Exploring the Very Extended Low-surface-brightness Stellar Populations of the Large Magellanic Cloud with SMASH
| Autor: | Dennis Zaritsky, Roeland P. van der Marel, Maria-Rosa L. Cioni, Guy S. Stringfellow, Matteo Monelli, Carme Gallart, David L. Nidever, Nicolas F. Martin, A. Katherina Vivas, Gurtina Besla, Robert Blum, Abhijit Saha, Noelia E. D. Noël, Yumi Choi, David Martínez-Delgado, Pol Massana, Steven R. Majewski, You-Hua Chu, Eric F. Bell, Alistair R. Walker, Antonela Monachesi, Blair C. Conn, Ricardo R. Muñoz, Catherine C. Kaleida, Thomas J. L. de Boer, Knut Olsen |
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| Přispěvatelé: | University of Arizona, Observatoire astronomique de Strasbourg (ObAS), Université de Strasbourg (UNISTRA)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS), Chimie, Modélisation et Imagerie pour la Biologie [Orsay], Université Paris-Sud - Paris 11 (UP11)-Institut Curie [Paris]-Institut National de la Santé et de la Recherche Médicale (INSERM)-Institut de Chimie du CNRS (INC)-Centre National de la Recherche Scientifique (CNRS), Instituto de Astrofisica de Canarias (IAC) |
| Rok vydání: | 2019 |
| Předmět: |
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] |
| Zdroj: | The Astrophysical Journal The Astrophysical Journal, American Astronomical Society, 2019, 874 (2), pp.118. ⟨10.3847/1538-4357/aafaf7⟩ |
| ISSN: | 1538-4357 0004-637X 1538-3881 0067-0049 1748-0221 1538-3873 |
| DOI: | 10.3847/1538-4357/aafaf7 |
| Popis: | 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. Comment: 9 pages, 5 figues, 1 table, submitted to ApJ |
| Databáze: | OpenAIRE |
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