AN ORPHAN NO LONGER? DETECTION OF THE SOUTHERN ORPHAN STREAM AND A CANDIDATE PROGENITOR

作者：Grillmair Carl J^*; Hetherington Lauren; Carlberg Raymond G; Willman Beth

来源：Astrophysical Journal Letters, 2015, 812(2): L26.

DOI：10.1088/2041-8205/812/2/L26

• Galaxy: halo
• Galaxy: structure

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 decl. of -38 degrees, bringing the total known length of the Orphan Stream to 108 degrees. We find a slight offset or "S" shape in the stream at delta similar or equal to -14 degrees that would be consistent with the transition from leading to trailing arms. This coincides with a moderate concentration of 137 +/- 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.

• 出版日期2015-10-20