Extragalactic high-velocity clouds - VLA observations of the broad neutral hydrogen absorption in the radio galaxy 3C 293

Abstract

view Abstract Citations (24) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Extragalactic high-velocity clouds - VLA observations of the broad neutral hydrogen absorption in the radio galaxy 3C 293. Haschick, A. D. ; Baan, W. A. Abstract The radio galaxy 3C 293 has been mapped using the VLA at a resolution of 1.5 sec x 1.3 sec in order to study the broad (delta V = 480 km/s) neutral hydrogen absorption centered in its spectrum at a velocity of 13,500 km/s. The nuclear radio source, which is being absorbed, was resolved into a 2 sec east-west double source having slightly extended components. The spectral-line maps showed that one component of the absorbing material has a steep velocity gradient of approximately 83 km/s per arcsec across the double nuclear radio source, which is approximately equivalent to the gradient seen along the galaxy's major axis from optical emission lines. It is proposed that the absorbing gas associated with the strongest features is part of a rapidly rotating disk surrounding the nucleus of the galaxy. In addition to the disk component, six low-optical-depth, high-velocity features which are either redshifted or blueshifted by up to 300 km/s relative to the deepest absorption feature at 13,500 km/s are identified. These clouds are interpreted as indicating that gas is falling onto or being expelled from the nucleus of 3C 293. The data also indicates a stream of gas which is falling into the nuclear radio source and is probably fueling the central engine of the radio source. Publication: The Astrophysical Journal Pub Date: February 1985 DOI: 10.1086/162918 Bibcode: 1985ApJ...289..574H Keywords: Absorption Spectra; Astronomical Maps; Hydrogen; Neutral Gases; Radial Velocity; Radio Galaxies; Centimeter Waves; Extragalactic Radio Sources; Galactic Nuclei; Molecular Clouds; Optical Thickness; Astrophysics full text sources ADS | data products SIMBAD (1) NED (1)