Bibcode
Choi, Y.; Nidever, David L.; Olsen, Knut; Besla, Gurtina; Blum, Robert D.; Zaritsky, Dennis; Cioni, Maria-Rosa L.; van der Marel, Roeland P.; Bell, Eric F.; Johnson, L. Clifton; Vivas, A. Katherina; Walker, Alistair R.; de Boer, Thomas J. L.; Noël, Noelia E. D.; Monachesi, Antonela; Gallart, C.; Monelli, M.; Stringfellow, Guy S.; Massana, Pol; Martinez-Delgado, David; Muñoz, Ricardo R.
Bibliographical reference
The Astrophysical Journal, Volume 869, Issue 2, article id. 125, 12 pp. (2018).
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12
2018
Journal
Citations
40
Refereed citations
37
Description
We explore the stellar structure of the Large Magellanic Cloud (LMC)
disk using data from the Survey of the MAgellanic Stellar History and
the Dark Energy Survey. We detect a ring-like stellar overdensity in the
red clump star count map at a radius of ∼6° (∼5.2 kpc at the
LMC distance) that is continuous over ∼270° in position angle
and is only limited by the current data coverage. The overdensity shows
an amplitude up to 2.5 times higher than that of the underlying smooth
disk. This structure might be related to the multiple arms found by de
Vaucouleurs. We find that the overdensity shows spatial correlation with
intermediate-age star clusters, but not with young (<1 Gyr)
main-sequence stars, indicating the stellar populations associated with
the overdensity are intermediate in age or older. Our findings on the
LMC overdensity can be explained by either of two distinct formation
mechanisms of a ring-like overdensity: (1) the overdensity formed out of
an asymmetric one-armed spiral wrapping around the LMC main body, which
is induced by repeated encounters with the Small Magellanic Cloud (SMC)
over the last Gyr, or (2) the overdensity formed very recently as a
tidal response to a direct collision with the SMC. Although the measured
properties of the overdensity alone cannot distinguish between the two
candidate scenarios, the consistency with both scenarios suggests that
the ring-like overdensity is likely a product of tidal interaction with
the SMC, but not with the Milky Way halo.
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