TY - JOUR
T1 - Searching for z 7.7 Lyα emitters in the cosmos field with newfirm
AU - Krug, Hannah B.
AU - Veilleux, Sylvain
AU - Tilvi, Vithal
AU - Malhotra, Sangeeta
AU - Rhoads, James
AU - Hibon, Pascale
AU - Swaters, Rob
AU - Probst, Ron
AU - Dey, Arjun
AU - Dickinson, Mark
AU - Jannuzi, Buell T.
PY - 2012/2/1
Y1 - 2012/2/1
N2 - The study of Lyα emission in the high-redshift universe is a useful probe of the epoch of reionization, as the Lyα 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 Lyα emitters in the Cosmological Evolution Survey field. We have used two ultra-narrowband filters (filter width of 8-9 ) 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 Lyα emitters at z = 7.7; such ultra-narrowband imaging searches have proved to be excellent at detecting Lyα emitters. We found 5σ detections of four candidate Lyα emitters in a survey volume of 2.8 × 104Mpc3 (total survey area 760 arcmin2). Each candidate has a line flux greater than 8 × 10-18ergs-1cm-2. Using these results to construct a luminosity function and comparing to previously established Lyα 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.
AB - The study of Lyα emission in the high-redshift universe is a useful probe of the epoch of reionization, as the Lyα 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 Lyα emitters in the Cosmological Evolution Survey field. We have used two ultra-narrowband filters (filter width of 8-9 ) 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 Lyα emitters at z = 7.7; such ultra-narrowband imaging searches have proved to be excellent at detecting Lyα emitters. We found 5σ detections of four candidate Lyα emitters in a survey volume of 2.8 × 104Mpc3 (total survey area 760 arcmin2). Each candidate has a line flux greater than 8 × 10-18ergs-1cm-2. Using these results to construct a luminosity function and comparing to previously established Lyα 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.
KW - dark ages, reionization, first stars
KW - galaxies: high-redshift
KW - galaxies: luminosity function, mass function
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U2 - 10.1088/0004-637X/745/2/122
DO - 10.1088/0004-637X/745/2/122
M3 - Article
AN - SCOPUS:84855911731
SN - 0004-637X
VL - 745
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 122
ER -