Local Spiral Structure Traced by Red Clump Stars

Autor: Lin, Zehao, Xu, Ye, Hou, Ligang, Liu, Dejian, Li, Yingjie, Hao, Chaojie, Li, Jingjing, Bian, Shuaibo
Rok vydání: 2022
Předmět:
Druh dokumentu: Working Paper
DOI: 10.3847/1538-4357/ac67a6
Popis: Using the cross-matched data of Gaia EDR3 and the 2MASS Point Source Catalog, a sample of RC stars with parallax accuracies better than 20% is identified and used to reveal the nearby spiral pattern traced by old stars. As shown in the overdensity distribution of RC stars, there is an arc-like feature extended from $l~\sim$ 90$^\circ$ to $\sim$ 243$^\circ$, which passed close to the Sun. This feature is probably an arm segment traced by old stars, indicating the Galaxy potential in the vicinity of the Sun. By comparing to the spiral arms depicted by young objects, we found that there are considerable offsets between the two different components of Galactic spiral arms. The spiral arm traced by RC stars tends to have a larger pitch angle, hence a more loose wound pattern.
Comment: 10 pages, 6 figures, accepted for publication in ApJ
Databáze: arXiv