J/A+A/683/A157ivo://CDS.VizieR/J/A+A/683/A157doi:10.26093/cds/vizier.36830157CDSVejlgaard S.Fynbo J.P.U.Heintz K.E.Krogager J.K.Moller P.,Geier S.J.Christensen L.Ma G.2024-11-29T20:01:05Z2024-03-15T08:40:22ZCDS support team

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

cds-question@unistra.frquasarsactive-galactic-nucleiradio-sourcesphotometryvisible-astronomyinfrared-astronomyThe dichotomy between red and blue quasars is still an open question. It is debated whether red quasars are simply blue quasars that are observed at certain inclination angles or if they provide insight into a transitional phase in the evolution of quasars. We investigate the relation between quasar colors and radio-detected fraction because radio observations of quasars provide a powerful tool in distinguishing between quasar models. We present the eHAQ+GAIA23 sample, which contains quasars from the High A(V) Quasar (HAQ) Survey, the Extended High A(V) Quasar (eHAQ) Survey, and the Gaia quasar survey. All quasars in this sample have been found using a near-infrared color selection of target candidates that have otherwise been missed by the Sloan Digital Sky Survey (SDSS). We implemented a redshift-dependent color cut in g'-i' to select red quasars in the sample and divided them into redshift bins, while using a nearest neighbors algorithm to control for luminosity and redshift differences between our red quasar sample and a selected blue sample from the SDSS.Within each bin, we cross-matched the quasars to the Faint Images of the Radio Sky at Twenty centimeters (FIRST) survey and determined the radio-detection fraction. For redshifts 0.8<z<=1.5, the red and blue quasars have a radio-detection fraction of 0.153^+0.037^_-0.032_ and 0.132^+0.034^_-0.030_, respectively. The red and blue quasars with redshifts 1.5<z<=2.4 have radio-detection fractions of 0.059+0.019_-0.016_ and 0.060^+0.019^_-0.016_, respectively, and the red and blue quasars with redshifts z>2.4 have radio-detection fractions of 0.029^+0.017^_-0.012_ and 0.058^+0.024^_-0.019_, respectively. For the WISE color-selected red quasars, we find a radio-detection fraction of 0.160^+0.038^_-0.034_ for redshifts 0.8<z<=1.5, 0.063^+0.020^_-0.017_ for redshifts 1.5<z<=2.4, and 0.051^+0.030^_-0.022_ for redshifts z>2.4. In other words, we find similar radio-detection fractions for red and blue quasars within <1{sigma} uncertainty, independent of redshift. This disagrees with what has been found in the literature for red quasars in SDSS. It should be noted that the fraction of broad absorption line (BAL) quasars in red SDSS quasars is about five times lower. BAL quasars have been observed to be more frequently radio quiet than other quasars, therefore the difference in BAL fractions could explain the difference in radio-detection fraction. The dusty torus of a quasar is transparent to radio emission. When we do not observe a difference between red and blue quasars, it leads us to argue that orientation is the main cause of quasar redness. Moreover, the observed higher proportion of BAL quasars in our dataset relative to the SDSS sample, along with the higher rate of radio detections, indicates an association of the redness of quasars and the inherent BAL fraction within the overall quasar population. This correlation suggests that the redness of quasars is intertwined with the inherent occurrence of BAL quasars within the entire population of quasars. In other words, the question why some quasars appear red or exhibit BAL characteristics might not be isolated; it could be directly related to the overall prevalence of BAL quasars in the quasar population. This finding highlights the need to explore the underlying factors contributing to both the redness and the frequency of BAL quasars, as they appear to be interconnected phenomena.2024A&A...683A.157Vhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/683/A157CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/683/A157https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/683/A157http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/683/A157https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/683/A157https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/683/A157http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/683/A157GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/683/A157/tablea1 (Spectroscopic redshift and astrometric and photometric data)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/683/A157/tablea1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/683/A157/tablea1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/683/A157/tablea1?GETtext/xml+votable180.050000true336.93830.3713330.0055555555555555565/7037 6/1 8 15 21 40 64 66 131 160 521 640 2069 2142 2188 4102 4105-4106 4128 4152 4160 4174 4195 4225-4226 4256 4260 4352 4358 4366 8201 8217 8232 8236 8249 8270 8327 8348 8389 8663 8936 8942 9161-9162 9255 9258 9277 9318-9319 9325 9327 9329 9347 9359 9366 9380 10255 10305 10365 10381 10396 10398-10399 10410 10435 10438 10448 10466 10469 10530 10765 12289 12753 13352 13423 13509 13513 13517 16439 16522 16525 16529 16546 16554 17319 17327 17336 17338 17586 17629 17663 17670 17725 17747 17754 17769 17777 17813 17838 17845 17853 17882 17884 17889 17895 17898 17901 17926 17944 17965 18026 18032 18036 18043 18045 18061 18072 18095-18096 18099 18102 18108 18117 18155 18162 18173-18174 18178 18192 18196 18208-18209 18214 18218 18223 18227 18229 18243-18244 18301 18308 18311 18318 18320 18333 18341 18350-18351 18361-18363 18370 18372 18396 18416 18429 18692 18772 18777 18779 18781 18786 18794 18798 18801-18802 18842 18845-18846 18850-18851 18869 18871 18875 18879 18887 18900 18911-18912 18917 18920 18923 18928 18931-18932 19029 19032 19044 19053 19066 19068 19093 19107 19109 19203 19208 19212 19217 19222 19230 19235 19239 19245 19248 19252 19255 19271 19274 19280 19282 19297 19299-19300 19315 19318 19456 19462 19464 19470-19471 19478 19503-19505 19518 19524 19526 19529-19531 19539 19548 19553-19554 19558 19569 19576 19578 19587-19588 19592 19600 19623 19641 19644 19647-19648 19663 19668 19670 19673 19677 19685-19686 19689 19721 19727 19742 19746 19750-19751 19829 19885 19909 19968 19972 19976 19978 19980 19982 19989-19990 20005 20034 20066 21837 21841 21849 21851-21852 21860 21874-21875 21969 23139 23144-23146 23186-23187 23191 23195 23212 23217 23233 23245 23268 23277-23278 24400 25908-25909 25913 25918-25919 25926-25927 25933 25935 25942-25945 25950-25951 25960 25963-25964 25973 26005-26006 26008 26020 26028-26029 26031 26037 26049 26069 26246 26275 26279 26299 26367 26369 26409 26437 26453 26530 26574 26588 26602 26873 26951 26960 26992 27080 27085 27104 27127 27268 27275 27297 27305 27310 27315-27316 27318 27354 27367 27473 27522 27554 27574 27584 27598 27648 27659 27674 27690 27702 27726 27755 27783 27791 27800 27836 27843-27844 27858 27862 27865 27915 27936 28111 28127 28175 28178 28186 28195 28197 28211 30039-30041 30043-30044 30064 31292 31338 31382 31398 31409 31414-31415 31434 31451 31460-31461 31467 35321 35903 35912 35974 40954-40955 40957 45043 45050 45055 46573 46578 46581 46583-46584 46586 46878 46913 46916 46918 46920 46922-46923 46928 46930-46931 46933-46936 46944-46945 46950 46982 491498.157980699529898e-21 6.090060298487514e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/683/A157?format=asciiOpticalInfraredRadiodefaultJ/A+A/683/A157/tablea1Spectroscopic redshift and astrometric and photometric datarecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintSeq[0/534] Sequential numbermeta.recordintNameNamemeta.id;meta.maincharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainQSO[1] is a QSO ?meta.codefloatBAL[0/1] is a BAL ?meta.codefloatRED[0/1] is a red-QSO ?meta.codefloatFIRST[0/1] is FIRST detected ?meta.codefloatFint1.4? FIRST integrated fluxmJyphot.flux.density;em.radio.750-1500MHzfloatnullablezRedshiftsrc.redshiftfloatumag? SDSS u (3543{AA}) band magnitudemagphot.mag;em.opt.Udoublenullablee_umag? rms uncertainty on umagmagstat.error;phot.magdoublenullablegmagSDSS g (4770{AA}) band magnitudemagphot.mag;em.opt.Bdoublee_gmagrms uncertainty on gmagmagstat.error;phot.magdoublermagSDSS r (6231{AA}) band magnitudemagphot.mag;em.opt.Rdoublee_rmagrms uncertainty on rmagmagstat.error;phot.magdoubleimagSDSS i (7623{AA}) band magnitudemagphot.mag;em.opt.Idoublee_imagrms uncertainty on imagmagstat.error;phot.magdoublezmagSDSS z (9124{AA}) band magnitudemagphot.mag;em.opt.Idoublee_zmagrms uncertainty on zmagmagstat.error;phot.magdoubleYmag? UKIDSS Y band magnitudemagphot.mag;em.IR.Jdoublenullablee_Ymag? rms uncertainty on Ymagmagstat.error;phot.magdoublenullableJmag? UKIDSS J band magnitudemagphot.mag;em.IR.Jdoublenullablee_Jmag? rms uncertainty on Jmagmagstat.error;phot.magdoublenullableHmag? UKIDSS H band magnitudemagphot.mag;em.IR.Hdoublenullablee_Hmag? rms uncertainty on Hmagmagstat.error;phot.magdoublenullableKmag? UKIDSS K band magnitudemagphot.mag;em.IR.Kdoublenullablee_Kmag? rms uncertainty on Kmagmagstat.error;phot.magdoublenullableW1magWISE W1 magnitudemagphot.mag;em.IR.3-4umdoublee_W1magrms uncertainty on W1magmagstat.error;phot.magfloatW2magWISE W2 magnitudemagphot.mag;em.IR.4-8umfloate_W2mag? rms uncertainty on W2magmagstat.error;phot.magfloatnullableW3magWISE W3 magnitudemagphot.flux.density;em.IR.8-15umfloate_W3mag? rms uncertainty on W3magmagstat.error;phot.magfloatnullableW4magWISE W4 magnitudemagphot.flux.density;em.IR.15-30umfloate_W4mag? rms uncertainty on W4magmagstat.error;phot.magfloatnullableRefReferences (1)meta.refchar