A Caltech Library Service

The Redshift Evolution of Rest-UV Spectroscopic Properties in Lyman-break Galaxies at z ~ 2–4

Du, Xinnan and Shapley, Alice E. and Reddy, Naveen A. and Jones, Tucker and Stark, Daniel P. and Steidel, Charles C. and Strom, Allison L. and Rudie, Gwen C. and Erb, Dawn K. and Ellis, Richard S. and Pettini, Max (2018) The Redshift Evolution of Rest-UV Spectroscopic Properties in Lyman-break Galaxies at z ~ 2–4. Astrophysical Journal, 860 (1). Art. No. 75. ISSN 1538-4357. doi:10.3847/1538-4357/aabfcf.

[img] PDF - Published Version
See Usage Policy.

[img] PDF - Accepted Version
See Usage Policy.


Use this Persistent URL to link to this item:


We present the first comprehensive evolutionary analysis of the rest-frame UV spectroscopic properties of star-forming galaxies at z ~ 2–4. We match samples at different redshifts in UV luminosity and stellar mass, and perform systematic measurements of spectral features and stellar population modeling. By creating composite spectra grouped according to Lyα equivalent width (EW) and various galaxy properties, we study the evolutionary trends among Lyα, low- and high-ionization interstellar (LIS and HIS) absorption features, and integrated galaxy properties. We also examine the redshift evolution of Lyα and LIS absorption kinematics, and fine-structure emission EWs. The connections among the strengths of Lyα, LIS lines, and dust extinction are redshift independent, as is the decoupling of the Lyα and HIS line strengths, and the bulk outflow kinematics as traced by the LIS lines. Stronger Lyα emission is observed at higher redshift at fixed UV luminosity, stellar mass, SFR, and age. Much of this variation in the average Lyα strength with redshift, and the variation in Lyα strength at fixed redshift, can be explained in terms of variations in the neutral gas covering fraction and/or dust content in the ISM and CGM. However, based on the connection between Lyα and C iii] emission strengths, we additionally find evidence for variations in the intrinsic production rate of Lyα photons at the highest Lyα EWs. The challenge now is to understand the observed evolution of the neutral gas covering fraction and dust extinction within a coherent model for galaxy formation, and make robust predictions for the escape of ionizing radiation at z > 6.

Item Type:Article
Related URLs:
URLURL TypeDescription Paper
Shapley, Alice E.0000-0003-3509-4855
Reddy, Naveen A.0000-0001-9687-4973
Jones, Tucker0000-0001-5860-3419
Steidel, Charles C.0000-0002-4834-7260
Strom, Allison L.0000-0001-6369-1636
Rudie, Gwen C.0000-0002-8459-5413
Erb, Dawn K.0000-0001-9714-2758
Ellis, Richard S.0000-0001-7782-7071
Pettini, Max0000-0002-5139-4359
Additional Information:© 2018 The American Astronomical Society. Received 2018 March 15; revised 2018 April 18; accepted 2018 April 19; published 2018 June 13. We acknowledge support from the David & Lucile Packard Foundation (A.E.S). We are grateful to the 3D-HST team for providing ancillary data on galaxy properties. This paper also includes data gathered with the 6.5 m Magellan Telescopes located at Las Campanas Observatory, Chile. We wish to extend special thanks to those of Hawaiian ancestry on whose sacred mountain we are privileged to be guests. Without their generous hospitality, most of the observations presented herein would not have been possible.
Group:Astronomy Department
Funding AgencyGrant Number
David and Lucile Packard FoundationUNSPECIFIED
Subject Keywords:galaxies: evolution – galaxies: high-redshift – galaxies: ISM
Issue or Number:1
Record Number:CaltechAUTHORS:20180613-094038182
Persistent URL:
Official Citation:Xinnan Du et al 2018 ApJ 860 75
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:87053
Deposited By: Tony Diaz
Deposited On:13 Jun 2018 16:50
Last Modified:15 Nov 2021 20:44

Repository Staff Only: item control page