J/A+A/687/A16ivo://CDS.VizieR/J/A+A/687/A16doi:10.26093/cds/vizier.36870016CDSIvanov V.D.Cioni M.-R.L.Dennefeld M.de Grijs R.Craig J.E.M.,van Loon J.T.Pennock C.M.Maitra C.Haberl F.2024-11-29T20:03:40Z2024-06-25T08:23:50ZCDS support team

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

cds-question@unistra.frsurveysactive-galactic-nucleimagellanic-cloudsquasarsgalaxiesphotometryinfrared-photometryspectroscopyQuasi-stellar objects (QSOs) are a basis for an absolute reference system for astrometric studies. There is a need for creating such system behind nearby galaxies, to facilitate the measuring of the proper motions of these galaxies. However, the foreground contamination from the galaxies themselves is a problem for the QSO identification. We search for new QSOs behind both Magellanic Clouds, the Magellanic Bridge, and the Magellanic Stream. We identify QSO candidates with a combination of near-infrared colors and variability criteria from the public ESO Visual and Infrared Survey Telescope for Astronomy (VISTA) Magellanic Clouds (VMC) survey. We confirm their nature from broad emission lines with low-resolution optical spectroscopy. We confirmed the QSO nature of 136 objects. They are distributed as follows: 12 behind the LMC, 37 behind the SMC, 63 behind the Bridge, and 24 behind the Stream. The QSOs span a redshift range from z~0.1 to z~2.9. A comparison of our quasar selection with the Quaia quasar catalog, based on Gaia low-resolution spectra, yields a selection and confirmation success rate of 6-19%, depending on whether the quality of the photometry, the magnitude ranges and the colors are considered. Our candidate list is rather incomplete, but the objects in it are likely to be confirmed as quasars with ~90% probability. Finally, we report a list of 3609 objects across the entire VMC survey that match our color and variability selection criteria; only 1249 of them have Gaia counterparts. Our combined infrared color and variability criteria for QSO selection prove to be efficient - ~90% of the observed candidates are bona fide QSOs and allow to generate a list of new high-probability quasar candidates.2024A&A...687A..16Ihttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/687/A16CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/687/A16https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/687/A16http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/687/A16https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/687/A16https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/687/A16http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/687/A16GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/A+A/687/A16/table1 (VMC coordinates and photometry of QSO candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/687/A16/table1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/687/A16/table1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/687/A16/table1?GETtext/xml+votable180.050000true0.1742083-73.04966670.005555555555555556Cone search capability for table J/A+A/687/A16/tableb1 (Complete list of quasar candidates in the VMC survey)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/A+A/687/A16/tableb1?https://vizier.iucaa.in/viz-bin/conesearch/J/A+A/687/A16/tableb1?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/A+A/687/A16/tableb1?GETtext/xml+votable180.050000true0.925625-72.58986110.0055555555555555564/2065 2067-2069 2082 5/8223 8237-8239 8244 8248 8257-8259 8264-8265 8280-8281 8284 8321-8326 8332 8448-8450 8704 9354 9376 9378 9384 9386 9728 6/32863 32885 32891 32943 32971 32973-32975 32980-32982 32984-32986 32996-32998 33000-33002 33027 33064-33066 33069 33128-33130 33132-33133 33140-33141 33152 33197 33199 33202 33208-33210 33283 33308-33310 33332 33336-33338 33409 33411-33413 33415 33424 33804 33824 34824-34825 37386 37408 37410-37411 37510 37516 37518 37540 37542 38920-38921 45329 45332-45333 453767.952274030004205e-20 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/A+A/687/A16?format=asciiInfrareddefaultJ/A+A/687/A16/table1VMC coordinates and photometry of QSO candidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVMCVMC identifier (VMC HH:MM:SS.ss-DD:MM:SS.s)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainYmagVMC Y band magnitudemagphot.mag;em.IR.Jfloate_YmagVMC Y band magnitude errormagstat.error;phot.magfloatJmagVMC J band magnitudemagphot.mag;em.IR.Jfloate_JmagVMC J band magnitude errormagstat.error;phot.magfloatKsmagVMC Ks band magnitudemagphot.mag;em.IR.Kfloate_KsmagVMC Ks band magnitude errormagstat.error;phot.magfloatClass[-1/1] Morphology (1)meta.codeintObjectObject namemeta.idcharONameOther namemeta.idcharJ/A+A/687/A16/table2log of the VLT spectroscopic observationsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObjectObject namemeta.id;meta.maincharObsTimeUT data and time at startstime.epochnullableExpTimeExposure timestime.duration;obs.exposurefloatAirmassSAirmass at start of observingobs.airMassfloatAirmassEAirmass at end of observingobs.airMassfloatPA[] Position angle of the slitdegpos.posAngfloatJ/A+A/687/A16/table4Derived parameters for the objectsrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObjectObject namemeta.id;meta.maincharLine? Quasar line or commentmeta.codecharlambda? Observed wavelength (1)0.1nmem.wlfloatnullablee_lambda? Observed wavelength error (1)0.1nmstat.errorfloatnullableS/NSNR at +/-20 Ang around the linestat.snrintzQSO? Quasar redshift, averaged (1)src.redshift;pos.heliocentricfloatnullablee_zQSO? Quasar redshift, error (1)stat.errorfloatnullablef_zQSORedshift quality flag (2)meta.codeintzQuaia? Quaia (Gaia-unWISE Quasar Catalog) redshift, averaged (1)src.redshift;pos.heliocentricfloatnullablee_zQuaia? Quaia redshift, error (1)stat.errorfloatnullableClassObject classificationmeta.code.class;src.classcharJ/A+A/687/A16/tableb1Complete list of quasar candidates in the VMC surveyrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintVMCVMC identifier (VMC HH:MM:SS.ss-DD:MM:SS.s)meta.id;meta.maincharRAJ2000Right ascension (J2000)pos.eq.ra;meta.mainDEJ2000Declination (J2000)pos.eq.dec;meta.mainGmag? Gaia G band magnitude (1)magphot.mag;em.optfloatnullablee_Gmag? Gaia G band magnitude error (1)magstat.error;phot.magfloatnullableYmagVMC Y band magnitudemagphot.mag;em.IR.Jfloate_YmagVMC Y band magnitude errormagstat.error;phot.magfloatJmagVMC J band magnitudemagphot.mag;em.IR.Jfloate_JmagVMC J band magnitude errormagstat.error;phot.magfloatKsmagVMC Ks band magnitudemagphot.mag;em.IR.Kfloate_KsmagVMC Ks band magnitude errormagstat.error;phot.magfloatSlopeFitted slope to the VMC Ks light curvemeta.crypticdoublee_SlopeError of the slopestat.errordoubleNptsNumber of VMC Ks epochsmeta.numberintDeltaTTime span covered by the VMC Ks light curveyrtime.intervalfloat