The Dark Energy Camera has captured a large set of images as part of Science Verification (SV) for the Dark Energy Survey. The SV footprint covers a lar ge portion of the outer Large Magellanic Cloud (LMC), providing photometry 1.5 magnitudes fainter
than the main sequence turn-off of the oldest LMC stel lar population. We derive geometrical and structural parameters for various stellar populations in the LMC disk. For the distribution of all LMC stars, we find an inclination of $i=-38.14^{circ}pm0.08^{circ}$ (near side in the North) and a position angle for the line of nodes of $theta_0=129.51^{circ}pm0.17^{circ}$. We find that stars younger than $sim 4$ Gyr are more centrally concentrated than older stars. Fitting a projected exponential disk shows that the scale radius of the old populations is $R_{>4 Gyr}=1.41pm0.01$ kpc, while the younger population has $R_{<4 Gyr}=0.72pm0.01$ kpc. Howe ver, the spatial distribution of the younger population deviates significantly from the projected exponential disk model. The distribution of old stars suggests a large truncation radius of $R_{t}=13.5pm0.8$ kpc. If this truncation is dominated by the tidal field of the Galaxy, we find that the LMC is $simeq 24^{+9}_{-6}$ times less massive than the encircled Galactic mass. By measuring the Red Clump peak magnitude and comparing with the best-fit LM C disk model, we find that the LMC disk is warped and thicker in the outer regions north of the LMC centre. Our findings may either be interpreted as a warped and flared disk in the LMC outskirts, or as evidence of a spheroidal halo component
We report on the discovery of a new Milky Way companion stellar system located at (RA, Dec) = (22h10m43.15s, +14:56:58.8). The discovery was made using the eighth data release of SDSS after applying an automated method to search for overdensities in
the Baryon Oscillation Spectroscopic Survey footprint. Follow-up observations were performed using CFHT-MegaCam, which reveal that this system is comprised of an old stellar population, located at a distance of 31.9+1.0-1.6 kpc, with a half-light radius of r_h = 7.24+1.94-1.29 pc and a concentration parameter of c = 1.55. A systematic isochrone fit to its color-magnitude diagram resulted in log(age) = 10.07+0.05-0.03 and [Fe/H] = -1.58+0.08-0.13 . These quantities are typical of globular clusters in the MW halo. The newly found object is of low stellar mass, whose observed excess relative to the background is caused by 96 +/- 3 stars. The direct integration of its background decontaminated luminosity function leads to an absolute magnitude of MV = -1.21 +/- 0.66. The resulting surface brightness is uV = 25.9 mag/arcsec2 . Its position in the M_V vs. r_h diagram lies close to AM4 and Koposov 1, which are identified as star clusters. The object is most likely a very faint star cluster - one of the faintest and lowest mass systems yet identified.
