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 Plus annual

Presents the access of premium content as premium feature

Premium Content

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 annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

The study of Ly-alpha emission in the high-redshift universe is a usefulprobe of the epoch of reionization, as the Ly-alpha line should be attenuatedby the intergalactic medium (IGM) at low to moderate neutral hydrogenfractions. Here we present the results of a deep and wide imaging search forLy-alpha emitters in the COSMOS field. We have used two ultra-narrowbandfilters (filter width of ~8-9 {\deg}A) on the NEWFIRM camera, installed on theMayall 4m telescope at Kitt Peak National Observatory, in order to isolateLy-alpha emitters at z = 7.7; such ultra-narrowband imaging searches haveproved to be excellent at detecting Ly-alpha emitters. We found 5-sigmadetections of four candidate Ly-alpha emitters in a survey volume of 2.8 x 10^4Mpc^3 (total survey area ~760 arcmin^2). Each candidate has a line flux greaterthan 8 x 10^-18 erg s^-1 cm^-2. Using these results to construct a luminosityfunction and comparing to previously established Ly-alpha luminosity functionsat z = 5.7 and z = 6.5, we find no conclusive evidence for evolution of theluminosity function between z = 5.7 and z = 7.7. Statistical Monte Carlosimulations suggest that half of these candidates are real z = 7.7 targets, andspectroscopic follow-up will be required to verify the redshift of thesecandidates. However, our results are consistent with no strong evolution in theneutral hydrogen fraction of the IGM between z = 5.7 and z = 7.7, even if onlyone or two of the z = 7.7 candidates are spectroscopically confirmed.

Searching for z~7.7 Lyman Alpha Emitters in the COSMOS Field with NEWFIRM