The absorption spectrum of the quasar PHL 1222

Journal Article · Sun Aug 01 04:00:00 EDT 1976 · Astrophys. J., Lett.; (United States)

DOI:https://doi.org/10.1086/182199· OSTI ID:7337300

Williams, R E; Weymann, R J

Intermediate dispersion spectroscopy of the quasar PHL 1222 (z/sub em/=1.91) has revealed the presence of C II and Si II absorption lines arising from the ground state in a system with z/sub abs/=1.934. The absence of absorption lines arising from the exciting fine-structure levels of these ions enables limits to be placed on the physical conditions in the absorption cloud. The gas must have a density n/sub e/approximately-less-than15 cm/sup -3/, and must be at least 4 x 10/sup 5/ pc from the continuum source. If inward gravitational acceleration is responsible for the existence of the absorption system with z/sub abs/>z/sub em/, and if the cosmological distance of the QSO is adopted, then the mass producing the acceleration must be approximately-greater-than3 x 10/sup 14/ M/sub sun/. We take this as suggestive evidence that the z/sub abs/=1.934 system represents an intergalactic gas cloud moving in a cluster of galaxies which contains a quasar. In addition, we have discovered three new redshift systems based upon the C iv doublet, for which z/sub abs/very-much-less-thanz/sub em/. (AIP)

• Research Organization: Steward Observatory, University of Arizona
• OSTI ID: 7337300
• Journal Information: Astrophys. J., Lett.; (United States), Journal Name: Astrophys. J., Lett.; (United States) Vol. 207:3; ISSN AJLEA
• Country of Publication: United States
• Language: English

Related Subjects

640103* -- Astrophysics & Cosmology-- Quasi-Stellar
Radio
& X-Ray Sources-- (-1987)
71 CLASSICAL AND QUANTUM MECHANICS
GENERAL PHYSICS
ABSORPTION SPECTRA
CHEMICAL COMPOSITION
COSMIC RADIO SOURCES
DOPPLER EFFECT
GALAXY CLUSTERS
GRAVITATIONAL COLLAPSE
QUASARS
SPECTRA