Reionization and Galaxy Evolution Probed by z = 7 Lyα Emitters

By K. Ota, M. Iye, N. Kashikawa, K. Shimasaku, Masakazu A. R. Kobayashi, T. Totani, M. Nagashima, T. Morokuma, H. Furusawa, T. Hattori and 3 more. 2007

160 citations recorded by the source corpus.

We have performed narrowband NB973 (bandwidth 200 Å centered at 9755 Å) imaging of the Subaru Deep Field (SDF) and found two z = 7 Lyα emitter (LAE) candidates down to NB973 = 24.9. Carrying out deep follow-up spectroscopy, we identified one of them as a real z = 6.96 LAE. This has established a new redshift record, showing that galaxy formation was in progress just 750 Myr after the big bang. Meanwhile, the Lyα line luminosity function of LAEs is known to decline from z = 5.7 to 6.6 in the SDF; L* at z = 6.6 is 40%-60% that at z = 5.7. We also confirm that the number density of z = 7 LAEs is only 17% of the density at z = 6.6 comparing the latest SDF LAE samples. This series of significant decreases in LAE density with increasing redshift could be the result of galaxy evolution during these epochs. However, using the UV continuum luminosity functions of LAEs and Lyman break galaxies, and a LAE evolution model based on hierarchical clustering, we find that galaxy evolution alone cannot entirely explain the decrease in density. This extra density deficit might reflect the attenuation of the Lyα photons from LAEs by the neutral hydrogen possibly left at the last stage of cosmic reionization at z ∼ 6-7.

Subfields: Astronomy and Astrophysics, Instrumentation

View Paper: https://www.semanticscholar.org/paper/bd046e5af50ac4b644685a27c82482e622dd68ea

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Astronomy and Astrophysics

In Instrumentation

Citations in the corpus

Keck spectroscopy of faint 3 < z < 7 Lyman break galaxies – I. New constraints on cosmic reionization from the luminosity and redshift-dependent fraction of Lyman α emission (2010, methodology): “While these NICMOS dropouts are generally not as robust as the z drops being identified with WFC3 (see Bouwens et al. 2009a), the lack of Lyα is tantalizing in light of the narrowband LAE results (Ota et al. 2008).”
COMPLETING THE CENSUS OF Lyα EMITTERS AT THE REIONIZATION EPOCH (2011, background): “The Lyα luminosity density of LAEs did not change from z = 3 to z = 5.7, and it gradually decreased from z = 5.7 to 7 (Ota et al. 2008).”
The contribution of high-redshift galaxies to cosmic reionization: New results from deep WFC3 imaging of the Hubble Ultra Deep Field (2009, background): “…searches have also proved successful in isolating the Lyman-α emission line in redshift slices between z = 3 and z = 7 (e.g., Rhoads et al. 2003, Ota et al. 2008, Smith & Jarvis 2007, Ouchi et al. 2008), although such searches at z > 7 have yet to yield plausible candidates (e.g. Willis et al.…”
STATISTICS OF 207 Lyα EMITTERS AT A REDSHIFT NEAR 7: CONSTRAINTS ON REIONIZATION AND GALAXY FORMATION MODELS (2010, methodology): “Lyα LFs at these redshifts are estimated with a reliable but only 1-2 LAEs at z = 7.0 (Iye et al. 2006; Ota et al. 2008) and with relatively less-reliable z ≃ 7.7 candidates with no spectroscopic confirmation (Hibon et al. 2010; Tilvi et al. 2010).”
Cosmogenic neutrinos: parameter space and detectabilty from PeV to ZeV (2010, background): “Above z ∼ 1, the results of the different studies disagree on the shape of the SFR, though a tendency towards a plateau in the range of z ∼ 1 − 4 and then a more or less steep decrease for z & 4 seems to emerge (Hopkins and Beacom, 2006; Li, 2008; Ota et al., 2008; Yüksel et al., 2008; Wang and Dai”
Full-data Results of Hubble Frontier Fields: UV Luminosity Functions at z ∼ 6–10 and a Consistent Picture of Cosmic Reionization (2017, unknown): “…al. (2011); Carilli et al. (2010); Chornock et al. (2013, 2014); Dijkstra et al. (2011); Konno et al. (2014); McGreer et al. (2011); McQuinn et al. (2007, 2008); Mesinger & Furlanetto (2008); Mesinger (2010); Ouchi et al. (2010); Ota et al. (2008); Patel et al. (2010); Totani et al. (2006, 2014).”
NEW CONSTRAINTS ON COSMIC REIONIZATION FROM THE 2012 HUBBLE ULTRA DEEP FIELD CAMPAIGN (2013, unknown): “Ota et al. (2008) examined thez = 7 window.”
THE STAR FORMATION RATE IN THE REIONIZATION ERA AS INDICATED BY GAMMA-RAY BURSTS (2009, unknown): “…-4 10 -3 10 -2 0.1 1 ρ. * [ M yr -1 M pc -3 ] 13 8 4 2 1 0.6 t [Gyr] GRB: (evolution corrected) LBG: Bouwens et al. (2008) B08 (LF integrated) LAE: Ota et al. (2008) ρc (C / fesc = 40, 30, 20) higher, although it is difficult to draw definite conclusions, due to the limited statistics and…”
SPECTROSCOPIC CONFIRMATION OF z ∼ 7 LYMAN BREAK GALAXIES: PROBING THE EARLIEST GALAXIES AND THE EPOCH OF REIONIZATION (2011, methodology): “For a comparison, Ota et al. obtained an estimate of χz=7HI ∼ 0.32− 0.62 from the lack of Lyα emitters in the deep NB973 survey of the Subaru Deep Field (Ota et al. 2008,2010) and using the Santos 2004 reionization models.”
ON THE REDSHIFT EVOLUTION OF THE Lyα ESCAPE FRACTION AND THE DUST CONTENT OF GALAXIES (2010, methodology): “We adopt the z = 6.5 point from Ouchi et al. (2010, which includes the sample of Kashikawa et al. 2006), and the measurement of Iye et al. (2006) at z = 7.0, which has also been compiled in Ota et al. (2008).”
HUBBLE FRONTIER FIELDS FIRST COMPLETE CLUSTER DATA: FAINT GALAXIES AT z ∼ 5–10 FOR UV LUMINOSITY FUNCTIONS AND COSMIC REIONIZATION (2014, background): “…Bolton et al. 2011), Lyα damping wing absorption in a GRB spectrum (Totani et al. 2006; McQuinn et al. 2008), evolution of the Lyα luminosity function and Lyα emitter clustering (Ota et al. 2008; Ouchi et al. 2010; Konno et al. 2014), and the Lyα emitting galaxy fraction evolution (Pentericci et…”
NEW OBSERVATIONS OF z ∼ 7 GALAXIES: EVIDENCE FOR A PATCHY REIONIZATION (2014, background): “…studying the reionization history of the Universe using Lyα emitting galaxies is to determine the evolution of the Lyα luminosity function and the clustering properties of narrow band selected Lyα emitters (LAEs e.g. Ota et al. 2008, Ouchi et a. 2010; Kashikawa et al. 2011, Clements et al. 2012).”
LARGE AREA SURVEY FOR z = 7 GALAXIES IN SDF AND GOODS-N: IMPLICATIONS FOR GALAXY FORMATION AND COSMIC REIONIZATION (2009, methodology): “It would provide signatures of the neutral fraction evolution that are claimed by Iye et al. (2006) and Ota et al. (2008) who find significantly less number of LAEs at z ∼ 7 than z ∼ 6.”
GRB 080913 AT REDSHIFT 6.7 (2008, background): “A significantly high neutral fraction of IGM at z & 6.7 has also been implied from evidence for the GP damping wing in the spectra of z=6 quasars (Mesinger & Haiman 2004, 2007) and the luminosity function evolution of Ly-α emitters (Kobayashi et al. 2007; Ota et al. 2008).”
Revealing the High-Redshift Star Formation Rate with Gamma-Ray Bursts (2008, methodology): “The cosmic star formation rate (SFR) measurements from the compilation of Hopkins & Beacom (2006) are shown, along with new high-z measurements based on observations of color-selected Lyman Break Galaxies (LBG) (Bouwens et al. 2008; Mannucci et al. 2007; Verma et al. 2007) and Lyα Emitters (LAE) (Ot”