Gas Kinematics and Star Formation in the Filamentary IRDC G34.43+0.24
Abstract
We performed a multiwavelength study toward infrared dark cloud (IRDC) G34.43+0.24. New maps of 13CO J=1-0 and C18O J=1-0 were obtained from the Purple Mountain Observatory (PMO) 13.7 m radio telescope. At 8 um (Spitzer - IRAC), IRDC G34.43+0.24 appears to be a dark filament extended by 18 arcmin along the north-south direction. Based on the association with the 870 um and C18O J=1-0 emission, we suggest that IRDC G34.43+0.24 should not be 18 arcmin in length, but extend by 34 arcmin. IRDC G34.43+0.24 contains some massive protostars, UC H II regions, and infrared bubbles. The spatial extend of IRDC G34.43+0.24 is about 37 pc assuming a distance of 3.7 kpc. IRDC G34.43+0.24 has a linear mass density of 1.6*103 Msun pc-1, which is roughly consistent with its critical mass to length ratio. The turbulent motion may help stabilizing the filament against the radial collapse. Both infrared bubbles N61 and N62 show a ringlike structure at 8 um. Particularly, N61 has a double-shell structure, which has expanded into IRDC G34.43+0.24. The outer shell is traced by 8 um and 13CO J=1-0 emission, while the inner shell is traced by 24 um and 20 cm emission. We suggest that the outer shell (9.9*105 yr) is created by the expansion of H II region G34.172+0.175, while the inner shell (4.1-6.3*105 yr) may be produced by the energetic stellar wind of its central massive star. From GLIMPSE I catalog, we selected some Class I sources with an age of 105 yr. These Class I sources are clustered along the filamentary molecular cloud.
Turn this paper into a lesson
ArcXiv compiles a structured reading guide from this paper's metadata: plain-English importance, contributions, prerequisite concepts, which sections to read first, flashcards, and a quiz. Grounded in the abstract, never invented.