Physical properties of the intergalactic medium and the Lyman-alpha absorbing clouds

1983 ◽  
Vol 268 ◽  
pp. L63 ◽  
Author(s):  
J. P. Ostriker ◽  
S. Ikeuchi
Keyword(s):  
Physical Properties ◽  
Intergalactic Medium ◽  
Lyman Alpha

scholarly journals QSO Absorption Lines and Cosmology

1987 ◽  
Vol 124 ◽  
pp. 777-792 ◽  
Author(s):  
Wallace L. W. Sargent
Keyword(s):  
Physical Properties ◽  
Recent Work ◽  
Intergalactic Medium ◽  
Cosmological Evolution ◽  
Absorption Lines ◽  
Lyman Alpha ◽  
Different Types ◽  
Potential Applications ◽  
The Universe

The properties of the different types of QSO absorption systems are briefly summarized. An overview is given of the potential applications of absorption lines in cosmology. Recent work on the cosmological evolution of the different types of absorbers is discussed. The physical properties of the intergalactic medium are discussed in the light of recent work on the “Lyman alpha clouds”. The uses of the lines for studies of the evolution of clustering in the Universe are described. Recent puzzling results on common absorption in pairs of QSOs, particularly Q1037–2704 and Q1038–2712, are summarized.

scholarly journals Simulations of the Intergalactic Medium

2005 ◽  
Vol 216 ◽  
pp. 251-265
Author(s):  
Romeel Davé
Keyword(s):  
Absorption Line ◽  
Galaxy Formation ◽  
Intergalactic Medium ◽  
Ultraviolet Absorption ◽  
Multiple Populations ◽  
Hydrodynamic Simulations ◽  
Lyman Alpha ◽  
Lyman Alpha Forest ◽  
Working Together

I present an epochal review of baryons in the intergalactic medium (IGM), from the reionization epoch until today. Recent observations indicate a protracted period of reionization, suggesting multiple populations of reionizers; detection of these z ≳ 6 sources is a key goal that is now coming within reach. The optical Lyman alpha forest (2 ≲ z ≲ 4) is well-described by the Fluctuating Gunn-Peterson Approximation, but recent observations of galaxies and metal lines associated with Lyα absorbers remain puzzling. IGM studies at z ≲ 1.5 are progressing rapidly thanks to ultraviolet absorption line studies of both Lyα absorbers and the warm-hot intergalactic medium. Cosmological hydrodynamic simulations have played an integral part in these advances, and have helped to revolutionize our understanding of the IGM at various epochs. Working together, observations and theory continue to expand our knowledge of the IGM as the earliest stage of galaxy formation and the dominant reservoir of baryons at all redshifts.

scholarly journals HSTEMISSION LINE GALAXIES ATz∼ 2: COMPARING PHYSICAL PROPERTIES OF LYMAN ALPHA AND OPTICAL EMISSION LINE SELECTED GALAXIES

2016 ◽  
Vol 817 (1) ◽  
pp. 79 ◽  
Author(s):  
Alex Hagen ◽  
Gregory R. Zeimann ◽  
Christoph Behrens ◽  
Robin Ciardullo ◽  
Henry S. Grasshorn Gebhardt ◽  
...  
Keyword(s):  
Physical Properties ◽  
Emission Line ◽  
Optical Emission ◽  
Lyman Alpha

scholarly journals Physical properties and evolutionary state of the Lyman alpha emitting starburst galaxy IRAS 08339+6517

2014 ◽  
Vol 566 ◽  
pp. A38 ◽  
Author(s):  
H. Otí-Floranes ◽  
J. M. Mas-Hesse ◽  
E. Jiménez-Bailón ◽  
D. Schaerer ◽  
M. Hayes ◽  
...  
Keyword(s):  
Physical Properties ◽  
Starburst Galaxy ◽  
Lyman Alpha ◽  
Evolutionary State

scholarly journals Galaxies at z ~ 6: physical properties at the edge of the cosmic reionization

2015 ◽  
Vol 11 (S319) ◽  
pp. 7-9 ◽  
Author(s):  
Stephane de Barros ◽  
Eros Vanzella ◽  
Laura Pentericci ◽  
Adriano Fontana ◽  
Andrea Grazian ◽  
...  
Keyword(s):  
Physical Properties ◽  
Massive Stars ◽  
Neutral Hydrogen ◽  
Emission Lines ◽  
Lyman Alpha ◽  
Alpha Emitters ◽  
Hydrogen Density ◽  
Lyman Alpha Emitters ◽  
Dust Attenuation ◽  
Lower Redshift

AbstractAn important effort has been recently made to detect spectroscopically galaxies at z ~ 6 and higher where the cosmic reionization is thought to occur. The drop of the fraction of Lyman Alpha Emitters (LAEs) at z>6 is currently interpreted as an effect of the increasing neutral hydrogen density.We present preliminary results from the latest VLT/FORS2 programs, combined with ESO archival data, to perform a large census of z ~ 6 galaxies. We derive their physical properties as stellar mass and dust attenuation with an SED fitting tool including nebular emission which is of primeval importance because IRAC channels are strongly contaminated by emission lines at those redshifts. We take a special care to derive with precision the redshift of non LAEs to perform a comparison of their properties with the LAE population and derive as accurately as possible the fraction of LAEs. In particular, we compare the UV beta slope with the Lyα equivalent width which are known to correlate at lower redshift.We also report the detection of few peculiar z ~ 6 galaxies with extremely blue UV β slope (~−3), which can be a signature of unusual stellar populations (e.g., very hot and massive stars).

scholarly journals Lyα emitters in a cosmological volume II: the impact of the intergalactic medium

2019 ◽  
Author(s):  
Siddhartha Gurung-López ◽  
Álvaro A Orsi ◽  
Silvia Bonoli ◽  
Nelson Padilla ◽  
Cedric G Lacey ◽  
...  
Keyword(s):  
Radiative Transfer ◽  
Large Scale ◽  
Intergalactic Medium ◽  
High Redshift ◽  
Acoustic Oscillation ◽  
Galaxy Surveys ◽  
Lyman Alpha ◽  
Potential Difficulty ◽  
Scale Properties ◽  
The Impact

Abstract In the near future galaxy surveys will target Lyman alpha emitting galaxies (LAEs) to unveil the nature of dark energy. It has been suggested that the observability of LAEs is coupled to the large scale properties of the intergalactic medium. Such coupling could introduce distortions into the observed clustering of LAEs, adding a new potential difficulty to the interpretation of upcoming surveys. We present a model of LAEs that incorporates $\rm {Ly}\alpha$ radiative transfer processes in the interstellar and intergalactic medium. The model is implemented in the GALFORM semi-analytic model of galaxy of formation and evolution. We find that the radiative transfer inside galaxies produces selection effects over galaxy properties. In particular, observed LAEs tend to have low metallicities and intermediate star formation rates. At low redshift we find no evidence of a correlation between the spatial distribution of LAEs and the intergalactic medium properties. However, at high redshift the LAEs are linked to the line of sight velocity and density gradient of the intergalactic medium. The strength of the coupling depends on the outflow properties of the galaxies and redshift. This effect modifies the clustering of LAEs on large scales, adding non linear features. In particular, our model predicts modifications to the shape and position of the baryon acoustic oscillation peak. This work highlights the importance of including radiative transfer physics in the cosmological analysis of LAEs.

scholarly journals THE MAGELLANIC BRIDGE AS A DAMPED LYMAN ALPHA SYSTEM: PHYSICAL PROPERTIES OF COLD GAS TOWARD PKS 0312-770

2009 ◽  
Vol 695 (2) ◽  
pp. 1382-1398 ◽  
Author(s):  
Toru Misawa ◽  
Jane C. Charlton ◽  
Henry A. Kobulnicky ◽  
Bart P. Wakker ◽  
Joss Bland-Hawthorn
Keyword(s):  
Physical Properties ◽  
Lyman Alpha ◽  
Cold Gas
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