A New Cold Stream near the Southern Galactic Pole
Zhao, Gang; Zhao, Jing-Kun; Yang, Yong; Xue, Xiang-Xiang; Ye, Xian-Hao
China
Abstract
We report the discovery of a cold stream near the southern Galactic pole (dubbed as SGP-S) detected in Gaia Early Data Release 3. The stream is at a heliocentric distance of ~9.5 kpc and spans nearly 58° by 0.°6 on sky. The color-magnitude diagram of SGP-S indicates an old and metal-poor (age ~12 Gyr, [M/H] ~ -2.0 dex) stellar population. The stream's surface brightness reaches an exceedingly low level of Σ G ≃ 36.2 mag arcsec-2. Neither extant globular clusters nor other known streams are associated with SGP-S.