The 21-cm radiation from minihaloes as a probe of small primordial non-Gaussianity

Sirichai Chongchitnan, Joseph Silk

Research output: Contribution to journalArticle

14 Citations (Scopus)
14 Downloads (Pure)

Abstract

We present a new probe of primordial non-Gaussianity via the 21-cm radiation from minihaloes at high redshifts. We calculate the fluctuations in the brightness temperature (measured against the cosmic microwave background) of the 21-cm background from minihaloes containing H i at redshift ∼6–20, and find a significant enhancement due to small non-Gaussianity with amplitude fNL ≲ 1. This enhancement can be attributed to the non-linear bias which is strongly increased in the presence of non-Gaussianity. We show that our results are robust against changes in the assumed mass function and some physical aspects of minihalo formation, but are nevertheless sensitive to the presence of strong radiation sources within or around the minihaloes. Our findings are relevant for constraining and searching for small primordial non-Gaussianity with upcoming radio telescopes such as Low-Frequency Array (LOFAR) and Square Kilometre Array (SKA).
Original languageEnglish
JournalMonthly Notices of the Royal Astronomical Society: Letters
Volume61
DOIs
Publication statusPublished - Oct 2012
Externally publishedYes

Fingerprint

probe
augmentation
probes
radio telescopes
brightness temperature
radiation
radiation sources
radio
low frequencies
microwaves
microwave

Cite this

@article{39a08e30774e4409b6032488746939a8,
title = "The 21-cm radiation from minihaloes as a probe of small primordial non-Gaussianity",
abstract = "We present a new probe of primordial non-Gaussianity via the 21-cm radiation from minihaloes at high redshifts. We calculate the fluctuations in the brightness temperature (measured against the cosmic microwave background) of the 21-cm background from minihaloes containing H i at redshift ∼6–20, and find a significant enhancement due to small non-Gaussianity with amplitude fNL ≲ 1. This enhancement can be attributed to the non-linear bias which is strongly increased in the presence of non-Gaussianity. We show that our results are robust against changes in the assumed mass function and some physical aspects of minihalo formation, but are nevertheless sensitive to the presence of strong radiation sources within or around the minihaloes. Our findings are relevant for constraining and searching for small primordial non-Gaussianity with upcoming radio telescopes such as Low-Frequency Array (LOFAR) and Square Kilometre Array (SKA).",
author = "Sirichai Chongchitnan and Joseph Silk",
year = "2012",
month = "10",
doi = "10.1111/j.1745-3933.2012.01315.x",
language = "English",
volume = "61",
journal = "Monthly Notices of the Royal Astronomical Society: Letters",
issn = "1745-3925",
publisher = "Oxford University Press",

}

The 21-cm radiation from minihaloes as a probe of small primordial non-Gaussianity. / Chongchitnan, Sirichai; Silk, Joseph.

In: Monthly Notices of the Royal Astronomical Society: Letters, Vol. 61, 10.2012.

Research output: Contribution to journalArticle

TY - JOUR

T1 - The 21-cm radiation from minihaloes as a probe of small primordial non-Gaussianity

AU - Chongchitnan, Sirichai

AU - Silk, Joseph

PY - 2012/10

Y1 - 2012/10

N2 - We present a new probe of primordial non-Gaussianity via the 21-cm radiation from minihaloes at high redshifts. We calculate the fluctuations in the brightness temperature (measured against the cosmic microwave background) of the 21-cm background from minihaloes containing H i at redshift ∼6–20, and find a significant enhancement due to small non-Gaussianity with amplitude fNL ≲ 1. This enhancement can be attributed to the non-linear bias which is strongly increased in the presence of non-Gaussianity. We show that our results are robust against changes in the assumed mass function and some physical aspects of minihalo formation, but are nevertheless sensitive to the presence of strong radiation sources within or around the minihaloes. Our findings are relevant for constraining and searching for small primordial non-Gaussianity with upcoming radio telescopes such as Low-Frequency Array (LOFAR) and Square Kilometre Array (SKA).

AB - We present a new probe of primordial non-Gaussianity via the 21-cm radiation from minihaloes at high redshifts. We calculate the fluctuations in the brightness temperature (measured against the cosmic microwave background) of the 21-cm background from minihaloes containing H i at redshift ∼6–20, and find a significant enhancement due to small non-Gaussianity with amplitude fNL ≲ 1. This enhancement can be attributed to the non-linear bias which is strongly increased in the presence of non-Gaussianity. We show that our results are robust against changes in the assumed mass function and some physical aspects of minihalo formation, but are nevertheless sensitive to the presence of strong radiation sources within or around the minihaloes. Our findings are relevant for constraining and searching for small primordial non-Gaussianity with upcoming radio telescopes such as Low-Frequency Array (LOFAR) and Square Kilometre Array (SKA).

U2 - 10.1111/j.1745-3933.2012.01315.x

DO - 10.1111/j.1745-3933.2012.01315.x

M3 - Article

VL - 61

JO - Monthly Notices of the Royal Astronomical Society: Letters

JF - Monthly Notices of the Royal Astronomical Society: Letters

SN - 1745-3925

ER -