J/A+A/581/A33ivo://CDS.VizieR/J/A+A/581/A33doi:10.26093/cds/vizier.35810033CDSDe Ruiter H.R.Parma P.Fanti R.Fanti C.2017-12-22T05:33:18Z2016-01-15T10:57:04ZCDS support team

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

cds-question@unistra.frgalaxiesradio-galaxiesultraviolet-photometryvisible-astronomysloan-photometryinfrared-photometryWe investigate whether the far-UV continuum of nearby radio galaxies is due solely to the parent galaxy that passively evolves, or if it reveals evidence for the presence of other star-forming or non-stellar components. If the UV excess is due to an additional radiation component, we compare this with other properties such as radio power, optical spectral type (e.g. high- and low-excitation galaxies), and the strength of the emission lines. We also discuss the possible correlation between the ultraviolet flux, IR properties, and the central black hole mass. We used a sample of low-luminosity B2 radio galaxies and a small sample of higher luminosity 3C radio galaxies at comparable redshift (z<0.2). Spectral energy distributions (SEDs) were constructed using a number of on-line databases that are freely available now: GALEX, SDSS, 2MASS, and WISE. These were compared with model SEDs of early-type galaxies with passively evolving stellar populations at various ages (typically 0.5-1.3x10^9^ years). We established whether a second component was needed to obtain a satisfactory fit with the observed overall SED. We introduce the parameter XUV, which measures the excess slope of the UV continuum between 4500 and 2000{AA} with respect to the UV radiation produced by the underlying old galaxy component. We find that the UV excess as measured by XUV is usually small or absent in low-luminosity (FR I) sources, but sets in abruptly at the transition radio power, above which we find mostly FRII sources. XUV behaves very similarly to the strength of the optical emission lines (in particular H{alpha}). Below P_1.4GHz_<10^24^W/Hz XUV is close to zero. XUV correlates strongly with the H{alpha} line strength, but only in sources with strong H{alpha} emission. We discuss whether the line emission might be due to photoionization by radiation from the parent galaxy, possibly with additional star formation, or if it requires the presence of a non-stellar active galactic nucleus component. XUV and the slope of the mid-IR are strongly correlated, as measured by the WISE bands in the interval 3.4 to 22{mu}m, in the sense that sources with a strong UV excess also have stronger IR emission. There is an inverse correlation between XUV and central black hole mass: the M_BH_ of objects with strong UV excess is on average two to three times less massive than that of objects without UV excess. Low-luminosity radio galaxies tend to be more massive and contain more massive black holes.2015A&A...581A..33Dhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/581/A33CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toVIII/1 : The 3C and 3CR Catalogues (Edge+ 1959-1962)VIII/36 : The Second Bologna Survey (Colla+ 1970-1974)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/581/A33https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/581/A33http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/581/A33https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/581/A33https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/581/A33http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/581/A33GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/581/A33/table3 (GALEX, SDSS, and 2MASS magnitudes of B2 and 3C radio galaxies)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/581/A33/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/581/A33/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/581/A33/table3?GETtext/xml+votable180.050000true121.395941724.16411110.0055555555555555566/4835 4841 4954 4978 5005 5018 5023 5046 5048 5087 5206 5225 5250 5260 5284 5429 5671 5768 5817 6532 8555 8659 8669 8675 8705 8919 8927 8989 9009 9019 9022-9023 9037 9062 9104 9290 9305 9321 9327 9332-9333 9349 9368 9375 9393 9443 9464 9468 9612 10271 10312 10318 10322 10355 10379 10387 10401 10416 10424 10440 10442 10471 10839 11408 11512 19949 24053 27765 27773 28127 28145 28249 28378 28407 28409 28440 28495 28626 28649 28654 32394 326851.1166583743361574e-19 1.4134638842407062e-18https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/581/A33?format=asciiRadioUVOpticalInfrareddefaultJ/A+A/581/A33/table2WISE magnitudes of B2 and 3C radio galaxiese_W1magrms uncertainty on W1magmagstat.error;phot.magfloatW2magWise W2 magnitudemagphot.mag;em.IR.4-8umfloate_W2magrms uncertainty on W2magmagstat.error;phot.magfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name (B2 HHMM+DDA or 3C NNN.N)meta.id;meta.maincharW1magWise W1 magnitudemagphot.mag;em.IR.3-4umfloatW3magWise W3 magnitudemagphot.flux.density;em.IR.8-15umfloate_W3magrms uncertainty on W3magmagstat.error;phot.magfloatW4mag? Wise W4 magnitudemagphot.flux.density;em.IR.15-30umfloatnullablee_W4mag? rms uncertainty on W4magmagstat.error;phot.magfloatnullableJ/A+A/581/A33/table3GALEX, SDSS, and 2MASS magnitudes of B2 and 3C radio galaxiesSimbadNameSimbad column added by the CDSmeta.idchare_Kmagrms uncertainty on Kmagmagstat.error;phot.mag;em.IR.KfloatrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintNameSource name (B2 HHMM+DDA or 3C NNN.N)meta.id;meta.maincharFUV? GALEX FUV magnitudemagphot.mag;em.UV.100-200nmfloatnullablee_FUV? rms uncertainty on FUVmagstat.errorfloatnullableNUV? GALEX NUV magnitudemagphot.mag;em.UVfloatnullablee_NUV? rms uncertainty on NUVmagstat.errorfloatnullableumagSDSS u magnitudemagphot.mag;em.opt.UfloatgmagSDSS g magnitudemagphot.mag;em.opt.BfloatrmagSDSS r magnitudemagphot.mag;em.opt.RfloatimagSDSS i magnitudemagphot.mag;em.opt.IfloatzmagSDSS z magnitudemagphot.mag;em.opt.IfloatJmag2MASS J magnitudemagphot.mag;em.IR.Jfloate_Jmagrms uncertainty on Jmagmagstat.error;phot.mag;em.IR.JfloatHmag2MASS H magnitudemagphot.mag;em.IR.Hfloate_Hmagrms uncertainty on Hmagmagstat.error;phot.mag;em.IR.HfloatKmag2MASS K magnitudemagphot.mag;em.IR.Kfloat_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/A+A/581/A33/table4Radio and optical parametersNameSource name (B2 HHMM+DDA or 3C NNN.N)meta.id;meta.maincharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintlogMGalaxy masslog(solMass)phys.massfloatAgeGalaxy age1e+09yrtime.agefloatC1g? 2nd galaxy component logM for a (young) galaxy modellog(solMass)phys.massfloatnullableC2g? 2nd component Age for a (young) galaxy modelyrpos.cartesiandoublenullableg[g] g for galaxy modelmeta.codecharC1p? 2nd galaxy component luminosity density (in L_{sun}/{AA}), at the reference point {lambda}=2000{AA}, L_p.l_^2000{AA}^, for a power lawlog(10solLum/nm)phys.luminosityfloatnullableC2p? 2nd galaxy component slope of power-law (lambda^-alpha^), for a power lawspect.indexfloatnullablep[p] p for power lawmeta.codecharchi2minReduced minimum chi^2^ valuestat.fit.chi2floatn_chi2min[cd] Note on chi2min (1)meta.notecharlogP? Total power at 1.4GHzphys.luminosity;em.radio.750-1500MHzfloatnullableFR? FR type (2)meta.code.classfloatnullableSpCode[0/4]? Spectral type code (3)meta.code.classintnullableClassClassification of the spectral type according to the emission line ratios determined here (4)meta.code.classcharl_LHaLimit flag on LHameta.code.errorcharLHa? Luminosity of H{alpha} emission1e+33Wphys.luminosity;em.line.HalphafloatnullableXUV? Ultraviolet excessmagphot.color.excessfloatnullablee_XUV? rms uncertainty on XUVmagstat.errorfloatnullablelogRw? Logarithm of the ratio of the two near-IR (W1 plus W2) and the two MIR (W3 and W4) WISE luminosities, log[L(W1+W2)/L(W3+W4)]phys.luminosity;arith.ratiofloatnullablelogMBH? Black hole masslog(solMass)phys.massfloatnullabler_logMBH[efg] reference for logMBH (5)meta.ref;pos.framechar