A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3π Survey

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

Abstract

We present the discovery of a faint Milky Way satellite, Laevens 2/Triangulum II, found in the Panoramic Survey Telescope And Rapid Response System (Pan-STARRS 1) 3 pi imaging data and confirmed with follow-up wide-field photometry from the Large Binocular Cameras. The stellar system, with an absolute magnitude of M_V=-1.8 +/-0.5, a heliocentric distance of 30 +2/-2 kpc, and a half-mass radius of 34 +9/-8 pc, shows remarkable similarity to faint, nearby, small satellites such as Willman 1, Segue 1, Segue 2, and Bo\"otes II. The discovery of Laevens 2/Triangulum II further populates the region of parameter space for which the boundary between dwarf galaxies and globular clusters becomes tenuous. Follow-up spectroscopy will ultimately determine the nature of this new satellite, whose spatial location hints at a possible connection with the complex Triangulum-Andromeda stellar structures.

Citation

Laevens, B., Martin, N., Ibata, R., Rix, H., Bernard, E., Bell, E., …Waters, C. (2015). A New Faint Milky Way Satellite Discovered in the Pan-STARRS1 3π Survey. Astrophysical Journal Letters, 802(2), https://doi.org/10.1088/2041-8205/802/2/l18

• Journal Article Type: Article
• Acceptance Date: Mar 17, 2015
• Publication Date: Apr 1, 2015
• Deposit Date: Aug 3, 2015
• Publicly Available Date: Sep 3, 2015
• Journal: Astrophysical Journal Letters
• Print ISSN: 2041-8205
• Electronic ISSN: 2041-8213
• Publisher: American Astronomical Society
• Peer Reviewed: Peer Reviewed
• Volume: 802
• Issue: 2
• DOI: https://doi.org/10.1088/2041-8205/802/2/l18
• Keywords: Galaxies: dwarf, Galaxy: structure, Globular clusters: general, Local Group.
• Public URL: https://durham-repository.worktribe.com/output/1424519