Evidence of Hubble Flow-like Motion of Young Stellar Populations away from the Perseus Arm
Abstract
In this Letter we present evidence of the coherent outward motion of a sample of young stars (t < 30 Myr) in the Perseus Arm, whose apparent origin is located in the vicinity of the W3/W4/W5 complex. Using astrometric and photometric data from the Gaia Data Release 2 catalog of an 8◦ radius field centered near W4, we selected a sample of young intermediate- to high-mass star candidates. The sample is limited to sources with parallax uncertainties below 20% and Bayesian distance estimates within 1800 and 3100 pc. The selection includes embedded stellar populations as well as young open clusters. Projected velocities derived from perspective-corrected proper motions clearly suggest that the young star population emerged from the Perseus Arm, with a possible convergence zone near W3/W4/W5 region, tracing a front that expands away at a rate of about 15 {km} {{{s}}}-1 {kpc}}-1.
- Publication:
-
The Astrophysical Journal
- Pub Date:
- January 2019
- DOI:
- 10.3847/2041-8213/aafb06
- arXiv:
- arXiv:1812.11102
- Bibcode:
- 2019ApJ...871L..12R
- Keywords:
-
- Galaxy: kinematics and dynamics;
- open clusters and associations: general;
- stars: kinematics and dynamics;
- stars: massive;
- Astrophysics - Astrophysics of Galaxies;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 6 pages, 5 figures, Accepted for publication, December 27, 2018