Ly-alpha emitting galaxies at redshift z~4.5 in the LALA Cetus field

Abstract

We present a large sample of Ly-alpha emitting galaxies spectroscopically confirmed at z~4.5, based on IMACS spectroscopic observations of candidate LAEs in the LALA Cetus field. We identify 110 z~4.5 LAEs based on single line detections with no continuum emission blueward of the line. The Ly-alpha confirmation rate varies from <50% to 76% for candidates selected in different narrowband filters at slightly different redshifts. We find a drop in the LAE density at redshift 4.50+-0.03 from redshift 4.39-4.47 by a factor of 66%, which could be a large scale void in the distribution of star-forming galaxies (~18Mpc along the line of sight and ~80Mpc across). The sample includes many objects with equivalent widths >200A. These large EW candidates are spectroscopically confirmed at the same rate as candidates with more modest EWs. A composite spectrum of all 110 confirmed LAEs shows the characteristic asymmetry of the Ly-alpha line. It also places new and stringent upper limits on the CIV 1549/Ly-alpha and HeII 1640/Ly-alpha line ratios, providing a new upper limit on the fraction of active galactic nuclei in Ly-alpha selected galaxy samples, and on the contribution of Pop III populations. Finally, we calculate the Ly-alpha luminosity function for our z~4.5 sample, which is consistent with those at other redshifts, showing that there is no evolution in Ly-alpha luminosity function from z~3.1-6.6.

30 pages, 10 figures, ApJ submitted

References in corpus (10)

• The Subaru/XMM-Newton Deep Survey (SXDS). IV. Evolution of Lya Emitters from z=3.1 to 5.7 in the 1 deg^2 Field: Luminosity Functions and AGN
• The End of the Reionization Epoch Probed by Ly-alpha Emitters at z=6.5 in the Subaru Deep Field
• Ly-alpha Emission-Line Galaxies at z = 3.1 in the Extended Chandra Deep Field South
• A galaxy at a redshift z = 6.96
• A Luminosity Function of Lyman Alpha Emitting Galaxies at Redshift 4.5
• Effects of Dust Geometry in Lyman Alpha Galaxies at z = 4.4
• Clustering of Lyman alpha emitters at z ~ 4.5
• Lyman-alpha emission galaxies at a redshift of z = 5.7 in the FORS Deep Field
• The Wide Field Imager Lyman-Alpha Search (WFILAS) for Galaxies at Redshift ~5.7: II. Survey Design and Sample Analysis
• Chandra X-ray Sources in the LALA Cetus Field

Cited by in corpus (7)

• Onset of Cosmic Reionization: Evidence of An Ionized Bubble Merely 680 Myrs after the Big Bang
• The UV, Lyman-alpha, and dark matter halo properties of high redshift galaxies
• First Spectroscopic Confirmations of z ~ 7.0 Lya Emitting Galaxies in the LAGER Survey
• Lyman-Alpha Emitter Galaxies at z ~ 2.8 in the Extended Chandra Deep Field-South: I. Tracing the Large-Scale Structure via Lyman-Alpha Imaging
• Effect of Intergalactic Medium on the Observability of Lyman Alpha Emitters during Cosmic Reionization
• Ly$\alpha$ Emitters with Very Large Ly$\alpha$ Equivalent Widths, EW${}_0$(Ly$\alpha$) $\simeq 200-400$ Å, at $z\sim 2$
• Spitzer's View of the Candidate Cluster and Protocluster Catalog (CCPC)