2014/03/31 by Sarah E. Ragan, S. E. Ragan, Thomas Henning +11 · 8 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Extinction (optical mineralogy) #Galactic corona #Galactic plane #Galactic tide #Galaxies: Formation, Evolution, Phenomena #Milky Way #Molecular cloud #Spiral galaxy #Star formation #astro-ph.GA
paper · pdf · doi:10.1051/0004-6361/201423401
published as A&A 568, A73 (2014) · 22 pages, 16 figures. Accepted to A&A
openalex publication_date 2014/06/28 · arxiv created 2014/07/01 · arxiv updated 2014/09/05 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
Throughout the Milky Way, molecular clouds typically appear filamentary, and mounting evidence indicates that this morphology plays an important role in star formation. What is not known is to what extent the dense filaments most closely associated with star formation are connected to the surrounding diffuse clouds up to arbitrarily large scales. How are these cradles of star formation linked to the Milky Way’s spiral structure? Using archival Galactic plane survey data, we have used multiple datasets in search of large-scale, velocity-coherent filaments in the Galactic plane. In this paper, we present our methods employed to identify coherent filamentary structures first in extinction and confirmed using Galactic Ring Survey data. We present a sample of seven giant molecular filaments (GMFs) that have lengths on the order of ~100 pc, total masses of 104–105 M⊙, and exhibit velocity coherence over their full length. The GMFs we study appear to be inter-arm clouds and may be the Milky Way analogs to spurs observed in nearby spiral galaxies. We find that between 2 and 12% of the total mass (above ~1020 cm-2) is “dense” (above 1022 cm-2), where filaments near spiral arms in the Galactic midplane tend to have higher dense gas mass fractions than those further from the arms.