Stellar Populations of Lyα-emitting Galaxies in the HETDEX Survey. I. An Analysis of LAEs in the GOODS-N Field

We present the results of a stellar population analysis of 72 Lyα-emitting galaxies (LAEs) in GOODS-N at 1.9 < z < 3.5 spectroscopically identified by the Hobby−Eberly Telescope Dark Energy Experiment (HETDEX). We provide a method for connecting emission-line detections from the blind spectroscopic survey to imaging counterparts, a crucial tool needed as HETDEX builds a massive database of ∼1 million Lyα detections. Using photometric data spanning as many as 11 filters covering 0.4 < λ (μm) < 4.5 from the Hubble Space Telescope and Spitzer Space Telescope, we study the objects’ global properties and explore which properties impact the strength of Lyα emission. We measure a median stellar mass of 0.8−0.5+2.9×109M⊙ and conclude that the physical properties of HETDEX spectroscopically selected LAEs are comparable to LAEs selected by previous deep narrowband studies. We find that stellar mass and star formation rate correlate strongly with the Lyα equivalent width. We then use a known sample of z > 7 LAEs to perform a protostudy of predicting Lyα emission from galaxies in the epoch of reionization, finding agreement at the 1σ level between prediction and observation for the majority of strong emitters.

[1]  A. Coil,et al.  The Effects of Stellar Population and Gas Covering Fraction on the Emergent Lyα Emission of High-redshift Galaxies , 2021, The Astrophysical Journal.

[2]  L. Y. Aaron Yung,et al.  A Census of the Bright z = 8.5–11 Universe with the Hubble and Spitzer Space Telescopes in the CANDELS Fields , 2021, The Astrophysical Journal.

[3]  Brianna P. Thomas,et al.  The Hobby–Eberly Telescope Dark Energy Experiment (HETDEX) Survey Design, Reductions, and Detections , 2021, The Astrophysical Journal.

[4]  L. Ramsey,et al.  The HETDEX Instrumentation: Hobby–Eberly Telescope Wide-field Upgrade and VIRUS , 2021, The Astronomical Journal.

[5]  A. Dey,et al.  The Role of Dust, UV Luminosity and Large-scale Environment on the Escape of Lyα Photons: A Case Study of a Protocluster Field at z = 3.1 , 2021, The Astrophysical Journal.

[6]  Ariel G. S'anchez,et al.  Correcting correlation functions for redshift-dependent interloper contamination , 2021, Monthly Notices of the Royal Astronomical Society.

[7]  T. Nagao,et al.  SILVERRUSH X: Machine Learning-aided Selection of 9318 LAEs at z = 2.2, 3.3, 4.9, 5.7, 6.6, and 7.0 from the HSC SSP and CHORUS Survey Data , 2021, The Astrophysical Journal.

[8]  L. Wisotzki,et al.  The HETDEX Survey: The Lyα Escape Fraction from 3D-HST Emission-Line Galaxies at z ∼ 2 , 2021, The Astrophysical Journal.

[9]  L. Infante,et al.  Correlations between H α equivalent width and galaxy properties at z = 0.47: Physical or selection-driven? , 2021, 2103.10959.

[10]  R. Naidu,et al.  The X-SHOOTER Lyman α survey at z = 2 (XLS-z2) I: what makes a galaxy a Lyman α emitter? , 2021, Monthly Notices of the Royal Astronomical Society.

[11]  M. Ouchi,et al.  Observations of the Lyman-α Universe , 2020, Annual Review of Astronomy and Astrophysics.

[12]  S. Finkelstein,et al.  Texas Spectroscopic Search for Lyα Emission at the End of Reionization. III. The Lyα Equivalent-width Distribution and Ionized Structures at z > 7 , 2020, The Astrophysical Journal.

[13]  Jaime Fern'andez del R'io,et al.  Array programming with NumPy , 2020, Nature.

[14]  D. Sobral,et al.  The evolution of rest-frame UV properties, Ly α EWs, and the SFR–stellar mass relation at z ∼ 2–6 for SC4K LAEs , 2019, Monthly Notices of the Royal Astronomical Society.

[15]  A. Strom,et al.  Predicting Lyα Emission from Galaxies via Empirical Markers of Production and Escape in the KBSS , 2019, The Astrophysical Journal.

[16]  B. Garilli,et al.  The VANDELS survey: the role of ISM and galaxy physical properties in the escape of Lyα emission in z ∼ 3.5 star-forming galaxies , 2019, Astronomy & Astrophysics.

[17]  S. Finkelstein,et al.  Conditions for Reionizing the Universe with a Low Galaxy Ionizing Photon Escape Fraction , 2019, The Astrophysical Journal.

[18]  et al,et al.  Gaia Data Release 2 , 2018, Astronomy & Astrophysics.

[19]  J. Brinchmann,et al.  The MUSE Hubble Ultra Deep Field Survey , 2018, Astronomy & Astrophysics.

[20]  R. Ellis,et al.  The Redshift Evolution of Rest-UV Spectroscopic Properties in Lyman-break Galaxies at z ∼ 2–4 , 2018, The Astrophysical Journal.

[21]  S. Finkelstein,et al.  Texas Spectroscopic Search for Lyα Emission at the End of Reionization I. Constraining the Lyα Equivalent-width Distribution at 6.0 < z < 7.0 , 2018, The Astrophysical Journal.

[22]  R. Davé,et al.  Inferring the star formation histories of massive quiescent galaxies with bagpipes: evidence for multiple quenching mechanisms , 2017, Monthly Notices of the Royal Astronomical Society.

[23]  D. Sobral,et al.  Slicing COSMOS with SC4K: the evolution of typical Ly α emitters and the Ly α escape fraction from z ∼ 2 to 6 , 2017, 1712.04451.

[24]  A. Coil,et al.  The MOSDEF Survey: A Stellar Mass–SFR–Metallicity Relation Exists at z ∼ 2.3 , 2017, 1711.00224.

[25]  J. Silverman,et al.  The Stellar Mass, Star Formation Rate and Dark Matter Halo Properties of LAEs at $z\sim2$ , 2017, 1707.09373.

[26]  G. Blanc,et al.  A Comprehensive Study of Lyα Emission in the High-redshift Galaxy Population , 2017, 1706.01886.

[27]  N. Kashikawa,et al.  Direct evidence for Ly$\boldsymbol{\alpha }$ depletion in the protocluster core , 2017, 1702.00100.

[28]  Benjamin D. Johnson,et al.  Deriving Physical Properties from Broadband Photometry with Prospector: Description of the Model and a Demonstration of its Accuracy Using 129 Galaxies in the Local Universe , 2016, 1609.09073.

[29]  Daniel Foreman-Mackey,et al.  corner.py: Scatterplot matrices in Python , 2016, J. Open Source Softw..

[30]  David W. Hogg,et al.  The Tractor: Probabilistic astronomical source detection and measurement , 2016 .

[31]  Stanford,et al.  THE SPITZER-HETDEX EXPLORATORY LARGE-AREA SURVEY , 2016, 1603.05660.

[32]  W. Brandt,et al.  THE 2 Ms CHANDRA DEEP FIELD-NORTH SURVEY AND THE 250 Ks EXTENDED CHANDRA DEEP FIELD-SOUTH SURVEY: IMPROVED POINT-SOURCE CATALOGS , 2016, 1602.06299.

[33]  H. Rottgering,et al.  The CALYMHA survey: Lyα escape fraction and its dependence on galaxy properties at z = 2.23 , 2016, 1602.02756.

[34]  E. Komatsu,et al.  Bayesian Redshift Classification of Emission-line Galaxies with Photometric Equivalent Widths , 2015, 1510.07043.

[35]  J. Dunlop,et al.  S-CANDELS: THE SPITZER-COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC SURVEY. SURVEY DESIGN, PHOTOMETRY, AND DEEP IRAC SOURCE COUNTS , 2015, 1506.01323.

[36]  M. Hayes Lyman Alpha Emitting Galaxies in the Nearby Universe , 2015, Publications of the Astronomical Society of Australia.

[37]  P. W. Wang,et al.  The VIMOS Ultra Deep Survey: Lyα emission and stellar populations of star-forming galaxies at 2 < z < 2.5 , 2015, 1503.01753.

[38]  Andreas Kelz,et al.  VIRUS: assembly, testing and performance of 33,000 fibres for HETDEX , 2014, Astronomical Telescopes and Instrumentation.

[39]  M. Dijkstra Lyα Emitting Galaxies as a Probe of Reionisation , 2014, Publications of the Astronomical Society of Australia.

[40]  Iap,et al.  Influence of physical galaxy properties on Lyα escape in star-forming galaxies , 2013, 1308.6577.

[41]  M. Dickinson,et al.  Cosmic Star-Formation History , 1996, 1403.0007.

[42]  C. Conroy Modeling the Panchromatic Spectral Energy Distributions of Galaxies , 2013, 1301.7095.

[43]  Daniel Foreman-Mackey,et al.  emcee: The MCMC Hammer , 2012, 1202.3665.

[44]  S. Ravindranath,et al.  CANDELS: THE COSMIC ASSEMBLY NEAR-INFRARED DEEP EXTRAGALACTIC LEGACY SURVEY—THE HUBBLE SPACE TELESCOPE OBSERVATIONS, IMAGING DATA PRODUCTS, AND MOSAICS , 2011, 1105.3753.

[45]  Ulrich Hopp,et al.  HETDEX pilot survey for emission-line galaxies - I. Survey design, performance, and catalog , 2010, 1011.0426.

[46]  H. Ferguson,et al.  The rising star formation histories of distant galaxies and implications for gas accretion with time , 2010, 1007.4554.

[47]  A. Fontana,et al.  Physical and morphological properties of z ~ 3 Lyman break galaxies: dependence on Lyα line emission , 2010, 1002.2068.

[48]  K. Abazajian,et al.  THE SEVENTH DATA RELEASE OF THE SLOAN DIGITAL SKY SURVEY , 2008, 0812.0649.

[49]  A. Fontana,et al.  The physical properties of Lyα emitting galaxies: not just primeval galaxies? , 2008, 0811.1861.

[50]  K. Schawinski,et al.  Lyα-Emitting Galaxies at z = 3.1: L* Progenitors Experiencing Rapid Star Formation , 2007, 0710.2697.

[51]  L. Infante,et al.  Lyα Emission-Line Galaxies at z = 3.1 in the Extended Chandra Deep Field-South , 2007, 0705.3917.

[52]  K. Aoki,et al.  Deficiency of Large Equivalent Width Lyα Emission in Luminous Lyman Break Galaxies at z ~ 5-6? , 2006, astro-ph/0605289.

[53]  James Rhoads,et al.  Luminosity Functions of Lyα Emitters at Redshifts z = 6.5 and z = 5.7: Evidence against Reionization at z ≤ 6.5 , 2004, astro-ph/0407408.

[54]  G. Bruzual,et al.  Stellar population synthesis at the resolution of 2003 , 2003, astro-ph/0309134.

[55]  S. M. Fall,et al.  The Great Observatories Origins Deep Survey: Initial Results from Optical and Near-Infrared Imaging , 2003, astro-ph/0309105.

[56]  G. Chabrier Galactic Stellar and Substellar Initial Mass Function , 2003, astro-ph/0304382.

[57]  M. Pettini,et al.  Rest-Frame Ultraviolet Spectra of z ∼ 3 Lyman Break Galaxies , 2003, astro-ph/0301230.

[58]  H. Ferguson,et al.  The Stellar Populations and Evolution of Lyman Break Galaxies , 2000, astro-ph/0105087.

[59]  Walter A. Siegmund,et al.  The Sloan Digital Sky Survey: Technical Summary , 2000, astro-ph/0006396.

[60]  S. M. Fall,et al.  A Simple Model for the Absorption of Starlight by Dust in Galaxies , 2000, astro-ph/0003128.

[61]  H. Spinrad,et al.  First Results from the Large-Area Lyman Alpha Survey , 1999, astro-ph/0003465.

[62]  A. Kinney,et al.  The Dust Content and Opacity of Actively Star-forming Galaxies , 1999, astro-ph/9911459.

[63]  L. Cowie,et al.  High-z Lyα Emitters. I. A Blank-Field Search for Objects near Redshift z = 3.4 in and around the Hubble Deep Field and the Hawaii Deep Field SSA 22 , 1998, astro-ph/9801003.

[64]  Jordi Miralda-Escude,et al.  Reionization of the Intergalactic Medium and the Damping Wing of the Gunn-Peterson Trough , 1997, astro-ph/9708253.

[65]  E. Bertin,et al.  SExtractor: Software for source extraction , 1996 .

[66]  A. Kinney,et al.  Dust extinction of the stellar continua in starburst galaxies: The Ultraviolet and optical extinction law , 1994 .

[67]  Thomas A. Sebring,et al.  Spectroscopic survey telescope project , 1994, Astronomical Telescopes and Instrumentation.

[68]  D. Neufeld The Escape of Lyman-Alpha Radiation from a Multiphase Interstellar Medium , 1991 .

[69]  J. Mathis,et al.  The relationship between infrared, optical, and ultraviolet extinction , 1989 .

[70]  K. Horne,et al.  AN OPTIMAL EXTRACTION ALGORITHM FOR CCD SPECTROSCOPY. , 1986 .

[71]  R. B. Partridge,et al.  Are Young Galaxies Visible , 1967 .