English

Distances to molecular clouds in the second Galactic quadrant

Astrophysics of Galaxies 2021-02-03 v1

Abstract

We present distances to 76 medium-sized molecular clouds and an extra large-scale one in the second Galactic quadrant (104.75<l<150.25104.75^\circ <l<150.25^\circ and b<5.25|b|<5.25^\circ), 73 of which are accurately measured for the first time. Molecular cloud samples are drawn from ll-bb-VV space (95<VLSR<25-95 < V_{\rm LSR}< 25 \kms) with the density-based spatial clustering of applications with noise (DBSCAN) algorithm, and distances are measured with the background-eliminated extinction-parallax (BEEP) method using extinctions and Gaia DR2 parallaxes. The range of measured distances to 76 molecular clouds is from 211 to 2631 pc, and the extra large-scale molecular cloud appears to be a coherent structure at about 1 kpc, across about 40\deg\ (\sim700 pc) in the Galactic longitude.

Keywords

Cite

@article{arxiv.2012.09500,
  title  = {Distances to molecular clouds in the second Galactic quadrant},
  author = {Qing-Zeng Yan and Ji Yang and Yan Sun and Yang Su and Ye Xu and Hongchi Wang and Xin Zhou and Chen Wang},
  journal= {arXiv preprint arXiv:2012.09500},
  year   = {2021}
}

Comments

10 pages, 9 figures, accepted for pulication in A&A

R2 v1 2026-06-23T21:02:37.313Z