The Astrophysical Journal Letters (Jan 2023)

DELVE 6: An Ancient, Ultra-faint Star Cluster on the Outskirts of the Magellanic Clouds

  • W. Cerny,
  • A. Drlica-Wagner,
  • T. S. Li,
  • A. B. Pace,
  • K. A. G. Olsen,
  • N. E. D. Noël,
  • R. P. van der Marel,
  • J. L. Carlin,
  • Y. Choi,
  • D. Erkal,
  • M. Geha,
  • D. J. James,
  • C. E. Martínez-Vázquez,
  • P. Massana,
  • G. E. Medina,
  • A. E. Miller,
  • B. Mutlu-Pakdil,
  • D. L. Nidever,
  • J. D. Sakowska,
  • G. S. Stringfellow,
  • J. A. Carballo-Bello,
  • P. S. Ferguson,
  • N. Kuropatkin,
  • S. Mau,
  • E. J. Tollerud,
  • A. K. Vivas,
  • DELVE Collaboration

DOI
https://doi.org/10.3847/2041-8213/aced84
Journal volume & issue
Vol. 953, no. 2
p. L21

Abstract

Read online

We present the discovery of DELVE 6, an ultra-faint stellar system identified in the second data release of the DECam Local Volume Exploration (DELVE) survey. Based on a maximum-likelihood fit to its structure and stellar population, we find that DELVE 6 is an old ( τ > 9.8 Gyr at 95% confidence) and metal-poor ([Fe/H] 9 Gyr) star cluster associated with the SMC, or one of fewer than two dozen ancient clusters associated with the LMC. Nonetheless, we cannot currently rule out the possibility that the system is a distant Milky Way halo star cluster.

Keywords