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Exploring the Very Extended Low-surface-brightness Stellar Populations of the Large Magellanic Cloud with SMASH
- Source :
- The Astrophysical Journal, The Astrophysical Journal, American Astronomical Society, 2019, 874 (2), pp.118. ⟨10.3847/1538-4357/aafaf7⟩
- Publication Year :
- 2019
-
Abstract
- We present the detection of very extended stellar populations around the Large Magellanic Cloud (LMC) out to R~21 degrees, or ~18.5 kpc at the LMC distance of 50 kpc, as detected in the Survey of the MAgellanic Stellar History (SMASH) performed with the Dark Energy Camera on the NOAO Blanco 4m Telescope. The deep (g~24) SMASH color magnitude diagrams (CMDs) clearly reveal old (~9 Gyr), metal-poor ([Fe/H]=-0.8 dex) main-sequence stars at a distance of 50 kpc. The surface brightness of these detections is extremely low with our most distant detection having 34 mag per arcsec squared in g-band. The SMASH radial density profile breaks from the inner LMC exponential decline at ~13-15 degrees and a second component at larger radii has a shallower slope with power-law index of -2.2 that contributes ~0.4% of the LMC's total stellar mass. In addition, the SMASH densities exhibit large scatter around our best-fit model of ~70% indicating that the envelope of stellar material in the LMC periphery is highly disturbed. We also use data from the NOAO Source catalog to map the LMC main-sequence populations at intermediate radii and detect a steep dropoff in density on the eastern side of the LMC (at R~8 deg) as well as an extended structure to the far northeast. These combined results confirm the existence of a very extended, low-density envelope of stellar material with disturbed shape around the LMC. The exact origin of this structure remains unclear but the leading options include a classical accreted halo or tidally stripped outer disk material.<br />Comment: 9 pages, 5 figues, 1 table, submitted to ApJ
- Subjects :
- 010504 meteorology & atmospheric sciences
Stellar mass
Astrophysics::High Energy Astrophysical Phenomena
FOS: Physical sciences
Astrophysics
Astrophysics::Cosmology and Extragalactic Astrophysics
01 natural sciences
law.invention
Telescope
law
0103 physical sciences
Astrophysics::Solar and Stellar Astrophysics
Surface brightness
Large Magellanic Cloud
010303 astronomy & astrophysics
ComputingMilieux_MISCELLANEOUS
Astrophysics::Galaxy Astrophysics
0105 earth and related environmental sciences
Physics
Local Group
Astronomy and Astrophysics
Astrophysics - Astrophysics of Galaxies
Stars
Space and Planetary Science
Astrophysics of Galaxies (astro-ph.GA)
Dark energy
Halo
Astrophysics::Earth and Planetary Astrophysics
[PHYS.ASTR]Physics [physics]/Astrophysics [astro-ph]
Subjects
Details
- ISSN :
- 15384357, 0004637X, 15383881, 00670049, 17480221, and 15383873
- Database :
- OpenAIRE
- Journal :
- The Astrophysical Journal
- Accession number :
- edsair.doi.dedup.....91cfd97144aadfd5c1f3d9009c7b6909
- Full Text :
- https://doi.org/10.3847/1538-4357/aafaf7