Serendipitous discovery of a thin stellar stream near the Galactic bulge in the Pan-STARRS1 3π Survey

Bernard, E.J.; Ferguson, A.M.N.; Schlafly, E.F.; Abbas, M.; Bell, E.F.; Deacon, N.R.; Martin, N.F.; Rix, H.-W.; Sesar, B.; Slater, C.T.; Peñarrubia, J.; Wyse, R.F.G.; Burgett, W.S.; Chambers, K.C.; Draper, P.W.; Hodapp, K.W.; Kaiser, N.; Kudritzki, R.-P.; Magnier, E.A.; Metcalfe, N.; Morgan, J.S.; Price, P.A.; Tonry, J.L.; Wainscoat, R.J.; Waters, C.

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.

Citation

Bernard, E., Ferguson, A., Schlafly, E., Abbas, M., Bell, E., Deacon, N., …Waters, C. (2014). Serendipitous discovery of a thin stellar stream near the Galactic bulge in the Pan-STARRS1 3π Survey. Monthly Notices of the Royal Astronomical Society: Letters, 443(1), L84-L88. https://doi.org/10.1093/mnrasl/slu089

• Journal Article Type: Article
• Acceptance Date: Jun 6, 2014
• Publication Date: Sep 1, 2014
• Deposit Date: Jun 16, 2015
• Publicly Available Date: Jul 1, 2015
• Journal: Monthly Notices of the Royal Astronomical Society: Letters
• Electronic ISSN: 1745-3933
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 443
• Issue: 1
• Pages: L84-L88
• DOI: https://doi.org/10.1093/mnrasl/slu089
• Keywords: Surveys, Globular clusters: general, Galaxy: halo, Galaxy: structure.