The Lyman Alpha Reference Sample. XVI. Global 21cm HI properties of Lyman-$\alpha$ emitting galaxies

Abstract

The Lyman-$\alpha$ (Lya) line of hydrogen is a well-known tracer of galaxies at high-z. However, the connection between Lya observables and galaxy properties has not fully been established, limiting the use of the line to probe the physics of galaxies. Here, we derive global neutral hydrogen gas (HI) properties of nearby Lya-emitting galaxies to assess the impact of HI on the Lya output of galaxies. We observed 21cm line emission using the VLA in D-array configuration (~55" resolution, ~38 kpc) for 37 star-forming galaxies with available Lya imaging from the Lyman Alpha Reference Samples (LARS and eLARS). We detect 21cm emission for 33/37 galaxies observed. We find no significant correlation of global HI properties with Lya luminosity, escape fraction or equivalent width derived with HST photometry. Additionally, both Lya-emitters and weak or non-emitters are distributed evenly along the HI parameter space of optically-selected z=0 galaxies. Around 74% of the sample is undergoing galaxy interaction, this fraction is higher for Lya-emitters (83% for galaxies with EW$\ge$20Å) than for non or weak emitters (70%). Nevertheless, galaxies identified as interacting have Lya and HI properties statistically consistent with those of non-interacting galaxies. Our results show that global HI properties (on scales > 30kpc) have little direct impact on the Lya output from galaxies. Instead, HI likely regulates Lya emission on small scales: statistical comparisons of Lya and high angular resolution 21cm observations are required to fully assess the role of HI in Lya radiative transfer. While our study indicates that galaxy mergers could play a role in the emission of Lya photons in the local universe, especially for galaxies with high HI fractions, the line-of-sight through which a system is observed ultimately determines Lya observables.

arXiv comment15+35 pages, 5+33 figures, Accepted for publication in A&A

References in corpus (56)

• The physical properties of star forming galaxies in the low redshift universe
• Overview of the DESI Legacy Imaging Surveys
• UV Star Formation Rates in the Local Universe
• A Highly Consistent Framework for the Evolution of the Star-Forming "Main Sequence" from z~0-6
• Rest-Frame Ultraviolet Spectra of z~3 Lyman Break Galaxies
• CASA, the Common Astronomy Software Applications for Radio Astronomy
• The Arecibo Legacy Fast ALFA Survey: The ALFALFA Extragalactic HI Source Catalog
• 3D Lyman-alpha radiation transfer. I. Understanding Lyman-alpha line profile morphologies
• 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
• GALEX-SDSS-WISE Legacy Catalog (GSWLC): Star Formation Rates, Stellar Masses and Dust Attenuations of 700,000 Low-redshift Galaxies
• The Keck Lyman Continuum Spectroscopic Survey (KLCS): The Emergent Ionizing Spectrum of Galaxies at $z\sim 3$
• Lyman Alpha Emitting Galaxies as a Probe of Reionization
• SoFiA: a flexible source finder for 3D spectral line data
• Ly$\alpha$ emission from Green Peas: the role of circumgalactic gas density, covering, and kinematics
• Observations of the Lyman-$\alpha$ Universe
• SoFiA 2 -- An automated, parallel HI source finding pipeline for the WALLABY survey
• The Lyman alpha Reference Sample: II. HST imaging results, integrated properties and trends
• The Ultraviolet Spectrum of the Gravitationally Lensed Galaxy `The Cosmic Horseshoe': A Close-up of a Star-forming Galaxy at z = 2
• Lyman alpha emission in starbursts: implications for galaxies at high redshift
• The Connection Between Reddening, Gas Covering Fraction, and the Escape of Ionizing Radiation at High Redshift
• Models for Dusty Lyman alpha Emitters at High Redshift
• The Lyman-alpha Reference Sample: I. Survey outline and first results for Markarian 259
• Highest Redshift Image of Neutral Hydrogen in Emission: A CHILES Detection of a Starbursting Galaxy at z=0.376
• New Insights on Ly-alpha and Lyman Continuum Radiative Transfer in the Greenest Peas
• The Lyman Alpha Reference Sample: V. The impact of neutral ISM kinematics and geometry on Lyman Alpha escape
• The origin of the escape of Lyman alpha and ionizing photons in Lyman Continuum Emitters
• AUTO-MULTITHRESH: A General Purpose Automasking Algorithm
• Neutral gas properties of Lyman continuum emitting galaxies: column densities and covering fractions from UV absorption lines
• HI 21-centimetre emission from an ensemble of galaxies at an average redshift of one
• Empirical Estimate of Lyman-alpha Escape Fraction in a Statistical Sample of Lyman-alpha Emitters
• Lya escape from z~0.03 star-forming galaxies: the dominant role of outflows
• The Effects of Stellar Population and Gas Covering Fraction on the Emergent Lyman Alpha Emission of High-Redshift Galaxies
• The LyAlpha Line Profiles of Ultraluminous Infrared Galaxies: Fast Winds and Lyman Continuum Leakage
• HST/ACS Lyman alpha imaging of the nearby starburst ESO338-IG04
• The ALFALFA-SDSS Galaxy Catalog
• HST Emission Line Galaxies at z ~ 2: Comparing Physical Properties of Lyman Alpha and Optical Emission Line Selected Galaxies
• Cold gas and star formation in a merging galaxy sequence
• New criteria for the selection of galaxy close pairs from cosmological simulations: evolution of the major and minor merger fraction in MUSE deep fields
• Deciphering Lyman-$\alpha$ Emission Deep into the Epoch of Reionisation
• HETDEX Public Source Catalog 1: 220K Sources Including Over 50K Lyman Alpha Emitters from an Untargeted Wide-area Spectroscopic Survey
• The Lyman alpha reference sample: IV. Morphology at low and high redshift
• The Lyman Alpha Reference Sample: III. Properties of the Neutral ISM from GBT and VLA Observations
• First release of Apertif imaging survey data
• Extended Tidal Structure In Two Lyman Alpha-Emitting Starburst Galaxies
• Lyman break galaxy close and interacting pairs at z ~ 3
• The source of leaking ionizing photons from Haro11 -- Clues from HST/COS spectroscopy of knots A, B and C
• Spectral Shapes of the Lya Emission from Galaxies. II. the influence of stellar properties and nebular conditions on the emergent Lya profiles
• Quantified HI Morphology IV: The Merger Fraction and Rate in WHISP
• The Atomic Gas Mass of Green Pea Galaxies
• Towards the first detection of strongly lensed HI emission
• The Lyman Alpha Spectral Database (LASD)
• A Green Pea starburst arising from a galaxy-galaxy merger
• The Lyman $\alpha$ Reference Sample XIV: Lyman $\alpha$ imaging of 45 low redshift star-forming galaxies and inferences on global emission
• HI Imaging of a Blueberry Galaxy Suggests a Merger Origin
• The Lyman Alpha Reference Sample IX: Revelations from deep surface photometry
• The Lyman Alpha Reference Sample XV. Relating Ionised Gas Kinematics with Lyman-$\alpha$ observables

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• The Importance of Dust Distribution in Ionizing-photon Escape: NIRCam and MIRI Imaging of a Lyman Continuum-emitting Galaxy at z ~ 3.8
• The Ly$\alpha$ and Continuum Origins Survey. III. Investigating the Link between Galaxy Morphology, Merger Properties and LyC Escape