Signatures of X-rays in the early Universe
With their long mean free paths and efficient heating of the intergalactic medium (IGM), X-rays could have a dramatic impact on the thermal and ionization history of the Universe. Here we run several semi-numerical simulations of the dark ages and the epoch of reionization (EoR), including both X-ra...
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ftscnormpisairis:oai:ricerca.sns.it:11384/24628 2024-04-14T08:19:49+00:00 Signatures of X-rays in the early Universe MESINGER, ANDREI ALBERT FERRARA, ANDREA Spiegel DS Mesinger, ANDREI ALBERT Ferrara, Andrea Spiegel, Ds 2013 http://hdl.handle.net/11384/24628 https://doi.org/10.1093/mnras/stt198 eng eng info:eu-repo/semantics/altIdentifier/wos/WOS:000318343600072 volume:431 issue:1 firstpage:621 lastpage:637 numberofpages:17 journal:MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY http://hdl.handle.net/11384/24628 doi:10.1093/mnras/stt198 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84876789774 Cosmology: Theory Dark ages reionization first star Early Universe Intergalactic medium X-rays: Galaxie info:eu-repo/semantics/article 2013 ftscnormpisairis https://doi.org/10.1093/mnras/stt198 2024-03-21T17:58:17Z With their long mean free paths and efficient heating of the intergalactic medium (IGM), X-rays could have a dramatic impact on the thermal and ionization history of the Universe. Here we run several semi-numerical simulations of the dark ages and the epoch of reionization (EoR), including both X-rays and ultraviolet radiation fields, attempting to provide an intuitive framework for interpreting upcoming observations. We explore the impact of X-rays on various signals. (i) Reionization history: Including X-rays results in an earlier, slightly more extended EoR. However, efficient thermal feedback from X-ray heating could yield an extended epoch in which the Universe was ≈10 per cent ionized. (ii) Reionization morphology: A sizeable (~10 per cent) contribution of X-rays to reionization results in a more uniform morphology, though the impact is modest when compared at the same global neutral fraction, xHI. Specifically, X-rays produce a dearth of fully neutral regions and a suppression of small-scale (k > 0.1Mpc-1) ionization power by a factor of <2. However, these changes in morphology cannot be countered by increasing the bias of the ionizing sources, making them a robust indicator of an X-ray contribution to the EoR. (iii) The kinetic Sunyaev-Zel'dovich (kSZ) effect: At a fixed reionization history, X-rays decrease the kSZ power at l = 3000 by ≈0.5 μK2. Our extreme model in which X-rays entirely drive reionization is the only one which is marginally consistent with the recent upper limits on this signal from the South Pole Telescope, assuming no thermal Sunyaev-Zel'dovich (tSZ)-dusty galaxy cross-correlation. Since this extreme model is unlikely, we conclude that there should be a sizeable tSZ-dusty galaxy cross-correlation. (iv) The redshifted 21 cm signal: The impact of X-rays on the 21 cm power spectrum during the advanced stages of reionization (xHI < 0.7) is modest, except in extreme, X-ray-dominated models. The largest impact of X-rays is to govern the timing and duration of IGM heating. In fact, ... Article in Journal/Newspaper South pole Scuola Normale Superiore: CINECA IRIS South Pole Monthly Notices of the Royal Astronomical Society 431 1 621 637 |
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Scuola Normale Superiore: CINECA IRIS |
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English |
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Cosmology: Theory Dark ages reionization first star Early Universe Intergalactic medium X-rays: Galaxie |
spellingShingle |
Cosmology: Theory Dark ages reionization first star Early Universe Intergalactic medium X-rays: Galaxie MESINGER, ANDREI ALBERT FERRARA, ANDREA Spiegel DS Signatures of X-rays in the early Universe |
topic_facet |
Cosmology: Theory Dark ages reionization first star Early Universe Intergalactic medium X-rays: Galaxie |
description |
With their long mean free paths and efficient heating of the intergalactic medium (IGM), X-rays could have a dramatic impact on the thermal and ionization history of the Universe. Here we run several semi-numerical simulations of the dark ages and the epoch of reionization (EoR), including both X-rays and ultraviolet radiation fields, attempting to provide an intuitive framework for interpreting upcoming observations. We explore the impact of X-rays on various signals. (i) Reionization history: Including X-rays results in an earlier, slightly more extended EoR. However, efficient thermal feedback from X-ray heating could yield an extended epoch in which the Universe was ≈10 per cent ionized. (ii) Reionization morphology: A sizeable (~10 per cent) contribution of X-rays to reionization results in a more uniform morphology, though the impact is modest when compared at the same global neutral fraction, xHI. Specifically, X-rays produce a dearth of fully neutral regions and a suppression of small-scale (k > 0.1Mpc-1) ionization power by a factor of <2. However, these changes in morphology cannot be countered by increasing the bias of the ionizing sources, making them a robust indicator of an X-ray contribution to the EoR. (iii) The kinetic Sunyaev-Zel'dovich (kSZ) effect: At a fixed reionization history, X-rays decrease the kSZ power at l = 3000 by ≈0.5 μK2. Our extreme model in which X-rays entirely drive reionization is the only one which is marginally consistent with the recent upper limits on this signal from the South Pole Telescope, assuming no thermal Sunyaev-Zel'dovich (tSZ)-dusty galaxy cross-correlation. Since this extreme model is unlikely, we conclude that there should be a sizeable tSZ-dusty galaxy cross-correlation. (iv) The redshifted 21 cm signal: The impact of X-rays on the 21 cm power spectrum during the advanced stages of reionization (xHI < 0.7) is modest, except in extreme, X-ray-dominated models. The largest impact of X-rays is to govern the timing and duration of IGM heating. In fact, ... |
author2 |
Mesinger, ANDREI ALBERT Ferrara, Andrea Spiegel, Ds |
format |
Article in Journal/Newspaper |
author |
MESINGER, ANDREI ALBERT FERRARA, ANDREA Spiegel DS |
author_facet |
MESINGER, ANDREI ALBERT FERRARA, ANDREA Spiegel DS |
author_sort |
MESINGER, ANDREI ALBERT |
title |
Signatures of X-rays in the early Universe |
title_short |
Signatures of X-rays in the early Universe |
title_full |
Signatures of X-rays in the early Universe |
title_fullStr |
Signatures of X-rays in the early Universe |
title_full_unstemmed |
Signatures of X-rays in the early Universe |
title_sort |
signatures of x-rays in the early universe |
publishDate |
2013 |
url |
http://hdl.handle.net/11384/24628 https://doi.org/10.1093/mnras/stt198 |
geographic |
South Pole |
geographic_facet |
South Pole |
genre |
South pole |
genre_facet |
South pole |
op_relation |
info:eu-repo/semantics/altIdentifier/wos/WOS:000318343600072 volume:431 issue:1 firstpage:621 lastpage:637 numberofpages:17 journal:MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY http://hdl.handle.net/11384/24628 doi:10.1093/mnras/stt198 info:eu-repo/semantics/altIdentifier/scopus/2-s2.0-84876789774 |
op_doi |
https://doi.org/10.1093/mnras/stt198 |
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