Searching for the Sources Responsible for Cosmic Reionization: Probing 7 < z < 10 and Beyond

Abstract

(Abridged) We review recent observations that suggest the star formation rate density is declining over 3$<z<$7 and illustrate the challenges that this poses in explaining the assembled stellar mass in z$\sim$6 galaxies deduced from Spitzer data. A plausible conclusion is a vigorous period of earlier star formation. Prior to JWST and TMT, strong lensing offers a unique probe of the extent of this earlier activity. We discuss the first results of a blind spectroscopic survey of lensing clusters for 8.5$<z<$10 Ly$\alpha$ emitters using NIRSPEC which is achieving a limiting star formation rate of 0.1 $M_{\odot }$ yr${}^{-1}$. A companion HST/IRAC survey is targeting lensed $z$ and $J$-band dropouts and probes a $\simeq$1 arcmin${}^2$ region 1 magnitude deeper than the UDF/NICMOS observations. Both surveys will constrain the contribution of early, low luminosity, sources to cosmic reionization.

12 pages, 6 figures, to appear in "First Light & Reionization", eds. E. Barton & A. Cooray, New Astronomy Reviews, in press

References in corpus (5)

• Galaxies at z~7-8: z-dropouts in the Hubble Ultra Deep Field
• Evidence for a Massive Post-Starburst Galaxy at z ~ 6.5
• Rest-frame Ultraviolet-to-Optical Properties of Galaxies at z ~ 6 and 5 in the Hubble Ultra Deep Field: from Hubble to Spitzer
• Spitzer and Hubble Constraints on the Physical Properties of the z~7 Galaxy Strongly Lensed by Abell 2218
• Constraints on z~10 Galaxies from the Deepest HST NICMOS Fields

Cited by in corpus (12)

• Cosmology at Low Frequencies: The 21 cm Transition and the High-Redshift Universe
• A galaxy at a redshift z = 6.96
• A New Measurement of the Stellar Mass Density at z~5: Implications for the Sources of Cosmic Reionization
• The Physical Properties and Detectability of Reionization-Epoch Galaxies
• Unveiling the oldest and most massive galaxies at very high redshift
• The imprint of cosmic reionisation on the luminosity function of galaxies
• An Empirically-Calibrated Model For Interpreting the Evolution of Galaxies During the Reionization Era
• Dwarf Galaxy Formation Was Suppressed By Cosmic Reionization
• A statistical study of multiply-imaged systems in the lensing cluster Abell 68
• Estimating Luminosity Function Constraints from High-Redshift Galaxy Surveys
• Detecting Reionization in the Star Formation Histories of High-Redshift Galaxies
• Observations of the High Redshift Universe