Neutral hydrogen absorption in the quasar 3C 268.4 - Possible evidence for galactic halo clouds

Abstract

view Abstract Citations (5) References (21) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS Neutral hydrogen absorption in the quasar 3C 268.4 : possible evidence for galactic halo clouds. Haschick, A. D. ; Crane, P. C. ; Baan, W. A. Abstract A number of suggestions have been made concerning the origin of absorption lines present in the spectra of quasars, taking into account also the possibility that the absorbing material exists in unrelated objects along the line of sight to the quasar. Searches have, therefore, been conducted for neutral hydrogen absorption in four of the quasar-galaxy pairs published by Burbidge et al. (1971). The present investigation had the objective to reexamine with greater sensitivity certain of the quasar-galaxy pair in the list of Burbidge et al. as part of a larger survey of quasar-galaxy pairs. The results are presented of a long integration on the neutral hydrogen spectrum of 3C 268.4. Two absorbing dips are present in the spectrum at widely separate velocities. These high velocities seem to indicate that the absorbing clouds are in the halo region rather than the disk of the nearby galaxy NGC 4138. It is suggested that these clouds are similar to the high-velocity clouds detected in the Milky Way Galaxy. Publication: The Astrophysical Journal Pub Date: June 1983 DOI: 10.1086/184052 Bibcode: 1983ApJ...269L..43H Keywords: Absorption Spectra; Astronomical Spectroscopy; Hydrogen Clouds; Neutral Gases; Quasars; Radio Galaxies; Centimeter Waves; Line Spectra; Radial Velocity; Radiant Flux Density; Astrophysics full text sources ADS | data products NED (5) SIMBAD (2)