Search for Gamma-ray Emission from Dark Matter Annihilation in the Large Magellanic Cloud with the Fermi Large Area Telescope

At a distance of 50 kpc and with a dark matter mass of $\sim10^{10}$ M$_{\odot}$, the Large Magellanic Cloud (LMC) is a natural target for indirect dark matter searches. We use five years of data from the Fermi Large Area Telescope (LAT) and updated models of the gamma-ray emission from standard astrophysical components to search for a dark matter annihilation signal from the LMC. We perform a rotation curve analysis to determine the dark matter distribution, setting a robust minimum on the amount of dark matter in the LMC, which we use to set conservative bounds on the annihilation cross section. The LMC emission is generally very well described by the standard astrophysical sources, with at most a $1-2\sigma$ excess identified near the kinematic center of the LMC once systematic uncertainties are taken into account. We place competitive bounds on the dark matter annihilation cross section as a function of dark matter particle mass and annihilation channel.Comment: 33 pages, 22 figures Version 2: minor corrections and clarifications after journal peer review proces

The Dual Origin of Stellar Halos. II. Chemical Abundances as Tracers of Formation History

This paper is a computational study of the formation of the stellar halos of Milky Way-massed galaxies, and the fingerprint of the formation history imprinted on the chemical abundances of those stars. --author-supplied descriptio