view Abstract Citations (118) References (39) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Atomic and molecular observations of the rho Ophiuchi dark cloud. Myers, P. C. ; Ho, P. T. P. ; Schneps, M. H. ; Chin, G. ; Pankonin, V. ; Winnberg, A. Abstract The density and temperature structure, kinematics, and chemistry of the dark cloud complex near Rho Oph are studied using maps of microwave spectral-line parameters for lines of H, OH, H2CO, and CO. The spatial extent of each cloud fragment as observed in a particular line is analyzed along with the variation of line width with spatial extent and the correlations among the densities of the observed species. The results obtained indicate that: (1) the observed species have spatial extents ranging from about 0.1 to 6 pc; (2) on a scale of less than about 1 pc, the cloud is organized into two main fragments; (3) the gas density varies within the fragments as the -1.3 power of radial distance; (4) the line width of a given species increases with its spatial extent, suggesting radial contraction of the fragments with a velocity of about half that expected in free fall; and (5) the abundances of H2CO, OH, and CO are similar to those in other large dark clouds and are strongly correlated with extinction. Publication: The Astrophysical Journal Pub Date: March 1978 DOI: 10.1086/155976 Bibcode: 1978ApJ...220..864M Keywords: Absorption Spectra; Abundance; Atomic Spectra; Interstellar Gas; Microwave Spectra; Molecular Spectra; Ammonia; Carbon Monoxide; Formaldehyde; Hydrogen; Hydroxyl Emission; Infrared Spectra; Astronomy; Dark Clouds:Microwave Spectra; Dark Clouds:Molecules full text sources ADS | data products SIMBAD (3)