A direct measure of the Gunn-Peterson effect at Z = 3 - Limits on the baryon density of the intergalactic medium at high redshifts

Abstract

view Abstract Citations (41) References (23) Co-Reads Similar Papers Volume Content Graphics Metrics Export Citation NASA/ADS A Direct Measure of the Gunn-Peterson Effect at Z = 3: Limits on the Baryon Density of the Intergalactic Medium at High Redshifts Giallongo, Emanuele ; Cristiani, Stefano ; Trevese, Dario Abstract A measure of the average depression between Lyman absorption lines in the spectrum of the quasar Q2126 - 158 (Z_em_ = 3.27) is presented. Regions free of absorption lines, in the Lyα forest of the quasar, are selected on the basis of high-resolution data (FWHM > 0.2 A). We have extended the wavelength interval from 7000 to 8500 A, by means of data taken at low resolution, to obtain a more reliable evaluation of the continuum shape redward of the Lyα emission, and we describe the procedure adopted to define the continuum level. We obtain a best estimate of τ = 0.013 +/- 0.026 at <z> = 3. Constraints on the baryon density of the intergalactic medium are discussed. Publication: The Astrophysical Journal Pub Date: October 1992 DOI: 10.1086/186564 Bibcode: 1992ApJ...398L...9G Keywords: Absorption Spectra; Baryons; Intergalactic Media; Quasars; Red Shift; Astronomical Spectroscopy; Lyman Alpha Radiation; Astrophysics; COSMOLOGY: OBSERVATIONS; GALAXIES: INTERGALACTIC MEDIUM; GALAXIES: QUASARS: GENERAL full text sources ADS | data products NED (1)