scholarly journals Gaseous Galactic Halos and Quasi-stellar Object Absorption-Line Systems

1996 ◽  
Vol 469 ◽  
pp. 589 ◽  
Author(s):  
H. J. Mo ◽  
J. Miralda-Escude
Keyword(s):  
Absorption Line ◽  
Stellar Object ◽  
Galactic Halos

scholarly journals The Origin of Absorption Spectra in Quasi-Stellar Objects

1980 ◽  
Vol 92 ◽  
pp. 107-117 ◽  
Author(s):  
Ray J. Weymann
Keyword(s):  
Absorption Line ◽  
Absorption Spectra ◽  
Classification Scheme ◽  
Spectral Characteristics ◽  
Type A ◽  
Galactic Halos ◽  
Evolutionary Sequence ◽  
Rich Cluster ◽  
Stellar Objects ◽  
Quasi Stellar Objects

A classification scheme for QSO absorption line spectra is described which ascribes the origin of the lines to at least four mechanisms: (A) Explosive ejection of material at speeds up to 0.1 c. (B) Absorption by highly ionized material moving in a rich cluster in which the QSO is embedded. (C-1) Cosmologically distant intervening material with ‘normal’ abundances, probably associated with large galactic halos. (C-2) Cosmologically distant intervening material consisting of primordial uncondensed gas. Examples of each type of spectra are given and their ionization and other spectral characteristics discussed. The similarity between the development of novae spectra and a possible evolutionary sequence of the explosive ejecta of type A is striking and suggestive. Several difficulties and unsolved problems involving this scheme are noted. Finally, we speculate on the interpretation of two interesting objects (PKS 0237-23 and the ‘twin quasars’ 0957+56A,B) in the context of this scheme.

Absorption-Line Profiles in the Quasi-Stellar Object PHL 957

1972 ◽  
Vol 174 ◽  
pp. 237 ◽  
Author(s):  
Donald C. Morton ◽  
Winifred A. Morton
Keyword(s):  
Absorption Line ◽  
Stellar Object ◽  
Line Profiles

Imaging and Spectroscopy of Damped LY alpha Quasi-stellar Object Absorption-Line Clouds

1995 ◽  
Vol 451 ◽  
pp. 484 ◽  
Author(s):  
James D. Lowenthal ◽  
Craig J. Hogan ◽  
Richard F. Green ◽  
Bruce Woodgate ◽  
Adeline Caulet ◽  
...  
Keyword(s):  
Absorption Line ◽  
Stellar Object ◽  
Imaging And Spectroscopy

scholarly journals High-Redshift Superclustering of Quasi-stellar Object Absorption-Line Systems on 100 [ITAL]h[/ITAL][TSUP]−1[/TSUP] Mpc Scales

1996 ◽  
Vol 472 (2) ◽  
pp. L69-L72 ◽  
Author(s):  
Jean M. Quashnock ◽  
Daniel E. Vanden Berk ◽  
Donald G. York
Keyword(s):  
Absorption Line ◽  
High Redshift ◽  
Stellar Object

scholarly journals Large-scale Gas Dynamical Processes Affecting the Origin and Evolution of Gaseous Galactic Halos

1991 ◽  
Vol 144 ◽  
pp. 417-428
Author(s):  
Paul R. Shapiro
Keyword(s):  
Absorption Line ◽  
Large Scale ◽  
Galactic Halo ◽  
Galactic Disk ◽  
High Redshift ◽  
Cloud Formation ◽  
Galactic Halos ◽  
Origin And Evolution ◽  
Mhd Simulations ◽  
Halo Gas

Observations of galactic halo gas are consistent with an interpretation in terms of the galactic fountain model in which supernova heated gas in the galactic disk escapes into the halo, radiatively cools and forms clouds which fall back to the disk. The results of a new study of several large-scale gas dynamical effects which are expected to occur in such a model for the origin and evolution of galactic halo gas will be summarized, including the following: (1) nonequilibrium absorption line and emission spectrum diagnostics for radiatively cooling halo gas in our own galaxy, as well the implications of such absorption line diagnostics for the origin of quasar absorption lines in galactic halo clouds of high redshift galaxies; (2) numerical MHD simulations and analytical analysis of large-scale explosions and superbubbles in the galactic disk and halo; (3) numerical MHD simulations of halo cloud formation by thermal instability, with and without magnetic field; and (4) the effect of the galactic fountain on the galactic dynamo.

PKS 0528-250 - A neutral stellar object at Z = 2.812, with no emission lines and a rich absorption-line spectrum

1978 ◽  
Vol 221 ◽  
pp. L109 ◽  
Author(s):  
D. L. Jauncey ◽  
A. E. Wright ◽  
B. A. Peterson ◽  
J. J. Condon
Keyword(s):  
Absorption Line ◽  
Stellar Object ◽  
Emission Lines ◽  
Line Spectrum ◽  
No Emission

scholarly journals The global oxygen yield budget followed in hydrodynamic simulations

2015 ◽  
Vol 11 (A29B) ◽  
pp. 180-181
Author(s):  
Benjamin D. Oppenheimer ◽  
Robert A. Crain ◽  
Joop Schaye ◽  
Jason Tumlinson
Keyword(s):  
Black Hole ◽  
Absorption Line ◽  
Milky Way ◽  
Galactic Halos ◽  
Surprising Result ◽  
Hydrodynamic Simulations ◽  
Stellar Component ◽  
Circumgalactic Medium ◽  
Oxygen Yield ◽  
Non Equilibrium

AbstractWe present new EAGLE (“Evolution and Assembly of GaLaxies and their Environments”, Schaye et al. 2015) zoom simulations of a range of Milky Way-like galaxies that can uniquely reproduce the metallicities of galactic stars, the ISM, and now the circumgalactic medium (CGM) as probed by quasar absorption line surveys. The surprising result is that the average L* galaxy loses more oxygen to the CGM out to hundreds of kpcs from a galaxy than it retains in its stars. These zooms not only follow the nucleosynthetic yields of 11 elements, they follow the non-equilibrium ionization and cooling of 133 ions, which allow direct comparison to observations of the COS-Halos survey of O VI in galactic halos out to 150 kpc (Tumlinson et al. 2011). The result is a new understanding of the galactic nucleosynthetic yield budget in simulations where galaxies are dramatically shaped by supernovae and black hole feedback. We are now closer to reconciling observed stellar, ISM, and now CGM metallicities with the nucleosynthetic production of the stellar component.

Absorption Line Spectrum of the Quasi-stellar Object 3C 191

Nature ◽  
1967 ◽  
Vol 215 (5105) ◽  
pp. 1045-1046 ◽  
Author(s):  
D. F. FALLA
Keyword(s):  
Absorption Line ◽  
Stellar Object ◽  
Line Spectrum
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