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Title: ENHANCED DETECTABILITY OF PRE-REIONIZATION 21 cm STRUCTURE

Abstract

Before the universe was reionized, it was likely that the spin temperature of intergalactic hydrogen was decoupled from the cosmic microwave background (CMB) by UV radiation from the first stars through the Wouthuysen-Field effect. If the intergalactic medium (IGM) had not yet been heated above the CMB temperature by that time, then the gas would appear in absorption relative to the CMB. Large, rare sources of X-rays could inject sufficient heat into the neutral IGM, so that {delta}T{sub b} >0 at comoving distances of tens to hundreds of Mpc, resulting in large 21 cm fluctuations with {delta}T{sub b} {approx_equal} 250 mK on arcminute to degree angular scales, an order of magnitude larger in amplitude than that caused by ionized bubbles during reionization, {delta}T{sub b} {approx_equal} 25 mK. This signal could therefore be easier to detect and probe higher redshifts than that due to patchy reionization. For the case in which the first objects to heat the IGM are QSOs hosting 10{sup 7} M {sub sun} black holes with an abundance exceeding {approx}1 Gpc{sup -3} at z {approx} 15, observations with either the Arecibo Observatory or the Five Hundred Meter Aperture Spherical Telescope could detect and image their fluctuations at greatermore » than 5{sigma} significance in about a month of dedicated survey time. Additionally, existing facilities such as MWA and LOFAR could detect the statistical fluctuations arising from a population of 10{sup 5} M {sub sun} black holes with an abundance of {approx}10{sup 4} Gpc{sup -3} at z {approx_equal} 10-12.« less

Authors:
; ;  [1]
  1. Canadian Institute for Theoretical Astrophysics, University of Toronto, 60 St. George St., Toronto, ON M5S 3H8 (Canada)
Publication Date:
OSTI Identifier:
21452721
Resource Type:
Journal Article
Journal Name:
Astrophysical Journal Letters
Additional Journal Information:
Journal Volume: 723; Journal Issue: 1; Other Information: DOI: 10.1088/2041-8205/723/1/L17; Journal ID: ISSN 2041-8205
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ABUNDANCE; BLACK HOLES; COSMOLOGY; HYDROGEN; RED SHIFT; RELICT RADIATION; STARS; TELESCOPES; ULTRAVIOLET RADIATION; UNIVERSE; ELECTROMAGNETIC RADIATION; ELEMENTS; MICROWAVE RADIATION; NONMETALS; RADIATIONS

Citation Formats

Alvarez, Marcelo A, Pen, Ue-Li, and Chang, Tzu-Ching. ENHANCED DETECTABILITY OF PRE-REIONIZATION 21 cm STRUCTURE. United States: N. p., 2010. Web. doi:10.1088/2041-8205/723/1/L17.
Alvarez, Marcelo A, Pen, Ue-Li, & Chang, Tzu-Ching. ENHANCED DETECTABILITY OF PRE-REIONIZATION 21 cm STRUCTURE. United States. https://doi.org/10.1088/2041-8205/723/1/L17
Alvarez, Marcelo A, Pen, Ue-Li, and Chang, Tzu-Ching. Mon . "ENHANCED DETECTABILITY OF PRE-REIONIZATION 21 cm STRUCTURE". United States. https://doi.org/10.1088/2041-8205/723/1/L17.
@article{osti_21452721,
title = {ENHANCED DETECTABILITY OF PRE-REIONIZATION 21 cm STRUCTURE},
author = {Alvarez, Marcelo A and Pen, Ue-Li and Chang, Tzu-Ching},
abstractNote = {Before the universe was reionized, it was likely that the spin temperature of intergalactic hydrogen was decoupled from the cosmic microwave background (CMB) by UV radiation from the first stars through the Wouthuysen-Field effect. If the intergalactic medium (IGM) had not yet been heated above the CMB temperature by that time, then the gas would appear in absorption relative to the CMB. Large, rare sources of X-rays could inject sufficient heat into the neutral IGM, so that {delta}T{sub b} >0 at comoving distances of tens to hundreds of Mpc, resulting in large 21 cm fluctuations with {delta}T{sub b} {approx_equal} 250 mK on arcminute to degree angular scales, an order of magnitude larger in amplitude than that caused by ionized bubbles during reionization, {delta}T{sub b} {approx_equal} 25 mK. This signal could therefore be easier to detect and probe higher redshifts than that due to patchy reionization. For the case in which the first objects to heat the IGM are QSOs hosting 10{sup 7} M {sub sun} black holes with an abundance exceeding {approx}1 Gpc{sup -3} at z {approx} 15, observations with either the Arecibo Observatory or the Five Hundred Meter Aperture Spherical Telescope could detect and image their fluctuations at greater than 5{sigma} significance in about a month of dedicated survey time. Additionally, existing facilities such as MWA and LOFAR could detect the statistical fluctuations arising from a population of 10{sup 5} M {sub sun} black holes with an abundance of {approx}10{sup 4} Gpc{sup -3} at z {approx_equal} 10-12.},
doi = {10.1088/2041-8205/723/1/L17},
url = {https://www.osti.gov/biblio/21452721}, journal = {Astrophysical Journal Letters},
issn = {2041-8205},
number = 1,
volume = 723,
place = {United States},
year = {2010},
month = {11}
}