An Orphan No Longer? Detection of the Southern Orphan Stream and a Candidate Progenitor

Abstract

Using a shallow, two-color survey carried out with the Dark Energy Camera, we detect the southern, possibly trailing arm of the Orphan Stream. The stream is reliably detected to a declination of $-38^{\circ }$, bringing the total known length of the Orphan stream to $108^{\circ }$. We find a slight offset or "S" shape in the stream at $\delta \simeq -14^{\circ }$ that would be consistent with the transition from leading to trailing arms. This coincides with a moderate concentration of $137\pm 25$ stars (to $g=21.6$) that we consider a possible remnant of the Orphan progenitor. The position of this feature is in agreement with previous predictions.

4 pages, 4 figures, accepted for publication in the Astrophysical Journal Letters

References in corpus (7)

• The ACS Nearby Galaxy Survey Treasury IX. Constraining asymptotic giant branch evolution with old metal-poor galaxies
• Detection of a 63 Degree Cold Stellar Stream in the Sloan Digital Sky Survey
• An Orphan in the "Field of Streams"
• Detection of a 60 Degree-Long Dwarf Galaxy Debris Stream
• A 22 Degree Tidal Tail for Palomar 5
• Is Ursa Major II the Progenitor of the Orphan Stream?
• Tracing the Orphan Stream to 55 kpc with RR Lyrae Stars

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• On the Hunt for the Origins of the Orphan--Chenab Stream: Detailed Element Abundances with APOGEE and Gaia
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