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Title: The power spectrum of the Lyman-α Forest at z < 0.5

Abstract

We present new measurements of the flux power-spectrum P(k) of the z < 0.5 H i Lyman-α Forest spanning scales k ~ 0.001-0.1 s, km-1. These results were derived from 65 far-ultraviolet quasar spectra (resolution R ~ 18, 000) observed with the Cosmic Origin Spectrograph (COS) on board the Hubble Space Telescope. The analysis required careful masking of all contaminating, coincident absorption from H I and metal-line transitions of the Galactic interstellar medium and intervening absorbers as well as proper treatment of the complex COS line-spread function. From the P(k) measurements, we estimate the H I photoionization rate (ΓH,I) in the z < 0.5 intergalactic medium. Our results confirm most of the previous ΓHI estimates. We conclude that previous concerns of a photon underproduction crisis are now resolved by demonstrating that the measured ΓHI can be accounted for by ultraviolet emission from quasars alone. In a companion paper, we will present constraints on the thermal state of the z < 0.5 intergalactic medium from the P(k) measurements presented here.

Authors:
ORCiD logo [1];  [2];  [3];  [4];  [5];  [6];  [7]; ORCiD logo [8];  [9]
  1. Physics Department, Broida Hall, University of California Santa Barbara, Santa Barbara, CA 93106-9530, USA
  2. Physics Department, Broida Hall, University of California Santa Barbara, Santa Barbara, CA 93106-9530, USA, Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany, International Max Planck Research School for Astronomy & Cosmic Physics at the University of Heidelberg, D-69126 Heidelberg, Germany
  3. Physics Department, Broida Hall, University of California Santa Barbara, Santa Barbara, CA 93106-9530, USA, Max-Planck-Institut für Astronomie, Königstuhl 17, D-69117 Heidelberg, Germany
  4. Royal Observatories, Blackford Hill, Edinburgh EH9 3HJ, UK
  5. Lawrence Berkeley National Laboratory, 1 Cyclotron Road, Berkeley, CA 94720, USA
  6. Astronomy and Astrophysics, UC Santa Cruz, 1156 High St., Santa Cruz, CA 95064, USA
  7. Department of Astronomy, University of Massachusetts – Amherst, 710 North Pleasant Street, Amherst, MA 01003-9305, USA
  8. UCO / Lick Observatory, University of California, Santa Cruz, CA 95064, USA
  9. Physics Department, Broida Hall, University of California Santa Barbara, Santa Barbara, CA 93106-9530, USA, Department of Physics and Astronomy, University of California, Irvine, CA 92697, USA
Publication Date:
Research Org.:
Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States)
Sponsoring Org.:
USDOE; USDOE Office of Science (SC), Advanced Scientific Computing Research (ASCR) (SC-21), Scientific Discovery through Advanced Computing (SciDAC) (SC21.1 )
OSTI Identifier:
1526072
Alternate Identifier(s):
OSTI ID: 1576504
Grant/Contract Number:  
AC02-05CH11231
Resource Type:
Published Article
Journal Name:
Monthly Notices of the Royal Astronomical Society
Additional Journal Information:
Journal Name: Monthly Notices of the Royal Astronomical Society Journal Volume: 486 Journal Issue: 1; Journal ID: ISSN 0035-8711
Publisher:
Oxford University Press
Country of Publication:
United Kingdom
Language:
English
Subject:
75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY

Citation Formats

Khaire, Vikram, Walther, Michael, Hennawi, Joseph F., Oñorbe, Jose, Lukić, Zarija, Prochaska, J. Xavier, Tripp, Todd M., Burchett, Joseph N., and Rodriguez, Christian. The power spectrum of the Lyman-α Forest at z < 0.5. United Kingdom: N. p., 2019. Web. doi:10.1093/mnras/stz344.
Khaire, Vikram, Walther, Michael, Hennawi, Joseph F., Oñorbe, Jose, Lukić, Zarija, Prochaska, J. Xavier, Tripp, Todd M., Burchett, Joseph N., & Rodriguez, Christian. The power spectrum of the Lyman-α Forest at z < 0.5. United Kingdom. doi:10.1093/mnras/stz344.
Khaire, Vikram, Walther, Michael, Hennawi, Joseph F., Oñorbe, Jose, Lukić, Zarija, Prochaska, J. Xavier, Tripp, Todd M., Burchett, Joseph N., and Rodriguez, Christian. Sun . "The power spectrum of the Lyman-α Forest at z < 0.5". United Kingdom. doi:10.1093/mnras/stz344.
@article{osti_1526072,
title = {The power spectrum of the Lyman-α Forest at z < 0.5},
author = {Khaire, Vikram and Walther, Michael and Hennawi, Joseph F. and Oñorbe, Jose and Lukić, Zarija and Prochaska, J. Xavier and Tripp, Todd M. and Burchett, Joseph N. and Rodriguez, Christian},
abstractNote = {We present new measurements of the flux power-spectrum P(k) of the z < 0.5 H i Lyman-α Forest spanning scales k ~ 0.001-0.1 s, km-1. These results were derived from 65 far-ultraviolet quasar spectra (resolution R ~ 18, 000) observed with the Cosmic Origin Spectrograph (COS) on board the Hubble Space Telescope. The analysis required careful masking of all contaminating, coincident absorption from H I and metal-line transitions of the Galactic interstellar medium and intervening absorbers as well as proper treatment of the complex COS line-spread function. From the P(k) measurements, we estimate the H I photoionization rate (ΓH,I) in the z < 0.5 intergalactic medium. Our results confirm most of the previous ΓHI estimates. We conclude that previous concerns of a photon underproduction crisis are now resolved by demonstrating that the measured ΓHI can be accounted for by ultraviolet emission from quasars alone. In a companion paper, we will present constraints on the thermal state of the z < 0.5 intergalactic medium from the P(k) measurements presented here.},
doi = {10.1093/mnras/stz344},
journal = {Monthly Notices of the Royal Astronomical Society},
number = 1,
volume = 486,
place = {United Kingdom},
year = {2019},
month = {2}
}

Journal Article:
Free Publicly Available Full Text
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DOI: 10.1093/mnras/stz344

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