DETECTIONS OF FAINT Ly{alpha} EMITTERS AT z = 5.7: GALAXY BUILDING BLOCKS AND ENGINES OF REIONIZATION

Journal Article · Thu Oct 20 04:00:00 EDT 2011 · Astrophysical Journal

DOI:https://doi.org/10.1088/0004-637X/740/2/71; COUNTRY OF INPUT: INTERNATIONAL ATOMIC ENERGY AGENCY (IAEA)· OSTI ID:21587383

Dressler, Alan; McCarthy, Patrick ^[1]; Martin, Crystal L; Henry, Alaina ^[2]; Sawicki, Marcin ^[3]

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1. Carnegie Observatories, 813 Santa Barbara St., Pasadena, CA 91101-1292 (United States)
2. Department of Physics, University of California, Santa Barbara, CA 93106 (United States)
3. Department of Astronomy and Physics, St. Mary's University, 923 Robie Street, Halifax, N. S., B3H 3C3 (Canada)

We report results of an unprecedentedly deep, blind search for Ly{alpha} emitters (LAEs) at z = 5.7 using the Inamori-Magellan Areal Camera and Spectrograph (IMACS), with the goal of identifying missing sources of reionization that could also be basic building blocks for today's L* galaxies. We describe how improvements in wide field imaging with the Baade telescope, upgrades to IMACS, and the accumulation of {approx}20 hr of integration per field in excellent seeing led to the detection of single-emission-line sources as faint as F {approx} 2 x 10{sup -18} erg s{sup -1} cm{sup -2}, a sensitivity five times deeper than our first search. A reasonable correction for foreground interlopers implies a steep rise of approximately an order of magnitude in source density for a factor of four drop in flux, from F = 10{sup -17.0} erg s{sup -1} cm{sup -2} to F = 10{sup -17.6} (2.5 x 10{sup -18}) erg s{sup -1} cm{sup -2}. At this flux the putative LAEs have reached a surface density of {approx}1 arcmin{sup -2}-a comoving volume density of 4 x 10{sup -3} Mpc{sup -3}, several times the density of L* galaxies today. Such a population of faint LAEs would account for a significant fraction of the critical flux density required to complete reionization at this epoch, and would be good candidates for building blocks of stellar mass {approx}10{sup 8}-10{sup 9} M{sub sun} for the young galaxies of this epoch.

• OSTI ID: 21587383
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 740; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
DENSITY
DETECTION
GALAXIES
LYMAN LINES
PHYSICAL PROPERTIES
STARS