21 centimeter absorption at z=0.395 in the quasar 1229-021

Abstract

view Abstract Citations (28) References (17) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS 21 centimeter absorption at z = 0.395 in the quasar 1229-021. Brown, R. L. ; Spencer, R. E. Abstract The detection of redshifted neutral atomic hydrogen in absorption toward the quasar 1229-021 is reported. The line appears at 1018.231 MHz, corresponding to an absorption redshift of 0.394974; optical absorption lines of Mg II and Mg I have been found previously at this redshift in 1229-021. Since the emission redshift of 1229-021 is 1.038, the absorbing material, if ejected from the quasar, must have a velocity of ejection of about c/3 relative to the quasar, and the ratio of line width to ejection velocity, 0.000042, is the most extreme yet found in any quasar. Alternatively, if the absorption occurs in an unrelated cloud along the line of sight and if the Mg is confined to the same velocity structure as is the H I, then the optical Mg I absorption line must be heavily saturated, and the inferred Mg/H abundance ratio is nearly solar. Publication: The Astrophysical Journal Pub Date: May 1979 DOI: 10.1086/182950 Bibcode: 1979ApJ...230L...1B Keywords: Absorption Spectra; Hydrogen Clouds; Microwave Spectra; Quasars; Red Shift; Hydrogen Atoms; Line Spectra; Magnesium; Optical Emission Spectroscopy; Stellar Mass Ejection; Astronomy; Neutral Hydrogen:Quasars full text sources ADS | data products SIMBAD (1)