%0 Generic %1 Dressler2011 %A Dressler, Alan %A Martin, Crystal L. %A Henry, Alaina %A Sawicki, Marcin %A McCarthy, Patrick %D 2011 %K high-z lya reionization %T Detections of Faint Lyman-alpha Emitters at z = 5.7: Galaxy Building Blocks and Engines of Reionization %U http://arxiv.org/abs/1104.2900 %X We report results of a unprecedentedly deep, blind search for Lyman-alpha emitters (LAEs) at z = 5.75 using IMACS, the Inamori-Magellan Areal Camera & Spectrograph, 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 ~20 hours of integration per field in excellent seeing led to the detection of single-emission-line sources as faint as F ~ 2 x 10^-18 ergs s^-1 cm^-2, a sensitivity 5 times deeper than our first search (Martin et al. 2008). Making reasonable corrections for foreground interlopers, we find a steep rise in the number counts of LAEs in our 110 sq arcmin survey area, from n ~ 16 at F = 10^-17.0 ergs s^-1 cm^-2 to n ~ 122 at F = 10^-17.6 (2.5 x 10^-18 ergs s^-1 cm^-2. At this flux the putative LAEs have reached a surface density of ~1 per sq arcminute -- a comoving volume density of 4 x 10^-3 Mpc^-3, several times the density of L* galaxies today. The Lyman-continuum flux from these LAEs should be approaching the critical flux density required to complete reionization at this epoch, using conservative assumptions about neutral-gas clumpiness, and Lyman-alpha and Lyman-continuum escape fractions. Such faint LAEs are good candidates for building blocks of stellar mass ~10^8-9 Msun for the young galaxies of this epoch.

@misc{Dressler2011, abstract = { We report results of a unprecedentedly deep, blind search for Lyman-alpha emitters (LAEs) at z = 5.75 using IMACS, the Inamori-Magellan Areal Camera & Spectrograph, 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 ~20 hours of integration per field in excellent seeing led to the detection of single-emission-line sources as faint as F ~ 2 x 10^{-18} ergs s^{-1} cm^{-2}, a sensitivity 5 times deeper than our first search (Martin et al. 2008). Making reasonable corrections for foreground interlopers, we find a steep rise in the number counts of LAEs in our 110 sq arcmin survey area, from n ~ 16 at F = 10^{-17.0} ergs s^{-1} cm^{-2} to n ~ 122 at F = 10^{-17.6} (2.5 x 10^{-18} ergs s^{-1} cm^{-2}. At this flux the putative LAEs have reached a surface density of ~1 per sq arcminute -- a comoving volume density of 4 x 10^{-3} Mpc^{-3}, several times the density of L* galaxies today. The Lyman-continuum flux from these LAEs should be approaching the critical flux density required to complete reionization at this epoch, using conservative assumptions about neutral-gas clumpiness, and Lyman-alpha and Lyman-continuum escape fractions. Such faint LAEs are good candidates for building blocks of stellar mass ~10^{8-9} Msun for the young galaxies of this epoch. }, added-at = {2011-04-18T09:26:04.000+0200}, author = {Dressler, Alan and Martin, Crystal L. and Henry, Alaina and Sawicki, Marcin and McCarthy, Patrick}, biburl = {https://www.bibsonomy.org/bibtex/2c2d0d1442b241c445ce695c161d8f625/miki}, description = {[1104.2900] Detections of Faint Lyman-alpha Emitters at z = 5.7: Galaxy Building Blocks and Engines of Reionization}, interhash = {1c1f62603d7d2275e4f48f05ca8970fc}, intrahash = {c2d0d1442b241c445ce695c161d8f625}, keywords = {high-z lya reionization}, note = {cite arxiv:1104.2900 Comment: 15 pages, 12 figures. Submitted to ApJ}, timestamp = {2011-04-18T09:26:04.000+0200}, title = {Detections of Faint Lyman-alpha Emitters at z = 5.7: Galaxy Building Blocks and Engines of Reionization}, url = {http://arxiv.org/abs/1104.2900}, year = 2011 }