Complex Lyman Alpha Profiles in Redshift 6.6 Ultraluminous Lyman Alpha Emitters

Abstract

We report on a search for ultraluminous Lyman alpha emitting galaxies (LAEs) at z=6.6 using the NB921 filter on Hyper Suprime-Cam on the Subaru telescope. We searched a 30 degree squared area around the North Ecliptic Pole, which we observed in broadband g', r', i', z', and y' and narrowband NB816 and NB921, for sources with NB921 < 23.5 and z' - NB921 > 1.3. This corresponds to a selection of log L(Ly-alpha) > 43.5 erg/s. We followed up seven candidate LAEs (out of thirteen) with the Keck DEIMOS spectrograph and confirmed five z=6.6 LAEs, one z=6.6 AGN with a broad Ly-alpha line and a strong red continuum, and one low-redshift ([OIII]5007) galaxy. The five ultraluminous LAEs have wider line profiles than lower luminosity LAEs, and one source, NEPLA4, has a complex line profile similar to that of COLA1. In combination with previous results, we show that the line profiles of the z=6.6 ultraluminous LAEs are systematically different than those of lower luminosity LAEs at this redshift. This result suggests that ultraluminous LAEs generate highly ionized regions of the intergalactic medium in their vicinity that allow the full Lyman alpha profile of the galaxy---including any blue wings---to be visible. If this interpretation is correct, then ultraluminous LAEs offer a unique opportunity to determine the properties of the ionized zones around them, which will help in understanding the ionization of the z ~ 7 intergalactic medium. A simple calculation gives a very rough estimate of 0.015 for the escape fraction of ionizing photons, but more sophisticated calculations are needed to fully characterize the uncertainties.

arXiv commentAccepted for publication in ApJ. 13 pages, 13 figures

References in corpus (36)

• New Insight on Galaxy Formation and Evolution from Keck Spectroscopy of the Hawaii Deep Fields
• UV Luminosity Functions at redshifts z~4 to z~10: 10000 Galaxies from HST Legacy Fields
• The Evolution of the Galaxy Rest-Frame Ultraviolet Luminosity Function Over the First Two Billion Years
• Statistics of 207 Lya Emitters at a Redshift Near 7: Constraints on Reionization and Galaxy Formation Models
• Keck Spectroscopy of Faint 3<z<7 Lyman Break Galaxies: - I. New constraints on cosmic reionisation from the luminosity and redshift-dependent fraction of Lyman-alpha emission
• eROSITA Science Book: Mapping the Structure of the Energetic Universe
• A new multi-field determination of the galaxy luminosity function at z=7-9 incorporating the 2012 Hubble Ultra Deep Field imaging
• Reionization of the Intergalactic Medium and the Damping Wing of the Gunn-Peterson Trough
• Lyman-alpha and CIII] Emission in z=7-9 Galaxies: Accelerated Reionization Around Luminous Star Forming Systems?
• Early star-forming galaxies and the reionization of the Universe
• Evidence for PopIII-like stellar populations in the most luminous Lyman-$\alpha$ emitters at the epoch of re-ionisation: spectroscopic confirmation
• Pan-STARRS Photometric and Astrometric Calibration
• Lyman-alpha Emission from a Luminous z=8.68 Galaxy: Implications for Galaxies as Tracers of Cosmic Reionization
• Spectroscopic detection of CIV in a galaxy at z=7.045: Implications for the ionizing spectra of reionization-era galaxies
• Z > 7 galaxies with red Spitzer/IRAC [3.6]-[4.5] colors in the full CANDELS data set: the brightest-known galaxies at Z ~ 7-9 and a probable spectroscopic confirmation at Z=7.48
• Subaru high-z exploration of low-luminosity quasars (SHELLQs). I. Discovery of 15 quasars and bright galaxies at 5.7 < z < 6.9
• An Atlas of z=5.7 and z=6.5 Ly alpha Emitters
• Identification of the brightest Lyα emitters at z=6.6: implications for the evolution of the luminosity function in the re-ionisation era
• Accelerated Evolution of Ly$\alpha$ Luminosity Function at $\text{z}\gtrsim 7$ Revealed by the Subaru Ultra-Deep Survey for Ly$\alpha$ Emitters at $\text{z}=7.3$
• Pan-STARRS Pixel Processing: Detrending, Warping, Stacking
• The lack of intense Lyman~alpha in ultradeep spectra of z=7 candidates in GOODS-S: imprint of reionization?
• First Results from the Lyman Alpha Galaxies in the Epoch of Reionization (LAGER) Survey: Cosmological Reionization at z ~ 7
• Lyman-alpha emission properties of simulated galaxies: interstellar medium structure and inclination effects
• The Detectability of High Redshift Lyman Alpha Emission Lines Prior to the Reionization of the Universe
• Quasar Strömgren Spheres Before Cosmological Reionization
• Pan-STARRS Pixel Analysis : Source Detection and Characterization
• The Kinematics of Multiple-Peaked Ly-alpha Emission in Star-Forming Galaxies at z~2-3
• The Lyman-alpha luminosity function at z=5.7-6.6 and the steep drop of the faint end: implications for reionization
• The CALYMHA survey: Lya luminosity function and global escape fraction of Lya photons at z=2.23
• ALMA reveals metals yet no dust within multiple components in CR7
• Candidate Type II Quasars at 2 < z < 4.3 in the Sloan Digital Sky Survey III
• Spectroscopic properties of luminous Lyman-α emitters at $z\approx 6-7$ and comparison to the Lyman-break population
• Constraining Reionization with the Evolution of the Luminosity Function of Lyman Alpha mitting Galaxies
• An Ultraluminous Lyman Alpha Emitter with a Blue Wing at z=6.6
• A High Space Density of Luminous Lyman Alpha Emitters at z~6.5
• Profiles of Lymanα Emission Lines

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