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Title: SEARCHING FOR z {approx} 7.7 Ly{alpha} EMITTERS IN THE COSMOS FIELD WITH NEWFIRM

Journal Article · · Astrophysical Journal
;  [1]; ; ; ;  [2];  [3]; ; ;
  1. Department of Astronomy, University of Maryland, College Park, MD 20742 (United States)
  2. School of Earth and Space Exploration, Arizona State University, Tempe, AZ 85287 (United States)
  3. Gemini Observatory, c/o AURA, Casilla 603, La Serena (Chile)

The study of Ly{alpha} emission in the high-redshift universe is a useful probe of the epoch of reionization, as the Ly{alpha} line should be attenuated by the intergalactic medium (IGM) at low to moderate neutral hydrogen fractions. Here we present the results of a deep and wide imaging search for Ly{alpha} emitters in the Cosmological Evolution Survey field. We have used two ultra-narrowband filters (filter width of {approx}8-9 A) on the NOAO Extremely Wide-Field Infrared Mosaic camera, installed on the Mayall 4 m telescope at Kitt Peak National Observatory, in order to isolate Ly{alpha} emitters at z = 7.7; such ultra-narrowband imaging searches have proved to be excellent at detecting Ly{alpha} emitters. We found 5{sigma} detections of four candidate Ly{alpha} emitters in a survey volume of 2.8 Multiplication-Sign 10{sup 4} Mpc{sup 3} (total survey area {approx}760 arcmin{sup 2}). Each candidate has a line flux greater than 8 Multiplication-Sign 10{sup -18} erg s{sup -1} cm{sup -2}. Using these results to construct a luminosity function and comparing to previously established Ly{alpha} luminosity functions at z = 5.7 and z = 6.5, we find no conclusive evidence for evolution of the luminosity function between z = 5.7 and z = 7.7. Statistical Monte Carlo simulations suggest that half of these candidates are real z = 7.7 targets, and spectroscopic follow-up will be required to verify the redshift of these candidates. However, our results are consistent with no strong evolution in the neutral hydrogen fraction of the IGM between z = 5.7 and z = 7.7, even if only one or two of the z = 7.7 candidates are spectroscopically confirmed.

OSTI ID:
22011923
Journal Information:
Astrophysical Journal, Vol. 745, Issue 2; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 0004-637X
Country of Publication:
United States
Language:
English