J/ApJ/939/44ivo://CDS.VizieR/J/ApJ/939/44doi:10.26093/cds/vizier.19390044CDSRogers N.S.J.Skillman E.D.Pogge R.W.Berg D.A.Croxall K.V.,Bartlett J.Arellano-Cordova K.Z.Moustakas J.2025-02-18T20:14:22Z2024-11-18T15:22:10ZCDS support team

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

cds-question@unistra.frchemical-abundancesgalaxiesh-ii-regionsvisible-astronomyspectroscopyinfrared-astronomyThe dispersion in chemical abundances provides a very strong constraint on the processes that drive the chemical enrichment of galaxies. Due to its proximity, the spiral galaxy M33 has been the focus of numerous chemical abundance surveys to study the chemical enrichment and dispersion in abundances over large spatial scales. The CHemical Abundances Of Spirals project has observed ~100 HII regions in M33 with the Large Binocular Telescope (LBT), producing the largest homogeneous sample of electron temperatures (Te) and direct abundances in this galaxy. Our LBT observations produce a robust oxygen abundance gradient of -0.037+/-0.007dex/kpc and indicate a relatively small (0.043+/-0.015dex) intrinsic dispersion in oxygen abundance relative to this gradient. The dispersions in N/H and N/O are similarly small, and the abundances of Ne, S, Cl, and Ar relative to O are consistent with the solar ratio as expected for {alpha}-process or {alpha}-process-dependent elements. Taken together, the ISM in M33 is chemically well-mixed and homogeneously enriched from inside out, with no evidence of significant abundance variations at a given radius in the galaxy. Our results are compared to those of the numerous studies in the literature, and we discuss possible contaminating sources that can inflate abundance dispersion measurements. Importantly, if abundances are derived from a single Te measurement and Te-Te relationships are relied on for inferring the temperature in the unmeasured ionization zone, this can lead to systematic biases that increase the measured dispersion up to 0.11 dex.2022ApJ...939...44Rhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/939/44CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVI/64 : Recombination line intensities for hydrogenic ions (Storey+ 1995)VI/141 : Nebular [OIII] collision strengths - SSB (Storey+, 2014)J/A+A/448/955 : Abundances of emission galaxies in SDSS-DR3 (Izotov+, 2006)J/AJ/131/2478 : M31 and M33 UBVRI photometry (Massey+, 2006)J/AJ/134/2474 : Ha emission-line stars in 7 dwarfs galaxies (Massey+, 2007)J/ApJ/675/1213 : Abundances in M33 HII regions (Rosolowsky+, 2008)J/ApJ/700/654 : Keck sp. of extragalactic HII regions (Esteban+ 2009)J/A+A/500/1253 : Electron-impact excitation of ArIII (Munoz Burgos+, 2009)J/A+A/512/A63 : Abundances of M33 HII regions (Magrini+, 2010)J/ApJS/190/233 : Sp. and abundances of SINGS galaxies (Moustakas+, 2010)J/ApJS/188/32 : Breit-Pauli transition probabilities for SII (Tayal+, 2010)J/ApJ/790/48 : Variable stars in M31 & M33. II. LBVs (Humphreys+, 2014)J/ApJ/808/174 : FeII radiative transition rates (Bautista+, 2015)J/ApJ/806/16 : CHemical Abund. of Spirals (CHAOS). I. NGC628 (Berg+, 2015)J/ApJ/808/42 : CHemical Abund. of Spirals (CHAOS) II. M51 (Croxall+, 2015)J/MNRAS/455/2627 : Oxygen abundance gradient in M81 (Arellano-Cordova+, 2016)J/ApJ/830/4 : HII region abundances in NGC 5457 (M101) (Croxall+, 2016)J/ApJ/842/97 : Spectroscopic obs. of 413 HII regions in M33 (Lin+, 2017)J/ApJS/244/24 : A z=0 Multiwavelength Galaxy Synthesis. I. (Leroy+, 2019)J/A+A/623/A155 : SII, ClII, ArIV energy levels & transitions (Rynkun+, 2019)J/MNRAS/497/672 : Abundances in HII regions (Arellano-Cordova+, 2020)J/ApJ/893/96 : CHAOS IV: NGC3184 LBT obs. & 3 other gal. (Berg+, 2020)J/ApJS/257/43 : PHANGS-ALMA: CO(2-1) imaging of galaxies (Leroy+, 2021)J/ApJ/915/21 : CHAOS. VI. Direct abundances in NGC 2403 (Rogers+, 2021)J/ApJ/925/76 : M33 with LAMOST sp. I. PNe & HII regions (Alexeeva+, 2022)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/939/44https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/939/44http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/939/44https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/939/44https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/939/44http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/939/44GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/939/44/table2 (M33 LBT/MODS observations)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/939/44/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/939/44/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/939/44/table2?GETtext/xml+votable180.050000true23.4630.6653810.0055555555555555566/2154-2155 2241https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/939/44?format=asciiOpticalInfrareddefaultJ/ApJ/939/44/table2M33 LBT/MODS observationsRgc[0.13/7.5] Distance from galactic centerkpcpos.distancefloatRgc/Re[0.05/3.3] Distance from galactic center over effective radiuspos.distance;arith.ratiofloatRefLiterature reference code(s) (2)meta.bibcharPMeasurements available in Table A3 for this region; column added by CDSmeta.codecharEmLDisplay the emission line intensities (link to Table A2)meta.ref.urlcharParamDisplay the parameter results (link to Table A3)meta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionHII region identifier (1)meta.id;meta.maincharprimaryRAJ2000[1] Hour of Right Ascension (J2000)pos.eq.ra;meta.mainDEJ2000[30] Degree of Declination (J2000)pos.eq.dec;meta.mainJ/ApJ/939/44/tablea2M33 emission line intensitiesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionHII region identifiermeta.id;meta.maincharParamParameter description (1)meta.notecharValue[0/2031]? Parameter value (2)stat.paramdoublenullablee_Value[0/42]? Uncertainty in Valuestat.error;stat.valuefloatnullablelowValue[0/4.3]? Lower uncertainty in Value (3)stat.errorfloatnullableJ/ApJ/939/44/tablea3M33 temperatures, densities, and abundancesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRegionHII region identifiermeta.id;meta.maincharParamParameter description (1)meta.noteValue[-7.36/28100]? Parameter valuestat.paramdoublenullableu_Value[:] Uncertainty flag on Value (2)meta.code.error;stat.valuecharE_Value[0.01/4900]? Upper uncertainty in Valuestat.error;stat.maxfloatnullablee_Value[0.02/4900]? Lower uncertainty in Valuestat.error;stat.valuefloatnullable