SMASHing the LMC

Mapping a Ring-like Stellar Overdensity in the LMC Disk

Yumi Choi, David L. Nidever, Knut Olsen, Gurtina Besla, Robert D. Blum, Dennis F Zaritsky, Maria Rosa L. Cioni, Roeland P. Van Der Marel, Eric F. Bell, L. Clifton Johnson, A. Katherina Vivas, Alistair R. Walker, Thomas J.L. De Boer, Noelia E.D. Noël, Antonela Monachesi, Carme Gallart, Matteo Monelli, Guy S. Stringfellow, Pol Massana, David Martinez-Delgado & 1 others Ricardo R. Muñoz

Research output: Contribution to journalArticle

3 Citations (Scopus)

Abstract

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.

Original languageEnglish (US)
Article number125
JournalAstrophysical Journal
Volume869
Issue number2
DOIs
StatePublished - Dec 20 2018

Fingerprint

Magellanic clouds
rings
formation mechanism
collision
spiral wrapping
history
energy
stellar structure
main sequence stars
star clusters
clumps
dark energy
encounters
halos
histories
stars
collisions
radii
products
young

Keywords

  • galaxies: dwarf
  • galaxies: interactions
  • galaxies: structure
  • Magellanic Clouds

ASJC Scopus subject areas

  • Astronomy and Astrophysics
  • Space and Planetary Science

Cite this

SMASHing the LMC : Mapping a Ring-like Stellar Overdensity in the LMC Disk. / Choi, Yumi; Nidever, David L.; Olsen, Knut; Besla, Gurtina; Blum, Robert D.; Zaritsky, Dennis F; 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, Carme; Monelli, Matteo; Stringfellow, Guy S.; Massana, Pol; Martinez-Delgado, David; Muñoz, Ricardo R.

In: Astrophysical Journal, Vol. 869, No. 2, 125, 20.12.2018.

Research output: Contribution to journalArticle

Choi, Y, Nidever, DL, Olsen, K, Besla, G, Blum, RD, Zaritsky, DF, Cioni, MRL, Van Der Marel, RP, Bell, EF, Johnson, LC, Vivas, AK, Walker, AR, De Boer, TJL, Noël, NED, Monachesi, A, Gallart, C, Monelli, M, Stringfellow, GS, Massana, P, Martinez-Delgado, D & Muñoz, RR 2018, 'SMASHing the LMC: Mapping a Ring-like Stellar Overdensity in the LMC Disk', Astrophysical Journal, vol. 869, no. 2, 125. https://doi.org/10.3847/1538-4357/aaed1f
Choi, Yumi ; Nidever, David L. ; Olsen, Knut ; Besla, Gurtina ; Blum, Robert D. ; Zaritsky, Dennis F ; 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, Carme ; Monelli, Matteo ; Stringfellow, Guy S. ; Massana, Pol ; Martinez-Delgado, David ; Muñoz, Ricardo R. / SMASHing the LMC : Mapping a Ring-like Stellar Overdensity in the LMC Disk. In: Astrophysical Journal. 2018 ; Vol. 869, No. 2.
@article{6551c82b2c0a4d32a8102bb2a5762e3a,
title = "SMASHing the LMC: Mapping a Ring-like Stellar Overdensity in the LMC Disk",
abstract = "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.",
keywords = "galaxies: dwarf, galaxies: interactions, galaxies: structure, Magellanic Clouds",
author = "Yumi Choi and Nidever, {David L.} and Knut Olsen and Gurtina Besla and Blum, {Robert D.} and Zaritsky, {Dennis F} and Cioni, {Maria Rosa L.} and {Van Der Marel}, {Roeland P.} and Bell, {Eric F.} and Johnson, {L. Clifton} and Vivas, {A. Katherina} and Walker, {Alistair R.} and {De Boer}, {Thomas J.L.} and No{\"e}l, {Noelia E.D.} and Antonela Monachesi and Carme Gallart and Matteo Monelli and Stringfellow, {Guy S.} and Pol Massana and David Martinez-Delgado and Mu{\~n}oz, {Ricardo R.}",
year = "2018",
month = "12",
day = "20",
doi = "10.3847/1538-4357/aaed1f",
language = "English (US)",
volume = "869",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",

}

TY - JOUR

T1 - SMASHing the LMC

T2 - Mapping a Ring-like Stellar Overdensity in the LMC Disk

AU - Choi, Yumi

AU - Nidever, David L.

AU - Olsen, Knut

AU - Besla, Gurtina

AU - Blum, Robert D.

AU - Zaritsky, Dennis F

AU - Cioni, Maria Rosa L.

AU - Van Der Marel, Roeland P.

AU - Bell, Eric F.

AU - Johnson, L. Clifton

AU - Vivas, A. Katherina

AU - Walker, Alistair R.

AU - De Boer, Thomas J.L.

AU - Noël, Noelia E.D.

AU - Monachesi, Antonela

AU - Gallart, Carme

AU - Monelli, Matteo

AU - Stringfellow, Guy S.

AU - Massana, Pol

AU - Martinez-Delgado, David

AU - Muñoz, Ricardo R.

PY - 2018/12/20

Y1 - 2018/12/20

N2 - 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.

AB - 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.

KW - galaxies: dwarf

KW - galaxies: interactions

KW - galaxies: structure

KW - Magellanic Clouds

UR - http://www.scopus.com/inward/record.url?scp=85059849457&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85059849457&partnerID=8YFLogxK

U2 - 10.3847/1538-4357/aaed1f

DO - 10.3847/1538-4357/aaed1f

M3 - Article

VL - 869

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

M1 - 125

ER -