J/A+A/567/A88ivo://CDS.VizieR/J/A+A/567/A88doi:10.26093/cds/vizier.35670088CDSStanghellini L.Magrini L.Casasola V.Villaver E.2017-09-22T16:16:34Z2014-07-17T11:34:53ZCDS support team

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

cds-question@unistra.frgalaxiesh-ii-regionschemical-abundancesWe present a new set of weak-line abundances of HII regions in M81, based on Gemini Multi-Object Spectrograph (GMOS) observations. The aim is to derive plasma and abundance analysis for a sizable set of emission-line targets to study the galactic chemical contents in the framework of galactic metallicity gradients. We used the weak-line abundance approach by deriving electron density and temperatures for several HII regions in M81. Gradient analysis is based on oxygen abundances. Together with a set of HII region abundances determined similarly by us with Multi-Mirror Telescope (MMT) spectra, the new data yield to a radial oxygen gradient of -0.088+/-0.013dex/kpc, which is steeper than the metallicity gradient obtained for planetary nebulae (-0.044+/-0.007dex/kpc). This result could be interpreted as gradient evolution with time: Models of galactic evolution with inside-out disk formation associated to pre-enriched gas infall would produce such difference of gradients, although stellar migration effects would also induce a difference in the metallicity gradients between the old and young populations.2014A&A...567A..88Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/567/A88CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/A+A/379/90 : Candidate Planetary Nebulae in M81 (Magrini+, 2001)J/AJ/126/1286 : H{alpha}+[NII] observations of M81 HII regions (Lin+, 2003)J/A+A/521/A3 : Abundances in HII regions and PNe of M81 (Stanghellini+, 2010)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/567/A88https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/567/A88http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/567/A88https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/567/A88https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/567/A88http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/567/A88GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/567/A88/table2 (Regions with spectroscopy)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/567/A88/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/567/A88/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/567/A88/table2?GETtext/xml+votable180.050000true148.7525938969.218063060.0055555555555555566/7606https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/567/A88?format=asciiOpticaldefaultJ/A+A/567/A88/table2Regions with spectroscopyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion name (field 1: 1-27F1; field 2: 1-29F2)meta.id;meta.maincharprimaryn_Region[b-g] Note (1)meta.notecharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainAliasPossible earlier identification (2)meta.idcharNaNumber of derived abundance parameters (table4)meta.ref.urlintnullableNfNumber of observed fluxes (table3)meta.ref.urlintnullableSp[Y/N] spectrum used (3)meta.codecharwl[YUN] Flag on weak-line abundances (4)meta.codecharcbeta[0/2.5]? H{beta} logarithmic extinctionphys.absorptionfloatnullablee_cbeta? rms uncertainty on cbetastat.errorfloatnullableSimbadSimbad column added by the CDSmeta.ref.urlcharJ/A+A/567/A88/table3Observed fluxes and line intensitiesIonIonphys.atmol.ionStagecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegionmeta.id;meta.maincharlambdaWavelength {lambda}0.1nmem.wlintFlux? Flux (erg/cm^2^/s)mW.m**-2phot.fluxfloatnullablee_Flux? rms uncertainty in FluxmW.m**-2stat.error;phot.fluxfloatnullableInt? Intensity (erg/cm^2^/s)mW.m**-2spect.line.intensityfloatnullableJ/A+A/567/A88/table4Plasma analysis and abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionRegion namemeta.id;meta.maincharParamParameter name (1)meta.id;stat.paramcharValue? Parameter valuestat.paramdoublenullablen_Value[NA] NA for not analysedmeta.notechar