English

Tidal tails around the outer halo globular clusters Eridanus and Palomar 15

Astrophysics of Galaxies 2018-01-25 v1

Abstract

We report the discovery of tidal tails around the two outer halo globular clusters, Eridanus and Palomar 15, based on gigi-band images obtained with DECam at the CTIO 4-m Blanco Telescope. The tidal tails are among the most remote stellar streams presently known in the Milky Way halo. Cluster members have been determined from the color-magnitude diagrams and used to establish the radial density profiles, which show, in both cases, a strong departure in the outer regions from the best-fit King profile. Spatial density maps reveal tidal tails stretching out on opposite sides of both clusters, extending over a length of \sim760 pc for Eridanus and \sim1160 pc for Palomar 15. The great circle projected from the Palomar 15 tidal tails encompasses the Galactic Center, while that for Eridanus passes close to four dwarf satellite galaxies, one of which (Sculptor) is at a comparable distance to that of Eridanus.

Keywords

Cite

@article{arxiv.1704.07690,
  title  = {Tidal tails around the outer halo globular clusters Eridanus and Palomar 15},
  author = {G. C. Myeong and Helmut Jerjen and Dougal Mackey and Gary S. Da Costa},
  journal= {arXiv preprint arXiv:1704.07690},
  year   = {2018}
}

Comments

6 pages, 3 figures, 1 table, ApJ Letters, accepted