Formaldehyde in the rho Ophiuchi dark cloud

Journal Article · Sat Nov 01 04:00:00 EST 1975 · Astrophysical Journal

DOI:https://doi.org/10.1086/181972· OSTI ID:4108386

Myers, P. C.; Ho, P. T. P.

The 6-cm transition of H$sub 2$CO was mapped in absorption over a region approx.1degreetimesapprox.1degree with 6' resolution toward the rho Oph dark cloud. The distribution of H$sub 2$CO column density agrees well with the extinction due to dust. At least three regions of high H$sub 2$CO concentration can be identifed. Two regions of reduced H$sub 2$CO column density coincide with regions of carbon recombination-line emission, reflection nebulosity, and concentration of infrared sources. The most likely mechanisms of line intensity reduction are increased excitation temperature, due to electron collisions, and reduced column density, due to destructive C$sup +$ collisions. Both effects are associated with the observed C ii regions (s). A north-south velocity gradient of approx.0.5 km s$sup -1$ pc$sup -1$ is observed, which is probably not sufficient to stabilize the cloud against large-scale gravitational collapse. (AIP)

• Research Organization: Massachusetts Institute of Technology, Research Laboratory of Electronics and Department of Physics
• Sponsoring Organization: USDOE
• NSA Number: NSA-33-018205
• OSTI ID: 4108386
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Vol. 202; ISSN 0004-637X
• Publisher: Institute of Physics (IOP)
• Country of Publication: United States
• Language: English

Related Subjects

*INTERSTELLAR SPACE-- FORMALDEHYDE
640105* --Physics Research--Astrophysics & Cosmology-- Galaxies
CARBON
GRAVITATIONAL COLLAPSE
N56500* --Physics (Astrophysics & Cosmology)--Galaxies
RADIOWAVE RADIATION
RECOMBINATION