Welcome to the new version of CaltechAUTHORS. Login is currently restricted to library staff. If you notice any issues, please email coda@library.caltech.edu
Published June 1, 2009 | Published
Journal Article Open

Expanding the Search for Galaxies at z ~ 7-10 with New NICMOS Parallel Fields


We have carried out a search for galaxies at z ~ 7-10 in ~14.4 arcmin^2 of new NICMOS parallel imaging taken in the Great Observatories Origins Deep Survey (5.9 arcmin^2), the Cosmic Origins Survey (7.2 arcmin^2), and SSA22 (1.3 arcmin^2). These images reach 5σ sensitivities of J_(110) = 26.0-27.5 (AB), and combined they increase the amount of deep near-infrared data by more than 60% in fields where the investment in deep optical data has already been made. We find no z > 7 candidates in our survey area, consistent with the Bouwens et al. measurements at z ~ 7 and 9 (over 23 arcmin^2), which predict 0.7 galaxies at z ~ 7 and <0.03 galaxies at z ~ 9. We estimate that 10%-20% of z > 7 galaxies are missed by this survey, due to incompleteness from foreground contamination by faint sources. For the case of luminosity evolution, assuming a Schecter parameterization with a typical Φ_* = 10^(–3) Mpc^(–3), we find M^*> – 20.0 for z ~ 7 and M^*> – 20.7 for z ~ 9 (68% confidence). This suggests that the downward luminosity evolution of Lyman break galaxies continues to z ~ 7, although our result is marginally consistent with the z ~ 6 luminosity function of Bouwens et al. In addition, we present newly acquired deep MMT/Megacam imaging of the z ~ 9 candidate JD2325+1433, first presented in Henry et al. The resulting weak but significant detection at i' indicates that this galaxy is most likely an interloper at z ~ 2.7.

Additional Information

© 2009. The American Astronomical Society. Received 2008 December 15; accepted 2009 March 19; published 2009 May 8. This work is funded in part by the University of California President's DissertationYear Fellowship. Observations reported here were obtained at the MMT Observatory, a joint facility of the Smithsonian Institution and the University of Arizona. The authors thank S. Furlanetto for helpful discussions, and K. Kornei and R. Bouwens for comments that improved this manuscript.

Attached Files

Published - Henry2009p4283Astrophys_J.pdf


Files (714.9 kB)
Name Size Download all
714.9 kB Preview Download

Additional details

August 21, 2023
October 18, 2023