The systemic redshift of the quasar 1331 + 170

Abstract

Infrared spectra covering the 1.6- and 2-micron regions of the quasar 1331 + 170, redshift z = 2.09, were obtained with the CGS4 spectrometer at the UK Infrared Telescope. These spectra show redshifted H-alpha, H-beta, and (O-III) lines. The redshifts of the forbidden lines are similar to the low-ionization lines measured at optical wavelengths but are significantly higher than the high-ionization-line redshift. Thus, the low-ionization lines are likely to provide a reliable estimate for the systematic redshift in this object, and the high-ionization material is therefore flowing out from, or into, the quasar and is subject to some obscuration.