The origin of the quasi-stellar object absorption lines

1991 ◽  
Vol 377 ◽  
pp. 39 ◽  
Author(s):  
S. M. Viegas ◽  
R. B. Gruenwald
Keyword(s):  
Stellar Object ◽  
Absorption Lines

Absorption Lines in the Spectra of the QSO PKS 1448-232

1984 ◽  
Vol 5 (3) ◽  
pp. 355-359 ◽  
Author(s):  
Chen Jian-sheng ◽  
Donald C. Morton ◽  
Bruce A. Peterson ◽  
Alan E. Wright ◽  
David L. Jauncey
Keyword(s):  
Radio Source ◽  
Stellar Object ◽  
Absorption Lines ◽  
Ultraviolet Excess ◽  
Low Resolution ◽  
Optical Position

Savage et al. (1977) found that the radio source PKS 1448-232 coincided with a stellar object of about magnitude 16.4 having an ultraviolet excess. A low resolution spectrum obtained with the Anglo-Australian Telescope (AAT) confirmed this object as a QSO with zem = 2.22 and revealed many absorption lines short-ward of the La emission. Consequently this object was included in a programme of spectroscopy at intermediate resolution with the AAT to investigate QSO absorption lines. Savage et al. have given a finding chart with an optical position of 14h48m09s.3, −23°17′10″ (1950.0). The radio fluxes are 0.40 Jy at 2.7 GHz and 0.31 Jy at 5.0 GHz.

High‐Resolution Spectra of Intrinsic Absorption Lines in the Quasi‐stellar Object UM 675

1997 ◽  
Vol 478 (1) ◽  
pp. 80-86 ◽  
Author(s):  
Fred Hamann ◽  
Thomas A. Barlow ◽  
Vesa Junkkarinen ◽  
E. M. Burbidge
Keyword(s):  
High Resolution ◽  
Stellar Object ◽  
Absorption Lines ◽  
Intrinsic Absorption

Spectroscopy of the double quasars Q1343+266A, B: The relationship between galaxies and quasi-stellar object C IV absorption lines

1994 ◽  
Vol 437 ◽  
pp. L79 ◽  
Author(s):  
Arlin P. S. Crotts ◽  
Jill Bechtold ◽  
Yihu Fang ◽  
Robert C. Duncan
Keyword(s):  
Stellar Object ◽  
Absorption Lines ◽  
The Relationship

Time‐variable Intrinsic Absorption Lines in the Quasi‐stellar Object Q2343+125

1997 ◽  
Vol 478 (1) ◽  
pp. 87-93 ◽  
Author(s):  
Fred Hamann ◽  
Thomas A. Barlow ◽  
Vesa Junkkarinen
Keyword(s):  
Time Variable ◽  
Stellar Object ◽  
Absorption Lines ◽  
Intrinsic Absorption

scholarly journals Influence of Gravitational Lensing on Estimates of Ω in Neutral Hydrogen

1996 ◽  
Vol 173 ◽  
pp. 97-98
Author(s):  
Matthias Bartelmann ◽  
Abraham Loeb
Keyword(s):  
Observational Data ◽  
Gravitational Lensing ◽  
Column Density ◽  
Spiral Galaxies ◽  
Neutral Hydrogen ◽  
Absorption Lines ◽  
Gravitational Lenses ◽  
High Column

A wealth of observational data supports the commonly held view that damped Lyman-α (Lyα) absorption in QSO spectra is associated with neutral-hydrogen (HI) disks in spiral galaxies. Most of the HI probed by QSO absorption lines is traced by damped Lyα lines because of their high column densities, N > 1020 cm–2. The spiral galaxies hosting the HI disks can act as gravitational lenses on the QSOs. If the HI column density increases towards the center of the disks, as suggested by observations of local galaxies, the magnification bias preferentially selects for high column-density systems. The estimates of HI in damped Lyα systems can then systematically be distorted by gravitational lensing.

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