J/MNRAS/495/4707ivo://CDS.VizieR/J/MNRAS/495/4707doi:10.26093/cds/vizier.74954707CDSSilva M.Humphrey A.Lagos P.Morais S.G.2025-05-22T20:15:51Z2023-09-14T15:19:37ZCDS support team

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

cds-question@unistra.frquasarsactive-galactic-nucleiredshiftedspectroscopyultraviolet-astronomyvisible-astronomyWe study the ultraviolet (UV) emission-line ratios of a sample of 145 type II quasars (QSO2s) from Sloan Digital Sky Survey III Baryon Oscillation Spectroscopic Survey, and compare against a grid of active galactic nucleus (AGN) photoionization models with a range in gas density, gas chemical abundances, and ionization parameter. Most of the quasars are 'carbon-loud', with CIV/HeII ratios that are unusually high for the narrow-line region, implying higher than expected gas density (>10^6^cm^-3^) and/or significantly supersolar-relative carbon abundance. We also find that solar or supersolar nitrogen abundance and metallicity are required in the majority of our sample, with potentially significant variation between objects. Compared to radio galaxies at similar redshifts (HzRGs; z>2), the QSO2s are offset to higher NV/HeII, CIV/HeII, and CIII/HeII, suggesting systematically higher gas density and/or systematically higher C and N abundances. We find no evidence for a systematic difference in the N/C abundance ratio between the two types of objects. Scatter in the NIV/CIV ratio implies a significant scatter in the N/C abundance ratio among the QSO2s and HzRGs, consistent with differences in the chemical enrichment histories between objects. Interestingly, we find that adopting secondary behaviour for both N and C alleviates the long-standing 'NIV problem'. A subset of the QSO2s and HzRGs also appear to be 'silicon-loud', with SiIII relative fluxes suggesting Si/C and Si/O are an order of magnitude above their solar values. Finally, we propose new UV-line criteria to select genuine QSO2s with low-density narrow-line regions.2020MNRAS.495.4707Shttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/495/4707CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toJ/MNRAS/435/3306 : Candidate type II QSOs in SDSS III (Alexandroff+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/495/4707https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/495/4707http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/495/4707https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/495/4707https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/495/4707http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/495/4707GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/495/4707/tablea1 (List of flux ratios measurements of the rest-frame UV and optical of HzRGs from the literature)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/495/4707/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/495/4707/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/495/4707/tablea1?GETtext/xml+votable180.050000true191.41013.38840.005555555555555556Cone search capability for table J/MNRAS/495/4707/tablea2 (List of the first 40 type II quasars followed by the detected emission lines)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/495/4707/tablea2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/495/4707/tablea2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/495/4707/tablea2?GETtext/xml+votable180.050000true18.7777292-1.88527780.005555555555555556Cone search capability for table J/MNRAS/495/4707/tablea7 (List of objects separated according to the selection criteria presented in Section 6)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/495/4707/tablea7?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/495/4707/tablea7?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/495/4707/tablea7?GETtext/xml+votable180.050000true323.9889583-3.35834440.0055555555555555566/36 4103 4115 4134 4612-4613 4670 4708 4744 4807 5053 5394 5445 5454 5458 5517 5536 5562 5683 5704-5705 5734 5750 5830 6151 6416 6443 6572 6574 6600 8247 8527 8539 8546 8551 8590 8609 8619 8669 9024 9033 9055 9178 9230 9265 9305 9334 9345 9352 9365 9373 9396 9417 9449 9473 9732 10459 10883 10944 12361 13074 15011 15126 17659 17713 17719 17767 17783 17817 17821 17833 17846 17874 17889 17991 18026 18062 18070 18092 18105 18113 18127 18242 18247 18299 18844 18923 18989 19092 19155 19200 21878 22367 22398 25919 25945 26061 26086 26316 26334 26371 26438 26975 27245 27260 27309 27341 27684-27685 27687 28623 31332 31399 31737-31738 32506 36160 36601 40240 48347 48714https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/495/4707?format=asciiUVOpticaldefaultJ/MNRAS/495/4707/tablea1List of flux ratios measurements of the rest-frame UV and optical of HzRGs from the literaturerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintRefReferences (1)meta.refcharzRedshiftsrc.redshiftfloatOVI+CII/HeII? (OVI+CII)/HeII flux ratiophot.flux;arith.ratiofloatnullablee_OVI+CII/HeII? Error on OVI+CII/HeIIstat.errorfloatnullableLya/HeIILy{alpha}/HeII flux ratiophot.flux;arith.ratiofloate_Lya/HeIIError on Lya/HeIIphot.flux;arith.ratiofloatl_NV/HeIILimit flag on NV/HeIIphot.flux;arith.ratiocharNV/HeIINV/HeII flux ratiophot.flux;arith.ratiofloate_NV/HeII? Error on NV/HeIIphot.flux;arith.ratiofloatnullableSiIV+OIV/HeII? (SiIV+OIV)/HeII flux ratiophot.flux;arith.ratiofloatnullablee_SiIV+OIV/HeII? Error on SiIV+OIV/HeIIstat.errorfloatnullableNIV/HeII? NIV/HeII flux ratiophot.flux;arith.ratiofloatnullablee_NIV/HeII? Error on NIV/HeIIphot.flux;arith.ratiofloatnullableCIV/HeIICIV/HeII flux ratiophot.flux;arith.ratiofloate_CIV/HeIIError on CIV/HeIIphot.flux;arith.ratiofloatNeIV1602/HeII? [NeIV]1602/HeII flux ratiophot.flux;arith.ratiofloatnullableOIII/HeII? OIII/HeII flux ratiophot.flux;arith.ratiofloatnullablee_OIII/HeII? Error on OIII/HeIIstat.errorfloatnullableSiIII/HeII? SiIII/HeII flux ratiophot.flux;arith.ratiofloatnullablee_SiIII/HeII? Error on SiIII/HeIIphot.flux;arith.ratiofloatnullableCIII/HeII? CIII/HeII flux ratiophot.flux;arith.ratiofloatnullablee_CIII/HeII? Error on CIII/HeIIstat.errorfloatnullableNeIV2422/HeII? [NeIV]2422/HeII flux ratiophot.flux;arith.ratiofloatnullablee_NeIV2422/HeII? Error on NeIV2422/HeIIstat.errorfloatnullableOIII/Ha? OIII/H{alpha} flux ratiophot.flux;arith.ratiofloatnullablee_OIII/Ha? Error on OIII/Hastat.errorfloatnullablel_OIII/HbLimit flag on OIII/Hbmeta.code.errorcharOIII/Hb? OIII/H{beta} flux ratiophot.flux;arith.ratiofloatnullablee_OIII/Hb? Error on OIII/Hbstat.errorfloatnullablel_NII/HaLimit flag on NII/Hameta.code.errorcharNII/Ha? NII/H{alpha} flux ratiophot.flux;arith.ratiofloatnullablee_NII/Ha? Error on NII/Hastat.errorfloatnullablel_OII/OIIILimit flag on OII/OIIImeta.code.errorcharOII/OIII? [OII]3728/[OIII]5008 flux ratiophot.flux;arith.ratiofloatnullablee_OII/OIII? Error on OII/OIIIstat.errorfloatnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainNameSource namemeta.id;meta.maincharl_NIV/HeIILimit flag on NIV/HeIIphot.flux;arith.ratiocharSimbadNameSimbad column added by the CDSmeta.idcharnullableJ/MNRAS/495/4707/tablea2List of the first 40 type II quasars followed by the detected emission linesSimbadSimbad column added by the CDSmeta.ref.urlcharl_FNeIV1602Limit flag on FNeIV1602meta.code.errorcharFNeIV1602? [NeIV]1602 emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FNeIV1602? Error on FNeIV16021e-20W.m**-2stat.errorfloatnullableFHeII? HeII emission line flux1e-20W.m**-2phot.fluxfloatnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharzRedshiftsrc.redshiftfloatClass? QSO classification (G1)meta.code.classintnullableFOVI+CII? OVI+CII emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FOVI+CII? Error on FOVI+CII1e-20W.m**-2stat.errorfloatnullableFLyaLy{alpha} emission line flux1e-20W.m**-2phot.fluxfloate_FLyaError on FLya1e-20W.m**-2stat.errorfloatFNV? NV emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FNV? Error on FNV1e-20W.m**-2stat.errorfloatnullableFOI? OI emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FOI? Error on FOI1e-20W.m**-2stat.errorfloatnullableFSiIV+OIV? SiIV+OIV emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FSiIV+OIV? Error on FSiIV+OIV1e-20W.m**-2stat.errorfloatnullableFNIV? NIV emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FNIV? Error on FNIV1e-20W.m**-2stat.errorfloatnullableFCIVCIV emission line flux1e-20W.m**-2phot.fluxfloate_FCIVError on FCIV1e-20W.m**-2stat.errorfloate_FHeII? Error on FHeII1e-20W.m**-2stat.errorfloatnullableFOIII? OIII emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FOIII? Error on FOIII1e-20W.m**-2stat.errorfloatnullableFSiIII? SiIII emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FSiIII? Error on SiIII1e-20W.m**-2stat.errorfloatnullableFCIII? CIII emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FCIII? Error on FCIII1e-20W.m**-2stat.errorfloatnullablel_FNeIV2422Limit flag on FNeIV2422meta.code.errorcharFNeIV2422? [NeIV]2422 emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FNeIV2422? Error on FNeIV24221e-20W.m**-2stat.errorfloatnullableFMgII? MgII emission line flux1e-20W.m**-2phot.fluxfloatnullablee_FMgII? Error on MgII1e-20W.m**-2stat.errorfloatnullable_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.mainJ/MNRAS/495/4707/tablea7List of objects separated according to the selection criteria presented in Section 6zRedshiftsrc.redshiftfloatSimbadSimbad column added by the CDSmeta.ref.urlcharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name (JHHMMSS.ss+DDMMSS.s)meta.id;meta.maincharClass? QSO classification (G1)meta.code.classintnullableNV/HeII? NV/HeII flux ratiophot.flux;arith.ratiofloatnullablee_NV/HeII? Error on NV/HeIIstat.errorfloatnullableCIV/HeIICIV/HeII flux ratiophot.flux;arith.ratiofloate_CIV/HeIIError on CIV/HeIIstat.errorfloatl_NeIV2422/HeIILimit flag on NeIV2422/HeIImeta.code.errorcharNeIV2422/HeII? NeIV2422/HeII flux ratiophot.flux;arith.ratiofloatnullablee_NeIV2422/HeII? Error on NeIV2422/HeIIstat.errorfloatnullablel_NeIV2422/CIVLimit flag NeIV2422/CIVmeta.code.errorcharNeIV2422/CIV? NeIV2422/CIV flux ratiophot.flux;arith.ratiofloatnullablee_NeIV2422/CIV? Error on NeIV2422/CIVstat.errorfloatnullablel_NeIV1602/NeIV2422Limit flag on NeIV1602/NeIV2422meta.code.errorcharNeIV1602/NeIV2422? NeIV1602/NeIV2422 flux ratiophot.flux;arith.ratiofloatnullableFWHMCIVFWHM for the CIV linekm/sspect.line.widthinte_FWHMCIVError on FWHMCIVkm/sstat.errorint_RARight Ascension (J2000) from SIMBAD (not part of the original data)degpos.eq.ra;meta.main_DEDeclination (J2000) from SIMBAD (not part of the original data)degpos.eq.dec;meta.main