Molecules in galaxies. I - CO observations in a spiral arm of M31

Abstract

view Abstract Citations (37) References (15) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Molecules in Galaxies. I. CO Observations in a Spiral Arm of M31 Ryden, B. S. ; Stark, A. A. Abstract A 4 x 20 arcmin spiral arm region of M31 is mapped in C-12O (J = 1-0), using the Bell Laboratories 7 m antenna. The emission is confined to an arm 1-2 kpc wide. The surface density of H2, averaged over the mapped region, is 2.2 solar masses/sq pc, projected onto the plane of the galaxy. On the outer edge of the arm, the CO shows a systematic velocity deviation of up to 30 km/s. The molecular gas is accelerated as it crosses the spiral arm. The CO spectra show both broad and narrow emission lines, with widths ranging from 8 to 44 km/s FWHM. At about one-fifth of the observed points, the spectra show double emission lines, with peak-to-peak separations of 12-47 km/s. The tendency for the emission lines to be double-peaked may be the result of rapid acceleration of the gas in cloud-cloud collisions. Publication: The Astrophysical Journal Pub Date: June 1986 DOI: 10.1086/164296 Bibcode: 1986ApJ...305..823R Keywords: Andromeda Galaxy; Astronomical Spectroscopy; Carbon Monoxide; Interstellar Gas; Radio Spectra; Astronomical Maps; Brightness Temperature; Emission Spectra; Spectral Line Width; Tables (Data); Astrophysics; GALAXIES: INDIVIDUAL MESSIER NUMBER: M31; INTERSTELLAR: MOLECULES full text sources ADS | data products SIMBAD (1) NED (1) Related Materials (5) Part 2: 1986AJ.....91..517R Part 3: 1986ApJ...310..660S Part 4: 1987AJ.....94...54K Part 5: 1987ApJ...322...64S Part 6: 1988ApJ...332..432P