Serendipitous discovery of a thin stellar stream near the Galactic bulge in the Pan-STARRS1 3π Survey.
Abstract
We report the discovery of a thin stellar stream found in Pan-STARRS1 photometry near the Galactic bulge in the constellation of Ophiuchus. It appears as a coherent structure in the colour-selected stellar density maps produced to search for tidal debris around nearby globular clusters. The stream is exceptionally short and narrow; it is about 2.5° long and 6 arcmin wide in projection. The colour-magnitude diagram of this object, which harbours a blue horizontal-branch, is consistent with an old and relatively metal-poor population ([Fe/H] ∼-1.3) located 9.5 ± 0.9 kpc away at (l, b) ∼ (5°, +32°), and 5.0 ± 1.0 kpc from the Galactic centre. These properties argue for a globular cluster as progenitor. The finding of such a prominent, nearby stream suggests that many streams could await discovery in the more densely populated regions of our Galaxy.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- September 2014
- DOI:
- 10.1093/mnrasl/slu089
- arXiv:
- arXiv:1405.6645
- Bibcode:
- 2014MNRAS.443L..84B
- Keywords:
-
- surveys;
- globular clusters: general;
- Galaxy: halo;
- Galaxy: structure;
- Astrophysics - Astrophysics of Galaxies
- E-Print:
- 5 pages, 3 figures. MNRAS, in press