2015/04/06 by Timothy P. Ellsworth-Bowers, Jason Glenn, Allyssa Riley +7 · 18 citations
Physics and Astronomy · #Astronomy and Astrophysical Research #Astrophysics and Star Formation Studies #Formalism (music) #Galactic plane #Galaxies: Formation, Evolution, Phenomena #Galaxy #High mass #Initial mass function #Interstellar medium #Molecular cloud #Population #Spectral index #Stellar population #astro-ph.GA
paper · pdf · doi:10.1088/0004-637x/805/2/157
published in The Astrophysical Journal 805(2), 157 (IOP Publishing) · Accepted for publication in ApJ; 32 pages, 21 figures
arxiv created 2015/04/06 · openalex publication_date 2015/05/29 · arxiv updated 2015/06/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/06
We use the distance probability density function formalism of Ellsworth-Bowers et al. to derive physical properties for the collection of 1,710 Bolocam Galactic Plane Survey (BGPS) version 2 sources with well-constrained distance estimates. To account for Malmquist bias, we estimate that the present sample of BGPS sources is 90% complete above and 50% complete above . The mass distributions for the entire sample and astrophysically motivated subsets are generally fitted well by a lognormal function, with approximately power-law distributions at high mass. Power-law behavior emerges more clearly when the sample population is narrowed in heliocentric distance (power-law index for sources nearer than 6.5 kpc and for objects between 2 and 10 kpc). The high-mass power-law indices are generally for various subsamples of sources, intermediate between that of giant molecular clouds and the stellar initial mass function. The fit to the entire sample yields a high-mass power-law . Physical properties of BGPS sources are consistent with large molecular cloud clumps or small molecular clouds, but the fractal nature of the dense interstellar medium makes it difficult to map observational categories to the dominant physical processes driving the observed structure. The face-on map of the Galactic disk's mass surface density based on BGPS dense molecular cloud structures reveals the high-mass star-forming regions W43, W49, and W51 to be prominent mass concentrations in the first quadrant. Furthermore, we present a 0.25 kpc resolution map of the dense gas mass fraction across the Galactic disk that peaks around 5%.