SMASH 1: a very faint globular cluster disrupting in the outer reaches of the LMC?
We present the discovery of a very faint stellar system, SMASH 1, that is potentially a satellite of the Large Magellanic Cloud. Found within the Survey of the Ma gellanic Stellar History (SMASH), SMASH 1 is a compact ( ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn1.gif] $r_h=...
Saved in:
| Main Authors: | , , |
|---|---|
| Format: | Article (Journal) |
| Language: | English |
| Published: |
2016 October 6
|
| In: |
The astrophysical journal. Part 2, Letters
Year: 2016, Volume: 830, Issue: 1 |
| ISSN: | 2041-8213 |
| DOI: | 10.3847/2041-8205/830/1/L10 |
| Online Access: | Verlag, Volltext: http://dx.doi.org/10.3847/2041-8205/830/1/L10
|
| Author Notes: | Nicolas F. Martin, Valentin Jungbluth, David L. Nidever, Eric F. Bell, Gurtina Besla, Robert D. Blum, Maria-Rosa L. Cioni, Blair C. Conn, Catherine C. Kaleida, Carme Gallart, Shoko Jin, Steven R. Majewski, David Martinez-Delgado, Antonela Monachesi, Ricardo R. Muñoz, Noelia E.D. Noël, Knut Olsen, Guy S. Stringfellow, Roeland P. van der Marel, A. Katherina Vivas, Alistair R. Walker, and Dennis Zaritsky |
| Summary: | We present the discovery of a very faint stellar system, SMASH 1, that is potentially a satellite of the Large Magellanic Cloud. Found within the Survey of the Ma gellanic Stellar History (SMASH), SMASH 1 is a compact ( ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn1.gif] $r_h=9.1_-3.4^+5.9\,\mathrmpc$ ) and very low luminosity ( ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn2.gif] $M_V=-1.0\pm 0.9$ , ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn3.gif] $L_V=10^2.3\pm 0.4\,L_ødot $ ) stellar system that is revealed by its sparsely populated main sequence and a handful of red giant branch candidate member stars. The photometric properties of these stars are compatible with a metal-poor ( ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn4.gif] $[\mathrmFe/\rmH]=-2.2$ ) and old (13 Gyr) isochrone located at a distance modulus of ∼18.8, i.e., a distance of ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn5.gif] $\sim 57\,\mathrmkpc$ . Situated at 11.°3 from the LMC in projection, its three-dimensional distance from the Cloud is ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn6.gif] $\sim 13\,\mathrmkpc$ , consistent with a connection to the LMC, whose tidal radius is at least ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn7.gif] $16\,\mathrmkpc$ . Although the nature of SMASH 1 remains uncertain, its compactness favors it being a stellar cluster and hence dark-matter free. If this is the case, its dynamical tidal radius is only ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn8.gif] $\lesssim 19\,\mathrmpc$ at this distance from the LMC, and smaller than the system’s extent on the sky. Its low luminosity and apparent high ellipticity ( ##IMG## [http://ej.iop.org/images/2041-8205/830/1/L10/apjlaa40f0ieqn9.gif] $\epsilon =0.62_-0.21^+0.17$ ) with its major axis pointing toward the LMC may well be the tell-tale sign of its imminent tidal demise. |
|---|---|
| Item Description: | Gesehen am 30.10.2017 |
| Physical Description: | Online Resource |
| ISSN: | 2041-8213 |
| DOI: | 10.3847/2041-8205/830/1/L10 |