J/MNRAS/504/5556ivo://CDS.VizieR/J/MNRAS/504/5556doi:10.26093/cds/vizier.75045556CDSTimlin J.D.Brandt W.N.Laor A.2024-08-21T20:17:49Z2021-06-09T04:36:21ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleiquasarsx-ray-sourcesredshiftedline-intensitiesWe present an investigation of the interdependence of the optical-to-X-ray spectral slope (aox), the HeII equivalent-width (EW), and the monochromatic luminosity at 2500{AA} (L2500). The values of {alpha}_ox_ and HeII EW are indicators of the strength/shape of the quasar ionizing continuum, from the ultraviolet (UV; 1500-2500{AA}), through the extreme ultraviolet (EUV;300-50{AA}), to the X-ray (2keV) regime. For this investigation, we measure the HeII EW of 206 radio-quiet quasars devoid of broad absorption lines that have high-quality spectral observations of the UV and 2keV X-rays. The sample spans wide redshift (z~0.13-3.5) and luminosity (logL_2500_~29.2-32.5erg/s/Hz) ranges. We recover the well-known {alpha}_ox_-L_2500_ and HeII EW-L_2500_ anti-correlations, and we find a similarly strong correlation between {alpha}_ox_ and HeII EW, and thus the overall spectral shape from the UV, through the EUV, to the X-ray regime is largely set by luminosity. A significant {alpha}_ox_-HeII EW correlation remains after removing the contribution of L_2500_ from each quantity, and thus the emission in the EUV and the X-rays are also directly tied. This set of relations is surprising, since the UV, EUV, and X-ray emission are expected to be formed in three physically distinct regions. Our results indicate the presence of a redshift-independent physical mechanism that couples the continuum emission from these three different regions, and thus controls the overall continuum shape from the UV to the X-ray regime.2021MNRAS.504.5556Thttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/504/5556CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/504/5556https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/504/5556http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/504/5556https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/504/5556https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/504/5556http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/504/5556GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/504/5556/tablea1 (The HeII EW data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/504/5556/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/504/5556/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/504/5556/tablea1?GETtext/xml+votable180.050000true20.48350714.8066420.005555555555555556Cone search capability for table J/MNRAS/504/5556/tableb1 (X-ray properties of the 26 high-luminosity (High-L) quasars from Chandra Cycle 13)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/504/5556/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/504/5556/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/504/5556/tableb1?GETtext/xml+votable180.050000true21.0520000457764-1.01400005817410.0055555555555555565/2856 6/4301 4378 5082 5349 5437 5687 5723 5731 6236 6391 6576 6591 7168 7307 7399 7500 8521 9262 9774 9855 10162 10578 10706 10709 10743 10749 11214 11339 11403 11418 11428 11430 11432-11433 11596 11785 11854 11924 11940 17813 18004 18406 18521 19087 19746 19883 19932 21885 23210 25742 26509 27365 27441 27578 27649 27691 27720 28034 28086 28356 28389 28416 28426 28471 28611 28648 44785https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/504/5556?format=asciiX-raydefaultJ/MNRAS/504/5556/tablea1The HeII EW datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintB1indicates data in table B1meta.ref.urlcharSampleName of the original sample (Sample) (1)meta.id;src.samplecharNameID from the original sample (ID) (2)meta.id;meta.maincharprimaryRAJ2000Right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (DEC)degpos.eq.dec;meta.mainzRedshift (z)src.redshiftdoublelog(EWHeII)log of the rest-frame HeII equivalent width (log10(HeII_EW))log(0.1nm)spect.line.eqWidthfloate_log(EWHeII)Uncertainty in log(HeIIEW) (err_logHeII)log(0.1nm)stat.errorfloatHeIIdet[0/1] HeII line detection (HeII_det)instr.saturation;spect.lineintlog(L2500)log rest-frame 2500 angstrom luminosity (log10(L2500))log(1e-07W.Hz**-1)phys.luminosityfloatlog(L2keV)log of rest-frame 2keV luminosity (log10(L2keV))log(mW.m**-2.Hz**-1)phys.luminosity;em.X-rayfloate_log(L2keV)[]? Uncertainty in log(L2keV) (err_log10(L2keV))log(mW.m**-2.Hz**-1)stat.errorfloatnullableaoxX-ray-to-optical index (aox)phys.luminosity;arith.ratiofloate_aoxuncertainty in aox (err_aox)stat.errorfloatXdetDetected in Xrays (Xdet)meta.codeintlogEWCIVlog rest-frame CIV EW (angstrom (CIV_EW)log(0.1nm)spect.line.eqWidthdoublee_logEWCIV[] Uncertainty in logCIVEW (CIV_EW_ERR)log(0.1nm)stat.errordoubleSimbadNameSimbad column added by the CDSmeta.idcharJ/MNRAS/504/5556/tableb1X-ray properties of the 26 high-luminosity (High-L) quasars from Chandra Cycle 13zRedshift (Z)src.redshiftdoublerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSDSS Name (NAME)meta.id;meta.maincharRAJ2000Right ascension (J2000) (RA)degpos.eq.ra;meta.mainDEJ2000Declination (J2000) (DEC)degpos.eq.dec;meta.mainlogNHGalactic column density (LOGNH)log(cm.s**-2)phys.columnDensity;pos.galacticfloatimagObserved i-band magnitude (imag_obs)magphot.mag;em.opt.IfloatiMAGAbsolute i-band magnitude (corrected to z=2) (Mi_Z2)magphys.magAbsdoubleObsIDChandra observation ID (ObsID)meta.id;obscharThetaChandra off-axis angle (arcmin) (THETA)arcmininstr.offsetdoubleEtimeSSoft-band effective exposure time (Exposure_eff_soft)stime.duration;obs.exposurefloatEtimeHHard-band effective exposure time (Exposure_eff_hard)stime.duration;obs.exposurefloatEtimeFFull-band effective exposure time (Exposure_eff_full)stime.duration;obs.exposurefloatPbsoftBinomial probability of detection (soft) (Pb_soft)stat.fit.goodnessdoublePbhardBinomial probability of detection (hard) (Pb_hard)stat.fit.goodnessdoublePbfullBinomial probability of detection (full) (Pb_full)stat.fit.goodnessdoubleSoftCTrRaw source counts (soft) (Soft_cts_raw)ctphot.count;em.X-rayintSoftCTbgrRaw background counts (soft) (Soft_bg_raw)ctphot.count;em.X-rayintSoftCTSoft-band net counts (or 90% confidence (Soft_cts)ctphot.count;em.X-raydoublee_SoftCTSoft lower limit (Soft_cts_merr)ctstat.errordoubleE_SoftCTSoft upper limit (Soft_cts_perr)ctstat.error;stat.maxdoubleHardCTrRaw source counts (hard) (Hard_cts_raw)ctphot.count;em.X-rayintHardCTbgrRaw background counts (hard) (Hard_bg_raw)ctinstr.backgroundintHardCTHard-band net counts (or 90% confidence (Hard_cts)ctphot.count;em.X-raydoublee_HardCTHard lower limit (Hard_cts_merr)ctstat.errordoubleE_HardCTHard upper limit (Hard_cts_perr)ctstat.error;stat.maxdoubleFullCTrRaw source counts (full) (Full_cts_raw)ctphot.count;em.X-rayintFullCTbgrRaw background counts (full) (Full_bg_raw)ctinstr.backgroundintFullCTFull-band net counts (or 90% confidence) (Full_cts)ctphot.count;em.X-raydoublee_FullCTFull lower limit (Full_cts_merr)ctstat.errordoubleE_FullCTFull upper limit (Full_cts_perr)ctstat.error;stat.maxdoubleSRC-expSMean exposure-map pixel value of the ion (soft band) (MEAN_SRC_EXP_s)cm**2.sstat.value;stat.meandoubleBG-expSMean exposure-map pixel value of the regions (soft band) (MEAN_BG_EXP_s)cm**2.sstat.value;stat.meandoubleSRC-expHMean exposure-map pixel value of the ions (hard band) (MEAN_SRC_EXP_h)cm**2.sstat.value;stat.meandoubleBG-expHMean exposure-map pixel value of the background regions (hard band) (MEAN_BG_EXP_h)cm**2.sinstr.background;stat.meandoubleSRC-expFMean exposure-map pixel value of the ions (full band) (MEAN_SRC_EXP_f)cm**2.sstat.value;stat.meandoubleBG-expFMean exposure-map pixel value of the regions (full band) (MEAN_BG_EXP_f)cm**2.sstat.value;stat.meandoubleHRHardness ratio (HRat)phot.flux;arith.ratiofloate_HRHardness ratio low limit (HR_lolim)stat.errordoubleE_HRHardness ratio upper limit (HR_uplim)stat.error;stat.maxdoubleGammaPower-law photon index (dual-band detections) or limit (single-band detection) (Gamma)meta.code;spect.indexfloate_GammaPower-law photon index lower limit (Gamma_lolim)stat.errorfloatE_GammaPower-law photon index upper limit (Gamma_uplim)stat.error;stat.maxfloatSoftCRSoft-band count rate (Soft_Count_rate)ct/sphot.count;em.X-raydoublee_SoftCRSoft-band count rate lower limit (Soft_Count_rate_merr)ct/sstat.errordoubleE_SoftCRSoft-band count rate upper limit (Soft_Count_rate_perr)ct/sstat.error;stat.maxdoubleHardCRHard-band count rate (Hard_Count_rate)ct/sphot.count;em.X-raydoublee_HardCRHard-band count rate lower limit (Hard_Count_rate_merr)ct/sstat.errordoubleE_HardCRHard-band count rate upper limit (Hard_Count_rate_perr)ct/sstat.error;stat.maxdoubleFullCRFull-band count rate (Full_Count_rate)ct/sphot.count;em.X-raydoublee_FullCRFull-band count rate lower limit (Full_Count_rate_merr)ct/sstat.errordoubleE_FullCRFull-band count rate upper limit (Full_Count_rate_perr)ct/sstat.error;stat.maxdoubleSoftSObserved flux density at rest-frame 2keV (Soft_density)mW.m**-2.Hz**-1phot.flux;em.X-raydoublee_SoftSObserved flux density at rest-frame 2keV lower limit (Soft_density_lolim)mW.m**-2.Hz**-1stat.errordoubleE_SoftSObserved flux density at rest-frame 2keV upper limit (Soft_density_uplim)mW.m**-2.Hz**-1stat.error;stat.maxdoublef2500Observed flux density at rest-frame 2500{AA} (f2500)mW.m**-2.Hz**-1phot.flux;em.UVdoublelogL2500Rest-frame 2500 {AA} monochromatic luminosity (logL_2500)log(1e-07W.Hz**-1)phys.luminosityfloataoxObserved X-ray-to-optical index (alphaox)phys.luminosity;arith.ratiodoublee_aox[] Observed aox lower limit (alphaox_lolim)stat.errordoubleE_aox[] Observed aox upper limit (alphaox_uplim)stat.error;stat.maxdoubleSimbadSimbad column added by the CDSmeta.ref.urlchar