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Title: The LMC geometry and outer stellar populations from early DES data

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 large portion of the outer Large Magellanic Cloud (LMC), providing photometry 1.5 magnitudes fainter than the main sequence turn-off of the oldest LMC stellar population. We derive geometrical and structural parameters for various stellar populations in the LMC disc. For the distribution of all LMC stars, we find an inclination of i = –38.14°±0.08° (near side in the North) and a position angle for the line of nodes of θ₀ = 129.51°±0.17°. We find that stars younger than ~4 Gyr are more centrally concentrated than older stars. Fitting a projected exponential disc shows that the scale radius of the old populations is R>4Gyr = 1.41 ± 0.01 kpc, while the younger population has R<4Gyr = 0.72 ± 0.01 kpc. However, the spatial distribution of the younger population deviates significantly from the projected exponential disc model. The distribution of old stars suggests a large truncation radius of Rt = 13.5 ± 0.8 kpc. If this truncation is dominated by the tidal field of the Galaxy, we find that the LMC is ≃24+9–6 times lessmore » massive than the encircled Galactic mass. By measuring the Red Clump peak magnitude and comparing with the best-fit LMC disc model, we find that the LMC disc is warped and thicker in the outer regions north of the LMC centre. As a result, our findings may either be interpreted as a warped and flared disc in the LMC outskirts, or as evidence of a spheroidal halo component.« less
Authors:
 [1] ;  [2] ;  [3] ;  [4] ;  [3] ;  [5] ;  [5] ;  [6] ;  [7] ;  [8] ;  [8] ;  [9] ;  [7] ;  [10] ;  [8] ;  [11] ;  [12] ;  [13] ;  [9] ;  [8] more »;  [5] ;  [14] ;  [15] ;  [16] ;  [8] ;  [9] ;  [8] ;  [17] ;  [18] ;  [8] ;  [8] ;  [19] ;  [20] ;  [21] ;  [7] ;  [22] ;  [8] ;  [9] ;  [23] ;  [15] ;  [24] ;  [25] ;  [5] ;  [8] ;  [8] ;  [11] ;  [26] ;  [7] ;  [8] ;  [21] ;  [6] ;  [24] ;  [8] ;  [27] ;  [28] « less
  1. Univ. of Surrey, Guildford (United Kingdom); Univ. Federal do Rio Grande do Sul, Porto Alegre (Brazil); Lab. Interinstitucional de e-Astronomia, Rio de Janeiro (Brazil)
  2. Brookhaven National Lab. (BNL), Upton, NY (United States)
  3. Univ. Federal do Rio Grande do Sul, Porto Alegre (Brazil); Lab. Interinstitucional de e-Astronomia, Rio de Janeiro (Brazil)
  4. Osservatorio Astronomico di Padova INAF, Padova (Italy)
  5. Lab. Interinstitucional de e-Astronomia, Rio de Janeiro (Brazil); Observatorio Nacional, Rio de Janeiro (Brazil)
  6. Univ. of Illinois, Urbana, IL (United States)
  7. National Optical Astronomy Observatory, La Serena (Chile)
  8. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States)
  9. Univ. College London, London (United Kingdom)
  10. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Space Telescope Science Institute, Baltimore, MD (United States)
  11. Argonne National Lab., Lemont, IL (United States)
  12. Carnegie Observatories, Pasadena, CA (United States)
  13. Univ. Pierre et Marie Curie, Paris (France)
  14. Stanford Univ., Stanford, CA (United States)
  15. Texas A & M Univ., College Station, TX (United States)
  16. Ludwig Maximilian Univ., Munich (Germany); Excellence Cluster Universe, Garching (Germany)
  17. Univ. of Michigan, Ann Arbor, MI (United States); Univ. Pierre et Marie Curie, Paris (France)
  18. Lab. Interinstitucional de e-Astronomia, Rio de Janeiro (Brazil)
  19. Fermi National Accelerator Lab. (FNAL), Batavia, IL (United States); Excellence Cluster Universe, Garching (Germany)
  20. Ludwig Maximilian Univ., Munich (Germany); Max Planck Institute for Extraterrestrial Physics, Garching (Germany)
  21. The Ohio State Univ., Columbus, OH (United States)
  22. Australian Astronomical Observatory, North Ryde (Australia)
  23. Univ. of Pennsylvania, Philadelphia, PA (United States)
  24. Univ. of Michigan, Ann Arbor, MI (United States)
  25. Univ. Autonoma de Barcelona, Bellaterra (Spain); Institucio Catalana de Recerca i Estudis Avancats, Barcelona (Spain)
  26. Centro de Investigaciones Energeticas, Madrid (Spain)
  27. Univ. of Michigan, Ann Arbor, MI (United States); SLAC National Accelerator Lab., Menlo Park, CA (United States)
  28. Univ. of Manchester, Manchester (United Kingdom)
Publication Date:
OSTI Identifier:
1201363
Report Number(s):
BNL--108183-2015-JA
Journal ID: ISSN 0035-8711; KA2301020
Grant/Contract Number:
SC00112704
Type:
Accepted Manuscript
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Volume: 449; Journal Issue: 1; Conference: Naples (Italy), 3-5 Jun 2014; Journal ID: ISSN 0035-8711
Publisher:
Royal Astronomical Society
Research Org:
Brookhaven National Laboratory (BNL), Upton, NY (United States)
Sponsoring Org:
USDOE Office of Science (SC), High Energy Physics (HEP) (SC-25)
Country of Publication:
United States
Language:
English
Subject:
79 ASTRONOMY AND ASTROPHYSICS galaxies: magellanic clouds; galaxies: stellar content; stars: statistics