Lyman-alpha absorption spectrum of the primordial intergalactic medium

1993 ◽  
Vol 405 ◽  
pp. 479 ◽  
Author(s):  
Hongguang Bi
Keyword(s):  
Absorption Spectrum ◽  
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.

Absorption spectrum of the Z = 3.78 QSO 2000 - 330. I - The Lyman-alpha forest region at 1.5 A resolution

1986 ◽  
Vol 305 ◽  
pp. 496 ◽  
Author(s):  
R. W. Hunstead ◽  
H. S. Murdoch ◽  
B. A. Peterson ◽  
J. C. Blades ◽  
D. L. Jauncey ◽  
...  
Keyword(s):  
Absorption Spectrum ◽  
Lyman Alpha ◽  
Forest Region ◽  
Lyman Alpha Forest

The ultraviolet absorption spectrum of the quasar PKS 0405-12 and the local density of Lyman-alpha absorption systems

1993 ◽  
Vol 405 ◽  
pp. 491 ◽  
Author(s):  
John N. Bahcall ◽  
Buell T. Jannuzi ◽  
Donald P. Schneider ◽  
George F. Hartig
Keyword(s):  
Absorption Spectrum ◽  
Local Density ◽  
Ultraviolet Absorption ◽  
Ultraviolet Absorption Spectrum ◽  
Lyman Alpha

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 Non-parametric 3D map of the intergalactic medium using the Lyman-alpha forest

2014 ◽  
Vol 440 (3) ◽  
pp. 2599-2609 ◽  
Author(s):  
Jessi Cisewski ◽  
Rupert A. C. Croft ◽  
Peter E. Freeman ◽  
Christopher R. Genovese ◽  
Nishikanta Khandai ◽  
...  
Keyword(s):  
Intergalactic Medium ◽  
Lyman Alpha ◽  
Lyman Alpha Forest ◽  
Non Parametric

scholarly journals Lyman-alpha spectroscopy of extreme [O iii] emitting galaxies at z ≃ 2-3: implications for Lyα visibility and LyC leakage at z > 6

2021 ◽  
Vol 503 (3) ◽  
pp. 4105-4117
Author(s):  
Mengtao Tang ◽  
Daniel P Stark ◽  
Jacopo Chevallard ◽  
Stéphane Charlot ◽  
Ryan Endsley ◽  
...  
Keyword(s):  
General Population ◽  
Ionizing Radiation ◽  
Equivalent Width ◽  
Intergalactic Medium ◽  
Line Emission ◽  
Alpha Spectroscopy ◽  
Detection Rates ◽  
Lyman Alpha ◽  
Enhanced Transmission ◽  
Extreme Line

ABSTRACT Spectroscopic observations of massive z > 7 galaxies selected to have extremely large [O iii] + H β equivalent width (EW ∼1500 Å) have recently revealed large Ly α detection rates, in contrast to the weak emission seen in the general population. Why these systems are uniquely visible in Ly α at redshifts where the intergalactic medium (IGM) is likely significantly neutral is not clear. With the goal of better understanding these results, we have begun a campaign with MMT and Magellan to measure Ly α in galaxies with similar [O iii] + H β EWs at z ≃ 2–3. At these redshifts, the IGM is highly ionized, allowing us to clearly disentangle how the Ly α properties depend on the [O iii] + H β EW. Here, we present Ly α EWs of 49 galaxies at z = 2.2–3.7 with intense [O iii] + H β line emission (EW = 300–3000 Å). Our results demonstrate that strong Ly α emission (EW >20 Å) becomes more common in galaxies with larger [O iii] + H β EW, reflecting a combination of increasingly efficient ionizing photon production and enhanced transmission of Ly α. Among the galaxies with the most extreme [O iii] + H β emission (EW ∼1500 Å), we find that strong Ly α emission is not ubiquitous, with only 50 per cent of our population showing Ly α EW >20 Å. Our data suggest that the range of Ly α strengths is related to the observed ellipticity, with those systems that appear edge-on or elongated having weaker Ly α emission. We use these results to interpret the anomalous Ly α properties seen in z > 7 galaxies with extreme [O iii] + H β emission and discuss implications for the escape of ionizing radiation from these extreme line emitting galaxies.

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