TY - JOUR
T1 - The correlation between star formation and 21-cm emission during the reionization epoch
AU - Wyithe, J. Stuart B.
AU - Loeb, Abraham
AU - Schmidt, Brian P.
PY - 2007/9
Y1 - 2007/9
N2 - Reionization is thought to be dominated by low-mass galaxies, while direct observations of resolved galaxies probe only the most massive, rarest objects. The cross-correlation between fluctuations in the surface brightness of the cumulative Lyα emission (which serves as a proxy for the star formation rate) and the redshifted 21-cm signal from neutral hydrogen in the intergalactic medium (IGM) will directly probe the causal link between the production of ionizing photons in galaxies and the reionization of the IGM. We discuss the prospects for detecting this cross-correlation for unresolved galaxies. We find that on angular scales ≲10 arcmin detection will be practical using wide-field near-infrared (near-IR) imaging from space in combination with the forthcoming Mileura Wide-field Array - Low Frequency Demonstrator. When redshifted 21-cm observations of the neutral IGM are combined with space-based near-IR imaging of Lyα emission, the detection on angular scales ≲3 arcmin will be limited by the sensitivity of the 21-cm signal, even when a small-aperture optical telescope (∼2 m) and a moderate field of view (∼10 deg2) are used. On scales ≳3 arcmin, the measurement of cross-correlation will be limited by the accuracy of the foreground sky subtraction.
AB - Reionization is thought to be dominated by low-mass galaxies, while direct observations of resolved galaxies probe only the most massive, rarest objects. The cross-correlation between fluctuations in the surface brightness of the cumulative Lyα emission (which serves as a proxy for the star formation rate) and the redshifted 21-cm signal from neutral hydrogen in the intergalactic medium (IGM) will directly probe the causal link between the production of ionizing photons in galaxies and the reionization of the IGM. We discuss the prospects for detecting this cross-correlation for unresolved galaxies. We find that on angular scales ≲10 arcmin detection will be practical using wide-field near-infrared (near-IR) imaging from space in combination with the forthcoming Mileura Wide-field Array - Low Frequency Demonstrator. When redshifted 21-cm observations of the neutral IGM are combined with space-based near-IR imaging of Lyα emission, the detection on angular scales ≲3 arcmin will be limited by the sensitivity of the 21-cm signal, even when a small-aperture optical telescope (∼2 m) and a moderate field of view (∼10 deg2) are used. On scales ≳3 arcmin, the measurement of cross-correlation will be limited by the accuracy of the foreground sky subtraction.
KW - Cosmology: theory
KW - Diffuse radiation
KW - Galaxies: high-redshift
KW - Intergalactic medium
KW - Large-scale structure of Universe
UR - http://www.scopus.com/inward/record.url?scp=34548619563&partnerID=8YFLogxK
U2 - 10.1111/j.1365-2966.2007.12149.x
DO - 10.1111/j.1365-2966.2007.12149.x
M3 - Article
SN - 0035-8711
VL - 380
SP - 1087
EP - 1097
JO - Monthly Notices of the Royal Astronomical Society
JF - Monthly Notices of the Royal Astronomical Society
IS - 3
ER -