Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries

We investigate the influence of high-mass X-ray binaries (HMXBs) on their high-redshift environments. Using a one-dimensional radiative transfer code, we predict the ionization and temperature profiles surrounding a coeval stellar population, composed of main-sequence stars and HMXBs, at various tim...

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Main Authors: Knevitt, G., Wynn, G.A., Power, C., Bolton, James S.
Format: Article
Published: Oxford University Press 2014
Subjects:
Online Access:https://eprints.nottingham.ac.uk/42505/
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author Knevitt, G.
Wynn, G.A.
Power, C.
Bolton, James S.
author_facet Knevitt, G.
Wynn, G.A.
Power, C.
Bolton, James S.
author_sort Knevitt, G.
building Nottingham Research Data Repository
collection Online Access
description We investigate the influence of high-mass X-ray binaries (HMXBs) on their high-redshift environments. Using a one-dimensional radiative transfer code, we predict the ionization and temperature profiles surrounding a coeval stellar population, composed of main-sequence stars and HMXBs, at various times after its formation. We consider both uniform density surroundings, and a cluster embedded in a 108 M⊙ Navarro–Frenk–White (NFW) halo. HMXBs in a constant density environment produce negligible enhanced ionization because of their high-energy spectral energy distributions and short lifetimes. In this case, HMXBs only marginally contribute to the local heating rate. For NFW profiles, radiation from main-sequence stars cannot prevent the initially ionized volume from recombining since it is unable to penetrate the high-density galactic core. However, HMXB photons stall recombinations behind the front, keeping it partially ionized for longer. The increased electron density in these partially ionized regions promotes further cooling, resulting in lower intergalactic medium (IGM) temperatures. In the context of this starburst model, we have shown that HMXBs do not make a major contribution to reionization or IGM heating. However, X-ray escape fractions are high in both density profile cases. Continuous star formation may result in the build up of X-rays over time, reducing the ionization time-scale and potentially leading to low level ionization of the distant IGM.
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spelling nottingham-425052020-05-04T16:55:56Z https://eprints.nottingham.ac.uk/42505/ Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries Knevitt, G. Wynn, G.A. Power, C. Bolton, James S. We investigate the influence of high-mass X-ray binaries (HMXBs) on their high-redshift environments. Using a one-dimensional radiative transfer code, we predict the ionization and temperature profiles surrounding a coeval stellar population, composed of main-sequence stars and HMXBs, at various times after its formation. We consider both uniform density surroundings, and a cluster embedded in a 108 M⊙ Navarro–Frenk–White (NFW) halo. HMXBs in a constant density environment produce negligible enhanced ionization because of their high-energy spectral energy distributions and short lifetimes. In this case, HMXBs only marginally contribute to the local heating rate. For NFW profiles, radiation from main-sequence stars cannot prevent the initially ionized volume from recombining since it is unable to penetrate the high-density galactic core. However, HMXB photons stall recombinations behind the front, keeping it partially ionized for longer. The increased electron density in these partially ionized regions promotes further cooling, resulting in lower intergalactic medium (IGM) temperatures. In the context of this starburst model, we have shown that HMXBs do not make a major contribution to reionization or IGM heating. However, X-ray escape fractions are high in both density profile cases. Continuous star formation may result in the build up of X-rays over time, reducing the ionization time-scale and potentially leading to low level ionization of the distant IGM. Oxford University Press 2014-10-14 Article PeerReviewed Knevitt, G., Wynn, G.A., Power, C. and Bolton, James S. (2014) Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries. Monthly Notices of the Royal Astronomical Society, 445 (2). pp. 2034-2048. ISSN 1365-2966 Galaxies: formation Cosmology: theory X-rays: binaries https://academic.oup.com/mnras/article-lookup/doi/10.1093/mnras/stu1803 doi:10.1093/mnras/stu1803 doi:10.1093/mnras/stu1803
spellingShingle Galaxies: formation
Cosmology: theory
X-rays: binaries
Knevitt, G.
Wynn, G.A.
Power, C.
Bolton, James S.
Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries
title Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries
title_full Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries
title_fullStr Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries
title_full_unstemmed Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries
title_short Heating and ionization of the primordial intergalactic medium by high mass x-ray binaries
title_sort heating and ionization of the primordial intergalactic medium by high mass x-ray binaries
topic Galaxies: formation
Cosmology: theory
X-rays: binaries
url https://eprints.nottingham.ac.uk/42505/
https://eprints.nottingham.ac.uk/42505/
https://eprints.nottingham.ac.uk/42505/