J/ApJ/892/23ivo://CDS.VizieR/J/ApJ/892/23doi:10.26093/cds/vizier.18920023CDSKessler S.Leroy A.Querejeta M.Murphy E.Rebolledo D.Sandstrom K.,Schinnerer E.Wong T.2022-01-19T08:58:18Z2021-09-13T10:23:34ZCDS support team

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

cds-question@unistra.frgalaxiesvisible-astronomyh-alpha-photometryinfrared-astronomyextinctioninterstellar-mediumWe combine Hubble Space Telescope Paschen {beta} (Pa{beta}) imaging with ground-based, previously published H{alpha} maps to estimate the attenuation affecting H{alpha}, A(H{alpha}), across the nearby, face-on galaxies NGC 5194 and NGC 6946. We estimate A(H{alpha}) in ~2000 independent 2" ~75pc diameter apertures in each galaxy, spanning out to a galactocentric radius of almost 10kpc. In both galaxies, A(H{alpha}) drops with radius, with a bright, high-attenuation inner region, though in detail the profiles differ between the two galaxies. Regions with the highest attenuation-corrected H{alpha} luminosity show the highest attenuation, but the observed H{alpha} luminosity of a region is not a good predictor of attenuation in our data. Consistent with much previous work, the IR-to-H{alpha} color does a good job of predicting A(H{alpha}). We calculate the best-fit empirical coefficients for use combining H{alpha} with 8, 12, 24, 70, or 100{mu}m to correct for attenuation. These agree well with previous work, but we also measure significant scatter around each of these linear relations. The local atomic plus molecular gas column density, N(H), also predicts A(H{alpha}) well. We show that a screen with magnitude ~0.2 times that expected for a Milky Way gas-to-dust value does a reasonable job of explaining A(H{alpha}) as a function of N(H). This could be expected if only ~40% of gas and dust directly overlap regions of H{alpha} emission.2020ApJ...892...23Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/892/23CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVII/233 : The 2MASS Extended sources (IPAC/UMass, 2003-2006)J/MNRAS/423/197 : MIPS photometry for Herschel SAG2 Programs (Bendo+, 2012)J/ApJ/864/136 : Star-forming regions multiwavelength study (Binder+, 2018)J/ApJ/704/842 : VIRUS-P spectroscopy of NGC 5194 (Blanc+, 2009)J/ApJ/633/871 : Positions & photometry of HII knots in M51 (Calzetti+, 2005)J/ApJ/714/1256 : Far-IR star formation rate indicators (Calzetti+, 2010)J/A+A/584/A87 : CALIFA sample SFR calibration (Catalan-Torrecilla+, 2015)J/ApJ/784/3 : The PAWS catalogs of GMCs and islands in M51 (Colombo+, 2014)J/ApJ/808/42 : Abundances of Spirals (CHAOS) II. M51 (Croxall+, 2015)J/MNRAS/388/500 : GHASP: H{alpha} data cubes for 108 galaxies (Epinat+, 2008)J/ApJ/671/333 : Aperture photometry in NGC 5194 (Kennicutt+, 2007)J/ApJ/875/85 : SNRSs opt. search in NGC6946 with WIYN & GMOS (Long+, 2019)J/ApJ/761/97 : Star Formation in Radio Survey (SFRS): 33GHz (Murphy+, 2012)J/ApJS/234/24 : VLA 33GHz obs. of star-forming regions (Murphy+, 2018)J/AJ/156/18 : Binary companions of evolved stars (Price-Whelan+, 2018)J/A+A/625/A19 : 33 GHz continuum map of M51 (Querejeta+, 2019)J/ApJ/656/770 : Mid-IR spectrum of star-forming galaxies (Smith+, 2007)J/AJ/136/2563 : HI Nearby Galaxy Survey, THINGS (Walter+, 2008)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/892/23https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/892/23http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/892/23https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/892/23https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/892/23http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/892/23GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/892/23/table2 (Measured line luminosities and estimated attenuation in NGC 6946)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/892/23/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/892/23/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/892/23/table2?GETtext/xml+votable180.050000true308.848860.16220.005555555555555556Cone search capability for table J/ApJ/892/23/table3 (Measured line luminosities and estimated attenuation in NGC 5194)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/892/23/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/892/23/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/892/23/table3?GETtext/xml+votable180.050000true202.533347.220.0055555555555555566/11026-11027 15592-15593https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/892/23?format=asciiOpticalInfrareddefaultJ/ApJ/892/23/table2Measured line luminosities and estimated attenuation in NGC 6946recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqInternal index identifiermeta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainLHaH{alpha} luminosity; erg/s (1)1e-07Wphys.luminosity;em.line.Halphadoublee_LHaUncertainty in LHa ; erg/s (1)1e-07Wstat.errordoubleLPabPa{beta} luminosity; erg/s (1)1e-07Wphys.luminosity;em.IR.Jdoublee_LPabUncertainty in LPab; erg/s (1)1e-07Wstat.errordoubleAHa[0.0009/9.9] H{alpha} attenuation (1)magphys.absorptionfloate_AHa[0.02/3.7] Uncertainty in AHa (1)magstat.errorfloatHa/24um[0.0003/0.3] H{alpha} to Spitzer 24um band ratiophot.flux;arith.ratio;em.line.HalphadoubleHa/70umH{alpha} to Herschel 70 micron band ratiophot.flux;arith.ratio;em.line.HalphadoubleHa/8um[0.0002/0.09] H{alpha} to Spitzer 8um band ratiophot.flux;arith.ratio;em.line.HalphadoubleHa/12um[0.0007/0.3] H{alpha} to WISE 12um band ratiophot.flux;arith.ratio;em.line.HalphadoubleHa/100um[0.0001/0.06]? H{alpha} to Herschel 100um band ratio (only for NGC 6946)phot.flux;arith.ratio;em.line.HalphadoublenullableJ/ApJ/892/23/table3Measured line luminosities and estimated attenuation in NGC 5194e_LPabUncertainty in LPab; erg/s (1)1e-07Wstat.errordoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeqInternal index identifiermeta.id;meta.mainintRAJ2000Right Ascension in decimal degrees (J2000)degpos.eq.ra;meta.mainDEJ2000Declination in decimal degrees (J2000)degpos.eq.dec;meta.mainLHaH{alpha} luminosity; erg/s (1)1e-07Wphys.luminosity;em.line.Halphadoublee_LHaUncertainty in LHa ; erg/s (1)1e-07Wstat.errordoubleLPabPa{beta} luminosity; erg/s (1)1e-07Wphys.luminosity;em.IR.JdoubleAHa[0.0009/9.9] H{alpha} attenuation (1)magphys.absorptionfloate_AHa[0.02/3.7] Uncertainty in AHa (1)magstat.errorfloatHa/24um[0.0003/0.3] H{alpha} to Spitzer 24um band ratiophot.flux;arith.ratio;em.line.HalphadoubleHa/70umH{alpha} to Herschel 70 micron band ratiophot.flux;arith.ratio;em.line.HalphadoubleHa/8um[0.0002/0.09] H{alpha} to Spitzer 8um band ratiophot.flux;arith.ratio;em.line.HalphadoubleHa/12um[0.0007/0.3] H{alpha} to WISE 12um band ratiophot.flux;arith.ratio;em.line.Halphadouble