A luminosity function of Lyα-emitting galaxies at z ≈ 4.5 1,2

Steve Dawson, James E. Rhoads, Sangeeta Malhotra, Daniel Stern, JunXian Wang, Arjun Dey, Hyron Spinrad, Buell T. Jannuzi

Research output: Contribution to journalArticle

84 Citations (Scopus)

Abstract

We present a catalog of 59 z ≈ 4.5 Lyα-emitting galaxies spectroscopically confirmed in a campaign of Keck DEIMOS follow-up observations to candidates selected in the Large Area Lya (LALA) narrowband imaging survey. We targeted 97 candidates for spectroscopic follow-up; by accounting for the variety of conditions under which we performed spectroscopy, we estimate a selection reliability of ∼76%. Together with our previous sample of Keck LRIS confirmations, the 59 sources confirmed herein bring the total catalog to 73 spectroscopically confirmed z ≈ 4.5 Lyαemitting galaxies in the ≈0.7deg2 covered by the LALA imaging. As with the Keck LRIS sample, we find that a nonnegligible fraction of the confirmed Lya lines have rest-frame equivalent widths (Wγrest) that exceed the maximum predicted for normal stellar populations: 17%-31% (93% confidence) of the detected galaxies show Wγrest > 190 Å, and 12%-27% (90%) confidence) show Wγrest > 240 ÅWe construct a luminosity function of z ≈ 4.5 Lyα emission lines for comparison to Lyα luminosity functions spanning 3.1 < z < 6.6. We find no significant evidence for Lyα luminosity function evolution from z ≈ 3 to z ≈ 6. This result supports the conclusion that the intergalactic medium remains largely reionized from the local universe out to z ≈ 6.5. It is somewhat at odds with the pronounced drop in the cosmic star formation rate density recently measured between z ∼ 3 and z ∼ 6 in continuum-selected Lyman-break galaxies, and therefore potentially sheds light on the relationship between the two populations.

Original languageEnglish (US)
Pages (from-to)1227-1240
Number of pages14
JournalAstrophysical Journal
Volume671
Issue number2
DOIs
StatePublished - Dec 20 2007

Fingerprint

luminosity
galaxies
catalogs
confidence
intergalactic media
star formation rate
spectroscopy
narrowband
universe
continuums
estimates
rate
comparison

Keywords

  • Cosmology: observations
  • Early universe
  • Galaxies: evolution
  • Galaxies: formation
  • Galaxies: high-redshift

ASJC Scopus subject areas

  • Space and Planetary Science

Cite this

Dawson, S., Rhoads, J. E., Malhotra, S., Stern, D., Wang, J., Dey, A., ... Jannuzi, B. T. (2007). A luminosity function of Lyα-emitting galaxies at z ≈ 4.5 1,2. Astrophysical Journal, 671(2), 1227-1240. https://doi.org/10.1086/522908

A luminosity function of Lyα-emitting galaxies at z ≈ 4.5 1,2. / Dawson, Steve; Rhoads, James E.; Malhotra, Sangeeta; Stern, Daniel; Wang, JunXian; Dey, Arjun; Spinrad, Hyron; Jannuzi, Buell T.

In: Astrophysical Journal, Vol. 671, No. 2, 20.12.2007, p. 1227-1240.

Research output: Contribution to journalArticle

Dawson, S, Rhoads, JE, Malhotra, S, Stern, D, Wang, J, Dey, A, Spinrad, H & Jannuzi, BT 2007, 'A luminosity function of Lyα-emitting galaxies at z ≈ 4.5 1,2', Astrophysical Journal, vol. 671, no. 2, pp. 1227-1240. https://doi.org/10.1086/522908
Dawson S, Rhoads JE, Malhotra S, Stern D, Wang J, Dey A et al. A luminosity function of Lyα-emitting galaxies at z ≈ 4.5 1,2. Astrophysical Journal. 2007 Dec 20;671(2):1227-1240. https://doi.org/10.1086/522908
Dawson, Steve ; Rhoads, James E. ; Malhotra, Sangeeta ; Stern, Daniel ; Wang, JunXian ; Dey, Arjun ; Spinrad, Hyron ; Jannuzi, Buell T. / A luminosity function of Lyα-emitting galaxies at z ≈ 4.5 1,2. In: Astrophysical Journal. 2007 ; Vol. 671, No. 2. pp. 1227-1240.
@article{d48396ef3984463c845e6a2ee9ba6f22,
title = "A luminosity function of Lyα-emitting galaxies at z ≈ 4.5 1,2",
abstract = "We present a catalog of 59 z ≈ 4.5 Lyα-emitting galaxies spectroscopically confirmed in a campaign of Keck DEIMOS follow-up observations to candidates selected in the Large Area Lya (LALA) narrowband imaging survey. We targeted 97 candidates for spectroscopic follow-up; by accounting for the variety of conditions under which we performed spectroscopy, we estimate a selection reliability of ∼76{\%}. Together with our previous sample of Keck LRIS confirmations, the 59 sources confirmed herein bring the total catalog to 73 spectroscopically confirmed z ≈ 4.5 Lyαemitting galaxies in the ≈0.7deg2 covered by the LALA imaging. As with the Keck LRIS sample, we find that a nonnegligible fraction of the confirmed Lya lines have rest-frame equivalent widths (Wγrest) that exceed the maximum predicted for normal stellar populations: 17{\%}-31{\%} (93{\%} confidence) of the detected galaxies show Wγrest > 190 {\AA}, and 12{\%}-27{\%} (90{\%}) confidence) show Wγrest > 240 {\AA}We construct a luminosity function of z ≈ 4.5 Lyα emission lines for comparison to Lyα luminosity functions spanning 3.1 < z < 6.6. We find no significant evidence for Lyα luminosity function evolution from z ≈ 3 to z ≈ 6. This result supports the conclusion that the intergalactic medium remains largely reionized from the local universe out to z ≈ 6.5. It is somewhat at odds with the pronounced drop in the cosmic star formation rate density recently measured between z ∼ 3 and z ∼ 6 in continuum-selected Lyman-break galaxies, and therefore potentially sheds light on the relationship between the two populations.",
keywords = "Cosmology: observations, Early universe, Galaxies: evolution, Galaxies: formation, Galaxies: high-redshift",
author = "Steve Dawson and Rhoads, {James E.} and Sangeeta Malhotra and Daniel Stern and JunXian Wang and Arjun Dey and Hyron Spinrad and Jannuzi, {Buell T.}",
year = "2007",
month = "12",
day = "20",
doi = "10.1086/522908",
language = "English (US)",
volume = "671",
pages = "1227--1240",
journal = "Astrophysical Journal",
issn = "0004-637X",
publisher = "IOP Publishing Ltd.",
number = "2",

}

TY - JOUR

T1 - A luminosity function of Lyα-emitting galaxies at z ≈ 4.5 1,2

AU - Dawson, Steve

AU - Rhoads, James E.

AU - Malhotra, Sangeeta

AU - Stern, Daniel

AU - Wang, JunXian

AU - Dey, Arjun

AU - Spinrad, Hyron

AU - Jannuzi, Buell T.

PY - 2007/12/20

Y1 - 2007/12/20

N2 - We present a catalog of 59 z ≈ 4.5 Lyα-emitting galaxies spectroscopically confirmed in a campaign of Keck DEIMOS follow-up observations to candidates selected in the Large Area Lya (LALA) narrowband imaging survey. We targeted 97 candidates for spectroscopic follow-up; by accounting for the variety of conditions under which we performed spectroscopy, we estimate a selection reliability of ∼76%. Together with our previous sample of Keck LRIS confirmations, the 59 sources confirmed herein bring the total catalog to 73 spectroscopically confirmed z ≈ 4.5 Lyαemitting galaxies in the ≈0.7deg2 covered by the LALA imaging. As with the Keck LRIS sample, we find that a nonnegligible fraction of the confirmed Lya lines have rest-frame equivalent widths (Wγrest) that exceed the maximum predicted for normal stellar populations: 17%-31% (93% confidence) of the detected galaxies show Wγrest > 190 Å, and 12%-27% (90%) confidence) show Wγrest > 240 ÅWe construct a luminosity function of z ≈ 4.5 Lyα emission lines for comparison to Lyα luminosity functions spanning 3.1 < z < 6.6. We find no significant evidence for Lyα luminosity function evolution from z ≈ 3 to z ≈ 6. This result supports the conclusion that the intergalactic medium remains largely reionized from the local universe out to z ≈ 6.5. It is somewhat at odds with the pronounced drop in the cosmic star formation rate density recently measured between z ∼ 3 and z ∼ 6 in continuum-selected Lyman-break galaxies, and therefore potentially sheds light on the relationship between the two populations.

AB - We present a catalog of 59 z ≈ 4.5 Lyα-emitting galaxies spectroscopically confirmed in a campaign of Keck DEIMOS follow-up observations to candidates selected in the Large Area Lya (LALA) narrowband imaging survey. We targeted 97 candidates for spectroscopic follow-up; by accounting for the variety of conditions under which we performed spectroscopy, we estimate a selection reliability of ∼76%. Together with our previous sample of Keck LRIS confirmations, the 59 sources confirmed herein bring the total catalog to 73 spectroscopically confirmed z ≈ 4.5 Lyαemitting galaxies in the ≈0.7deg2 covered by the LALA imaging. As with the Keck LRIS sample, we find that a nonnegligible fraction of the confirmed Lya lines have rest-frame equivalent widths (Wγrest) that exceed the maximum predicted for normal stellar populations: 17%-31% (93% confidence) of the detected galaxies show Wγrest > 190 Å, and 12%-27% (90%) confidence) show Wγrest > 240 ÅWe construct a luminosity function of z ≈ 4.5 Lyα emission lines for comparison to Lyα luminosity functions spanning 3.1 < z < 6.6. We find no significant evidence for Lyα luminosity function evolution from z ≈ 3 to z ≈ 6. This result supports the conclusion that the intergalactic medium remains largely reionized from the local universe out to z ≈ 6.5. It is somewhat at odds with the pronounced drop in the cosmic star formation rate density recently measured between z ∼ 3 and z ∼ 6 in continuum-selected Lyman-break galaxies, and therefore potentially sheds light on the relationship between the two populations.

KW - Cosmology: observations

KW - Early universe

KW - Galaxies: evolution

KW - Galaxies: formation

KW - Galaxies: high-redshift

UR - http://www.scopus.com/inward/record.url?scp=40249097459&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=40249097459&partnerID=8YFLogxK

U2 - 10.1086/522908

DO - 10.1086/522908

M3 - Article

AN - SCOPUS:40249097459

VL - 671

SP - 1227

EP - 1240

JO - Astrophysical Journal

JF - Astrophysical Journal

SN - 0004-637X

IS - 2

ER -