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Title: Digging deeper into the Southern skies: A compact Milky Way companion discovered in first-year Dark Energy Survey data

Here, the Dark Energy Survey (DES) is a 5000 sq. degree survey in the southern hemisphere, which is rapidly reducing the existing north-south asymmetry in the census of MW satellites and other stellar substructure. We use the first-year DES data down to previously unprobed photometric depths to search for stellar systems in the Galactic halo, therefore complementing the previous analysis of the same data carried out by our group earlier this year. Our search is based on a matched filter algorithm that produces stellar density maps consistent with stellar population models of various ages, metallicities, and distances over the survey area. The most conspicuous density peaks in these maps have been identified automatically and ranked according to their significance and recurrence for different input models. We report the discovery of one additional stellar system besides those previously found by several authors using the same first-year DES data. The object is compact, and consistent with being dominated by an old and metal-poor population. DES J0034-4902 is found at high significance and appears in the DES images as a compact concentration of faint blue point sources at ~ 87 {kpc}.
  1. Instituto de Fisica, Porto Alegre (Brazil); Lab. Interinstitucional de e-Astronomia - LIneA, Rio de Janeiro (Brazil). et al.
Publication Date:
Report Number(s):
arXiv:1508.02381; FERMILAB-PUB-15-455-AE; SLAC-PUB-16552
Journal ID: ISSN 0035-8711; 1388125
Grant/Contract Number:
AC02-07CH11359; AC02-76SF00515
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 458; Journal Issue: 1; Journal ID: ISSN 0035-8711
Royal Astronomical Society
Research Org:
SLAC National Accelerator Lab., Menlo Park, CA (United States); Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Contributing Orgs:
DES Collaboration
Country of Publication:
United States
79 ASTRONOMY AND ASTROPHYSICS; globular clusters: general; globular clusters: individual (DES 1); galaxies: dwarf; globular clusters; individual (DES 1)
OSTI Identifier:
Alternate Identifier(s):
OSTI ID: 1256636