Spectral Shapes of the Lya Emission from Galaxies. II. the influence of stellar properties and nebular conditions on the emergent Lya profiles

Abstract

We demonstrate how the stellar and nebular conditions in star-forming galaxies modulate the emission and spectral profile of HI Lya emission line. We examine the net Lya output, kinematics, and in particular emission of blue-shifted Lya radiation, using spectroscopy from with the Cosmic Origins Spectrograph on HST, giving a sample of 87 galaxies at redshift z=0.05-0.44. We contrast the Lya spectral measurements with properties of the ionized gas (from optical spectra) and stars (from stellar modeling). We demonstrate correlations of unprecedented strength between the Lya escape fraction (and equivalent width) and the ionization parameter (p~10^-15). The relative contribution of blue-shifted emission to the total Lya also increases from ~0 to ~40% over the range of O_32 ratios (p~10^-6). We also find particularly strong correlations with estimators of stellar age and nebular abundance, and weaker correlations regarding thermodynamic variables. Low ionization stage absorption lines suggest the Lya emission and line profile are predominantly governed by the column of absorbing gas near zero velocity. Simultaneous multi-parametric analysis over many variables shows we can predict 80% of the variance on Lya luminosity, and ~50% on the EW. We determine the most crucial predictive variables, finding that for tracers of the ionization state and Hb luminosity dominate the luminosity prediction whereas the Lya EW is best predicted by Hb EW and the Ha/Hb ratio. We discuss our results with reference to high redshift observations, focussing upon the use of Lya to probe the nebular conditions in high-z galaxies and cosmic reionization.

arXiv commentAccepted by MNRAS. 27 pages and 19 figures. ~90 online-only Figures are available here: https://ttt.astro.su.se/~mhaye/t/onlineonly_resub.pdf

References in corpus (97)

• The chemical composition of the Sun
• Measuring Reddening with SDSS Stellar Spectra and Recalibrating SFD
• The Dust Content and Opacity of Actively Star-Forming Galaxies
• Starburst99: Synthesis Models for Galaxies with Active Star Formation
• The Host Galaxies of AGN
• The Origin of the Mass--Metallicity Relation: Insights from 53,000 Star-Forming Galaxies in the SDSS
• Star Formation in the Milky Way and Nearby Galaxies
• Theoretical Modeling of Starburst Galaxies
• [O III]/[N II] as an Abundance Indicator at High Redshift
• A Simple Model for the Absorption of Starlight by Dust in Galaxies
• The Sixteenth Data Release of the Sloan Digital Sky Surveys: First Release from the APOGEE-2 Southern Survey and Full Release of eBOSS Spectra
• Rest-Frame Ultraviolet Spectra of z~3 Lyman Break Galaxies
• Using Strong Lines to Estimate Abundances in Extragalactic HII Regions and Starburst Galaxies
• The Mass-Metallicity Relation at z~2
• AMAZE. I. The evolution of the mass-metallicity relation at z>3
• PyNeb: a new tool for analyzing emission lines. I. Code description and validation of results
• The O3N2 and N2 abundance indicators revisited: improved calibrations based on CALIFA and Te-based literature data
• 3D Lyman-alpha radiation transfer. I. Understanding Lyman-alpha line profile morphologies
• Starbursts and Star Clusters in the Ultraviolet
• Optimization of Starburst99 for Intermediate-Age and Old Stellar Populations
• 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
• The Effects of Stellar Rotation. II. A Comprehensive Set of Starburst99 Models
• Reconciling the Stellar and Nebular Spectra of High Redshift Galaxies
• The End of the Reionization Epoch Probed by Ly-alpha Emitters at z=6.5 in the Subaru Deep Field
• The Mass-Metallicity and the Fundamental Metallicity Relation revisited on a fully Te-based abundance scale for galaxies
• Direct Oxygen Abundances for Low Luminosity LVL Galaxies
• Lyman-alpha and CIII] Emission in z=7-9 Galaxies: Accelerated Reionization Around Luminous Star Forming Systems?
• Ionization State of Inter-Stellar Medium in Galaxies: Evolution, SFR-M_star-Z Dependence, and Ionizing Photon Escape
• The Systematic Properties of the Warm Phase of Starburst-Driven Galactic Winds
• Using Lyman-alpha to detect galaxies that leak Lyman continuum
• Ly Alpha Emitters at z=5.7 in the Subaru Deep Field
• Ly$\alpha$ emission from Green Peas: the role of circumgalactic gas density, covering, and kinematics
• Lyman-alpha spectral properties of five newly discovered Lyman continuum emitters
• The Star Formation Main Sequence in the Hubble Space Telescope Frontier Fields
• Spectroscopic Confirmation of Three Redshift 5.7 Lyman-alpha Emitters from the Large Area Lyman Alpha Survey
• Observations of the Lyman-$\alpha$ Universe
• Escape of about five per cent of Lyman-alpha photons from high-redshift star-forming galaxies
• The Mass and Momentum Outflow Rates of Photoionized Galactic Outflows
• Lyman continuum leakage from low-mass galaxies with Mstar < 1.E8 Msun
• The Lyman alpha Reference Sample: II. HST imaging results, integrated properties and trends
• Constraining the metallicities, ages, star formation histories, and ionizing continua of extragalactic massive star populations
• Lyman alpha emission in starbursts: implications for galaxies at high redshift
• Mapping dust through emission and absorption in nearby galaxies
• The MUSE-Wide Survey: Survey Description and First Data Release
• The Lyman Alpha Reference Sample: V. The impact of neutral ISM kinematics and geometry on Lyman Alpha escape
• New Insights on Ly-alpha and Lyman Continuum Radiative Transfer in the Greenest Peas
• Empirical strong-line oxygen abundance calibrations from galaxies with electron temperature measurements
• The origin of the escape of Lyman alpha and ionizing photons in Lyman Continuum Emitters
• Lyman Radiation Hydrodynamics of Turbulent H II Regions in Molecular Clouds: A Physical Origin of LyC Leakage and the Associated Ly$\alpha$ Spectra
• The MUSE-Wide Survey: A first catalogue of 831 emission line galaxies
• The Implications of Extreme Outflows from Extreme Starbursts
• The effect of dust geometry on the Lyman-alpha output of galaxies
• The MUSE Hubble Ultra Deep Field Survey VI: The Faint-End of the Lya Luminosity Function at 2.91 < z < 6.64 and Implications for Reionisation
• Neutral gas properties of Lyman continuum emitting galaxies: column densities and covering fractions from UV absorption lines
• Physical Properties of Spectroscopically-Confirmed Galaxies at z >= 6. II. Morphology of the Rest-Frame UV Continuum and Lyman-alpha Emission
• Beacons into the Cosmic Dark Ages: Boosted transmission of Ly$\alpha$ from UV bright galaxies at $z\gtrsim 7$
• Lyman alpha Emitting Galaxies in the Nearby Universe
• Diverse properties of Ly-alpha emission in low-redshift compact star-forming galaxies with extremely high [OIII]/[OII] ratios
• Empirical Estimate of Lyman-alpha Escape Fraction in a Statistical Sample of Lyman-alpha Emitters
• Linking Ly-alpha and Low-Ionization Transitions at Low Optical Depth
• [ArIII]/[OIII] and [SIII]/[OIII]: well-behaved oxygen abundance indicators for HII regions and star forming galaxies
• The X-SHOOTER Lyman-$\alpha$ survey at z=2 (XLS-z2) I: What makes a galaxy a Lyman-$\alpha$ emitter?
• LBT observations of compact star-forming galaxies with extremely high [OIII]/[OII] flux ratios: HeI emission-line ratios as diagnostics of Lyman continuum leakage
• High-mass X-ray binaries in nearby metal-poor galaxies: on the contribution to nebular HeII emission
• A new technique for finding galaxies leaking Lyman-continuum radiation: [SII]-deficiency
• A Semi-Analytical Line Transfer (SALT) model to interpret the spectra of galaxy outflows
• HST/ACS Lyman alpha imaging of the nearby starburst ESO338-IG04
• The MUSE-Wide Survey: A determination of the Lyman $\alpha$ emitter luminosity function at $3<z<6$
• (Re)Solving Reionization with Lyα: How Bright Lyα Emitters account for the $z\approx 2-8$ Cosmic Ionizing Background
• The extended HeII$\lambda$4686 emission in the extremely metal-poor galaxy SBS0335-052E seen with MUSE
• Kinematics and Optical Depth in the Green Peas: Suppressed Superwinds in Candidate LyC Emitters
• The unusual NIV]-emitter galaxy GDS J033218.92-275302.7: star formation or AGN-driven winds from a massive galaxy at z=5.56
• [NeIII]/[OII] as an Ionization Parameter Diagnostic in Star-Forming Galaxies
• Modeling $237$ Lyman-$\alpha$ spectra of the MUSE-Wide survey
• On the influence of physical galaxy properties on Lyman-alpha escape in star-forming galaxies
• The Low-redshift Lyman-continuum Survey: [S II]-deficiency and the leakage of ionizing radiation
• Spectral shapes of the Lyman-alpha emission from galaxies: I. blueshifted emission and intrinsic invariance with redshift
• Spectral variations of Lyman-alpha emission within strongly lensed sources observed with MUSE
• The VANDELS survey: the role of ISM and galaxy physical properties on the escape of Lyα emission in z $\sim$ 3.5 star-forming galaxies
• Tracing Lyman-alpha and Lyman Continuum Escape in Galaxies with Mg II Emission
• Constraining Lyman-alpha spatial offsets at $3<z<5.5$ from VANDELS slit spectroscopy
• Deciphering Lyman $\alpha$ blob 1 with deep MUSE observations
• Lyman Alpha Reference Sample: X. Predicting Lyman alpha output from starforming galaxies using multivariate regression
• Lyman continuum leaking galaxies - Search strategies and local candidates
• Stars and gas in the most metal-poor galaxies I: COS and MUSE observations of SBS 0335-052E
• A Semi-Analytical Line Transfer (SALT) Model II: the effects of a Bi-Conical geometry
• Direct Constraints on the Extremely Metal-Poor Massive Stars Underlying Nebular C IV Emission from Ultra-Deep HST/COS Ultraviolet Spectroscopy
• The properties of the brightest Lyman alpha emitters at z~5.7
• The Effect of Bi-conical Outflows on Ly$\alpha$ Escape From Green Peas
• Haro 11 -- Untying the knots of the nuclear starburst
• No correlation of the Lyman continuum escape fraction with spectral hardness
• Diffuse Far-UV Line Emission from the Low-Redshift Lyman Break Galaxy Analog KISSR242
• A Correlation Between Lyα Spectral Line Profile and Rest-Frame UV Morphology
• The Lyman Alpha Spectral Database (LASD)
• Lyman-$\alpha$ photons through rotating outflows
• The Utility of Lyman-alpha Emission Lines as a Probe of Interactions between High Redshift Galaxies and their Environments
• Accelerating Galaxy Winds During the Big Bang of Starbursts

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• On the sizes of ionized bubbles around the highest redshift galaxies. Spectral shapes of the Lyman-alpha emission from galaxies
• Early Results from GLASS-JWST XXII: Rest frame UV-optical spectral properties of Lyman-alpha emitting galaxies at 3 $<$ z $<$ 6
• Early Results from GLASS-JWST XXIII: The transmission of Lyman-alpha from UV-faint z ~ 3-6 galaxies
• Constraints on the $z\sim 6-13$ intergalactic medium from JWST spectroscopy of Lyman-alpha damping wings in galaxies
• On the evolution of the size of Lyman alpha halos across cosmic time: no change in the circumgalactic gas distribution when probed by line emission
• Mapping reionization bubbles in the JWST era I: empirical edge detection with Lyman alpha emission from galaxies
• Mapping reionization bubbles in the JWST era II: inferring the position and characteristic size of individual bubbles
• A MUSE/VLT spatially resolved study of the emission structure of Green Pea galaxies
• Ionizing Radiation Escape from Low-Redshift Galaxies and Its Connection to Cosmic Reionization
• The Intrinsic Distribution of Lyman-$\alpha$ Halos
• The Lyman Alpha Reference Sample. XVI. Global 21cm HI properties of Lyman-$\alpha$ emitting galaxies
• zELDA II: reconstruction of galactic Lyman-alpha spectra attenuated by the intergalactic medium using neural networks