English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Tools annual

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools monthly

Global: Zendy Plus monthly

Presents the access of premium content as premium feature

Premium Content

Global: Zendy Plus annual

Global: Zendy Free Plan

We use all available deep optical ACS and near-IR data over both the HUDF andthe two GOODS fields to search for star-forming galaxies at z>~7 and constrainthe UV LF within the first 700 Myrs. Our data set includes ~23 arcmin^2 of deepNICMOS J+H data and ~248 arcmin^2 of ground-based (ISAAC+MOIRCS) data,coincident with ACS optical data of greater or equal depths. In total, we find8 <z>~7.3 z-dropouts in our search fields, but no z~9 J-dropout candidates. Acareful consideration of a wide variety of different contaminants suggest anoverall contamination level of just ~12% for our z-dropout selection. Afterperforming detailed simulations to accurately estimate the selection volumes,we derive constraints on the UV LFs at z~7 and z~9. For a faint-end slopealpha=-1.74, our most likely values for M*(UV) and phi* at z~7 are -19.8+/-0.4mag and 1.1_{-0.7}^{+1.7} x 10^{-3} Mpc^{-3}, respectively. Our search resultsfor z~9 J-dropouts set a 1 sigma lower limit on M*(UV) of -19.6 mag assumingthat phi* and alpha are the same as their values at slightly later times. Thislower limit on M*(UV) is 1.4 mag fainter than our best-fit value at z~4,suggesting that the UV LF has undergone substantial evolution over this timeperiod. No evolution is ruled out at 99% confidence from z~7 to z~6 and at 80%confidence from z~9 to z~7. The inferred brightening in M*(UV) with redshift(i.e., M*(UV) = (-21.02+/-0.09) + (0.36+/-0.08)(z - 3.8)) matches the evolutionexpected in the halo mass function, if the mass-to-light ratio of halos evolvesas ~(1+z)**{-1}. Finally, we consider the shape of the UV LF at z>~5 anddiscuss the implications of the Schechter-like form of the observed LFs,particularly the unexpected abrupt cut-off at the bright end.

z~7-10 Galaxies in the HUDF and GOODS fields, and their UV Luminosity Functions