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 MAgellanic Stellar History (SMASH), SMASH 1 is a compact (r(h) 9.1(-3.4)(+5.9)pc) and very low luminosity (M-V = -1.0 +/- 0.9, L-V = 10(2.3 +/- 0.4) L-circle dot) 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 ([Fe/H] = -2.2) and old (13 Gyr) isochrone located at a distance modulus of similar to 18.8, i.e., a distance of similar to 57 kpc. Situated at 11 degrees.3 from the LMC in projection, its three-dimensional distance from the Cloud is similar to 13 kpc, consistent with a connection to the LMC, whose tidal radius is at least 16 kpc. 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 less than or similar to 19 pc at this distance from the LMC, and smaller than the system's extent on the sky. Its low luminosity and apparent high ellipticity (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.The Milky Way System" of the German Research Foundation (DFB) [Sonderforschungsbereich (SFB) 881]; U.S. Department of Energy; National Science Foundation; Ministry of Education and Science (Spain); Science and Technology Facilities Council (UK); Higher Education Funding Council (England); National Center for Supercomputing Applications (Brazil); Kavli Institute for Cosmological Physics (Brazil); Financiadora de Estudos e Projetos (Brazil); Fundacao Carlos Chagas Filho de Amparo a Pesquisa (Brazil); Conselho Nacional de Desenvolvimento Cientfico e Tecnologico (Brazil); Ministerio da Ciencia e Tecnologia (Brazil); German Research Foundation; Argonne National Lab; Robert Martin Ayers Sciences Fund; University of California Santa Cruz; University of Cambridge; Centro de Investigaciones Energeticas; Medioambientales y Tecnologicas-Madrid; University of Chicago; University College London; DES-Brazil consortium; University of Edinburgh; ETH-Zurich; University of Illinois at Urbana-Champaign; Institut de Ciencies de l'Espai; Institut de Fisica d'Altes Energies; Lawrence Berkeley National Lab; Ludwig-Maximilians Universitat; University of Michigan; National Optical Astronomy Observatory; University of Nottingham; Ohio State University; University of Pennsylvania; University of Portsmouth; SLAC National Lab; Stanford University; University of Sussex; Texas AM University; [DP150100862]This item from the UA Faculty Publications collection is made available by the University of Arizona with support from the University of Arizona Libraries. If you have questions, please contact us at repository@u.library.arizona.edu