J/A+A/693/A253ivo://CDS.VizieR/J/A+A/693/A253doi:10.26093/cds/vizier.36930253CDSLe Reste A.Hayes M.J.Cannon J.M.Melinder J.Runnholm A.,Rivera-Thorsen T. E.Ostlin G.Adamo A.Herenz E.C.Schaerer D.,Scarlata C.Kunth D.2025-09-22T20:01:20Z2025-05-30T14:58:31ZCDS support team

CDS, Observatoire de Strasbourg, 11 rue de l'Universite, F-67000 Strasbourg, France

cds-question@unistra.frradio-galaxiesh-i-line-emissionultraviolet-astronomyThe Lyman-alpha (Ly{alpha}) line of hydrogen is a well-known tracer of galaxies at high redshift. However, the connection between Ly{alpha} observables and galaxy properties has not been fully established, limiting the use of the line to probe the physics of galaxies. Here, we derive the global neutral hydrogen gas (HI) properties of nearby Ly{alpha}-emitting galaxies to assess the impact of neutral gas on the Ly{alpha} output of galaxies. We observed the 21cm line emission using the Karl G. Jansky Very Large Array in D-array configuration (~55" resolution, ~38kpc) for 37 star-forming galaxies with available Hubble Space Telescope (HST) Ly{alpha} imaging from the Lyman Alpha Reference Samples. We detected 21 cm emission for 33 out of the 37 galaxies observed. We found no significant correlation of global HI properties (including HI mass, column density, gas fraction, depletion time, line width, or velocity shift between HI and Ly{alpha}), with the Ly{alpha} luminosity, escape fractions, or equivalent widths (EW) derived with HST photometry. Additionally, both Ly{alpha}-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 Ly{alpha}-emitters (83% for galaxies with EW>=20{AA}) than for weak or non-emitters (70%). Nevertheless, galaxies identified as interacting have Ly{alpha} 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 Ly{alpha} output from galaxies. Instead, HI likely regulates Ly{alpha} emission on small scales: statistical comparisons of Ly{alpha} and high angular resolution 21cm observations are required to fully assess the role of HI in Ly{alpha} radiative transfer. While our study indicates that major and minor galaxy mergers could play a role in the emission of Ly{alpha} photons in the local Universe, especially for galaxies with high HI fractions, the line of sight that a system is observed through ultimately determines the Ly{alpha} observables.2025A&A...693A.253Lhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/693/A253CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/644/A10 : LARS XI. Turbulence Driven Lyman Alpha Escape (Puschnig+, 2020)J/ApJS/266/15 : The Ly{alpha} Reference Sample (LARS). XIV. (Melinder+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/693/A253https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/693/A253http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/693/A253https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/693/A253https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/693/A253http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/693/A253GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/693/A253/tablea2 (General galaxy and Ly{alpha} properties)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/693/A253/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/693/A253/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/693/A253/tablea2?GETtext/xml+votable180.050000true202.183443.930530.0055555555555555566/5026 5814 6013 6110 6115 6128 6141 7259 7272 7294 7441 7452 7472 7509 7523 9923 10144 10192 10220 10393 10404 11009 11115 11133 11183 11220 11386 11500 11505 11512 11778 11782 11824 11826 11855 11908 11968 18302 26095 26359https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/693/A253?format=asciiUVRadiodefaultJ/A+A/693/A253/table1Merger identification flagsint[0/1] Interaction flag (1=int, 0=no int) (int)meta.codeintrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSample Identifier used in this work, LRASNN or eLARSNN (ID)meta.id;meta.maincharclosepair[0/1] Close pair interaction flag (closepair)meta.codeintintMorphOpt[0/1] Optical morphology interaction flag (int_morph_opt)meta.codeintintMorphHI[0/1]? HI morphology interaction flag (int_morph_hi)meta.codeintnullableintHaKin[0/1] H{alpha} kinematics interaction flag (int_ha_kin)meta.codeintJ/A+A/693/A253/tablea1VLA observation parametersrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSample Identifier used in this work (ID)meta.id;meta.maincharTobs? Integration time (t_obs)htime.epochfloatnullablepflag? Percentage of flagged visibilities (p_flag)meta.codefloatnullablebpcalBandpass calibrator (bp_cal)instr.calibcharphcalPhase calibrator (ph_cal)instr.calibcharbmin? Beam minor axis (bmin)arcsecphys.angSize;srcfloatnullablebmaj? Beam major axis (bmaj)arcsecphys.angSize;srcfloatnullablePA[]? Beam position angle (pa)degpos.posAng;instr.beamfloatnullablerms? VLA cube RMS (rms)mJystat.stdevfloatnullableJ/A+A/693/A253/tablea2General galaxy and Ly{alpha} propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSample Identifier used in this work (ID)meta.id;meta.maincharRAJ2000Right Ascension J2000 (RA)degpos.eq.ra;meta.mainDEJ2000Declination J2000 (DEC)degpos.eq.dec;meta.mainzRedshift (z)src.redshiftdoubleDLuminosity distance (D)Mpcpos.distancedoubleMGSWLCStellar mass (from GSWLC) (M_GSWLC)solMassphys.massdoublee_MGSWLCStellar mass error (from GSWLC) (M_GSWLCe)solMassstat.errordoubleSFRGSWLCStar formation rate (from GSWLC) (SFR_GSWLC)solMass/yrphys.SFRdoublee_SFRGSWLCStar formation rate error (from GSWLC) (SFR_GSWLCe)solMass/yrstat.errordoubleDvLyared? Ly{alpha} red peak offset velocity (from systemic) (Dv_Lya_red)km/sspect.dopplerVelocdoublenullableb_DvLyaredLy{alpha} red peak offset velocity lower bound error (Dv_Lya_redl)km/sstat.error;phys.veloc;instr.offsetdoubleB_DvLyaredLy{alpha} red peak offset velocity upper bound error (Dv_Lya_redu)km/sstat.error;phys.veloc;instr.offsetdoubleNote[a] a = GSWLC values predicted from fit to SDSS data (note)meta.notecharJ/A+A/693/A253/tablea321cm line propertiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDSample Identifier used in this work (ID)meta.id;meta.maincharvHIb? 21cm line centroid velocity (beam extraction) (v_HI_b)km/sphys.velocdoublenullablee_vHIb? 21cm line centroid velocity error (beam extraction) (v_HI_be)km/sstat.errordoublenullablezHIb? 21cm line centroid redshift (beam extraction) (z_HI_b)src.redshift;pos.heliocentricdoublenullablee_zHIb? 21cm line centroid redshift error (beam extraction) (z_HI_be)stat.errordoublenullableSHIb? 21cm line flux density (beam extraction) (S_HI_b)Jy.km/sphot.flux.density;em.radio.750-1500MHzdoublenullablee_SHIb? 21cm line flux density error (beam extraction) (S_HI_be)Jy.km/sstat.errordoublenullableMHIb? HI mass (beam extraction) (M_HI_b)solMassphys.massdoublenullablee_MHIb? HI mass error (beam extraction) (M_HI_be)solMassstat.errordoublenullableNHIb? HI column density (beam extraction) (N_HI_b)cm**-2phys.columnDensitydoublenullablee_NHIb? HI column density error (beam extraction) (N_HI_be)cm**-2stat.errordoublenullableW50HIb? HI line width (beam extraction) (W50_HI_b)km/sspect.line.widthdoublenullablevHIt? 21cm line centroid velocity (total extraction) (v_HI_t)km/sphys.velocdoublenullablee_vHIt? 21cm line centroid velocity error (total extraction) (v_HI_te)km/sstat.errordoublenullablezHIt? 21cm line centroid redshift (total extraction) (z_HI_t)src.redshift;pos.heliocentricdoublenullablee_zHIt? 21cm line centroid redshift error (total extraction) (z_HI_te)stat.errordoublenullableSHIt? 21cm line flux density (total extraction) (S_HI_t)Jy.km/sphot.flux.density;em.radio.750-1500MHzdoublenullablee_SHIt? 21cm line flux density error (total extraction) (S_HI_te)Jy.km/sstat.errordoublenullableMHIt? HI mass (total extraction) (M_HI_t)solMassphys.massdoublenullablee_MHIt? HI mass error (total extraction) (M_HI_te)solMassstat.errordoublenullableNHIt? HI column density (total extraction) (N_HI_t)cm**-2phys.columnDensitydoublenullablee_NHIt? HI column density error (total extraction) (N_HI_te)cm**-2stat.errordoublenullableW50HIt? HI line width (total extraction) (W50_HI_t)km/sspect.line.widthdoublenullable