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

http://arxiv.org/abs/1509.07503


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.

Read this paper on arXiv…

C. Grillmair, L. Hetherington, R. Carlberg, et. al.
Mon, 28 Sep 15
31/67

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