J/A+A/694/A61ivo://CDS.VizieR/J/A+A/694/A61doi:10.26093/cds/vizier.36940061CDSGavilan MDiaz A.I.Zamora S.2025-03-03T20:02:04Z2025-01-31T10:26:37ZCDS support team

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

cds-question@unistra.frgalaxiesh-ii-regionschemical-abundancesvisible-astronomyThe main objective of this work is to derive the distribution of the metal content of HII galaxies using sulphur as an abundance tracer. This increases the metallicity range that can safely be reached. We selected a sample of emission-line galaxies that we extracted from the SDSS-DR16. These objects have a redshift of z<=0.04 so that the [SIII] {lambda} 9069{AA} emission line and H{beat} equivalent widths that are higher than 10{AA} in emission were included, and they are compact in appearance. We used the so-called direct method for objects with the electron-temperature-sensitive [SIII] {lambda} 6312{AA} emission line, and an empirical method based on the S23 parameter. The last provided an abundance calibration that monotonically increased up to at least the solar value, and can be applied based on the spectral range from 6000 to 9500{AA} alone. We show that the bias that is introduced when the [OIII] {lambda} 4363{AA} line is required restricts the sample to objects with an [OIII] electron temperature higher than 10000K, and their temperature distribution is then rather narrow. For objects with determinations of t_e_[SIII], the distribution is flatter and wider, which fits a more realistic scenario better. For these objects, we calculated the ionic abundances of sulphur and their ratios. In all cases, S2+ was found to be the dominant ion, with a contribution greatly exceeding that of S+. This fact justifies the adoption t_e_[SIII] as the dominant temperature throughout the nebula, although in 20% of the objects, an estimated ionization correction factor is required. For the objects in the sample that required the detection of the [OIII] {lambda} 4363{AA} line (sample 3) and [SIII] {lambda} 6312{AA}, the distribution abundances as traced directly by oxygen and sulphur appear to be very similar to each other. The median values are 12+log(O/H)=8.1 and 12+log(S/H)=6.4, which corresponds to an S/O ratio of log(S/O)=-1.7 that is close to the solar value (-1.5). However, when the restriction for weak temperature-sensitive lines is relaxed, the abundance distribution is wider and the median value is 12+log(S/H)=6.6. When the S/O ratio is assumed to be constant, the median sulphur abundance value found here would imply a median value of the oxygen abundance of 12+log(O/H)=8.3. In summary, the abundance distributions traced by sulphur can reach reliable abundances up to the solar value at least and provide a more complete picture of the metallicity distribution of HII galaxies. The method presented here only involves the red part of the spectrum (between 6000 and 9600{AA}), and the effect of reddening is weak there. Although the strong nebular [SIII] lines shift beyond the far red spectral region for high-redshift objects, present-day infrared spectrographs can overcome this difficulty. Observations made with NIRSpec on board the JWST would be able to provide data for objects with redshifts between 0 and 4.24.2025A&A...694A..61Ghttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/694/A61CatalogResearchIsServedByTAP VizieR generic servicerelated-toV/154 : Sloan Digital Sky Surveys (SDSS), Release 16 (DR16) (Ahumada+, 2020)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/694/A61https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/694/A61http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/694/A61https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/694/A61https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/694/A61http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/694/A61GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/694/A61/table1Reddening corrected emission line intensity relative to Hbeta/100IDObject numbermeta.id;meta.mainintOIII4363? The [OIII] 4363{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloatnullablee_OIII4363? Error in OIII4363stat.errorfloatnullableArIV4740? The [ArIV] 4740{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloatnullablee_ArIV4740? Error in ArIV4740stat.errorfloatnullableHbeta[100] The Hbeta value relative to Hbeta/100stat.value;spect.line;arith.ratiointe_HbetaError in Hbetastat.error;spect.linefloatOIII4959The [OIII] 4959{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloate_OIII4959Error in OIII4959stat.errorfloatOIII5007The [OIII] 5007{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloate_OIII5007Error in OIII5007stat.errorfloatSIII6312The [SIII] 6312{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloate_SIII6312Error in SIII6312stat.errorfloatHalphaHalpha reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloate_HalphaError in H_alphastat.error;spect.linefloatSII6717The [SII] 6717{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloate_SII6717Error in SII6717stat.errorfloatSII6731The [SII] 6731{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloate_SII6731Error in SII6731stat.errorfloatArIII7135? The [ArIII] 7135{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloatnullablee_ArIII7135? Error in ArIII7135stat.errorfloatnullableOII7322? The [OII] 7322{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloatnullablee_OII7322? Error in OII7322stat.errorfloatnullableOII7330? The [OII] 7330{AA} reddening corrected emission line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloatnullablee_OII7330? Error in OII7330stat.errorfloatnullableSIII9069The [SIII] 9069{AA} reddening corrected emission Line intensity relative to Hbeta/100spect.line.intensity;arith.ratiofloate_SIII9069Error in SIII9069stat.errorfloatFHbetaHbeta flux in 10^-17^erg/s/cm^2^1e-20W.m**-2phot.flux;spect.linedoublee_FHbetaError in FHbeta1e-20W.m**-2stat.errorfloatEWHbetaHbeta equivalent width0.1nmspect.line.eqWidthdoublechbetaExtintion coefficientobs.atmos.extinctionfloate_chbetaError in chbetastat.errorfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintJ/A+A/694/A61/table2Electron temperatures, ionic abundances and total oxygen and sulphur abundancerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDObject numbermeta.id;meta.mainintteOIIIOIII Electron temperature10000Kphys.temperature.electron;phys.electronfloate_teOIIIError in teOIII10000Kstat.errorfloatteSIIISIII Electron temperature10000Kphys.temperature.electron;phys.electronfloate_teSIIIError in teSIII10000Kstat.errorfloatO+12 + log(O+/H+)phys.abundfloate_O+Error in O+stat.errorfloatO2+12 + log(O2+/H+)phys.abundfloate_O2+Error in O2+stat.errorfloatS+12 + lof(S+/H+)phys.abundfloate_S+Error in S+stat.errorfloatS2+12 + log(S2+/H+)phys.abundfloate_S2+Error in S2+stat.errorfloatS3+? 12 + log(S3+/H+)phys.abundfloatnullablee_S3+? Error in S3+stat.errorfloatnullableAr2+? 12 + log(Ar2+/H+)phys.abundfloatnullablee_Ar2+? Error in Sr2+stat.errorfloatnullableAr3+? 12 + log(Ar3+/H+)phys.abundfloatnullablee_Ar3+? Error in Ar3+stat.errorfloatnullableICFIonization correction factorarith.factorfloate_ICFError in ICFstat.errorfloatO/H12 + log(O/H)phys.abundfloate_O/HError in O/Hstat.error;phys.abundfloatS/H12 + log(S/H)phys.abundfloate_S/HError in S/Hstat.error;phys.abundfloatJ/A+A/694/A61/table3Objects SDSS DR15 Plate-MJD-FiberrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintIDObject numbermeta.id;meta.mainintPlateSDSS DR15 plate numbermeta.id;instr.plateintMJDSDSS DR15 MJD numbermeta.idintFiberSDSS DR15 Fiber numbermeta.idintSpInteractive spectrum from SDSSmeta.ref.urlchar