halo
mass estimator $M_{rm 200c}=csigma^2_{rm 3D}r_{rm med}$, where $c$ is a
constant calibrated using satellite systems in the simulated MW-sized halos,
$sigma^2_{rm 3D}$ is the variance of 3D velocities taken with the sign of the
radial velocity of each satellite, and $r_{rm med}$ is the median halocentric
distance of the satellites. We show that the estimator has only $s=8%$ scatter
around the median relation of the estimated and true halo masses and deviates
by $<2s$ from the median during the pericentric passage of an LMC-like subhalo.
This is because $sigma^2_{rm 3D}$ and $r_{rm med}$ deviate in opposite
directions during such passages. We apply the estimator to the MW satellite
system and estimate the virial mass of the Milky Way of $M_{rm 200c}=9.96pm
1.45times 10^{11}, M_odot$, in good agreement with several recent estimates
using other methods.
| Search Query: ArXiv Query: search_query=au:”Andrey Kravtsov”&id_list=&start=0&max_results=3