J/MNRAS/481/307ivo://CDS.VizieR/J/MNRAS/481/307doi:10.26093/cds/vizier.74810307CDSKostrzewa-Rutkowska Z.Jonker P.G.Hodgkin S.T.Wyrzykowski L.,Fraser M.Harrison D.L.Rixon G.Yoldas A.Van Leeuwen F.Delgado A.,Van Leeuwen M.Koposov S.E.2024-08-18T20:21:44Z2018-12-18T07:08:33ZCDS support team

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

cds-question@unistra.frsurveysactive-galactic-nucleisupernovaeThe high spatial resolution and precise astrometry and photometry of the Gaia mission should make it particularly apt at discovering and resolving transients occurring in, or near, the centres of galaxies. Indeed, some nuclear transients are reported by the Gaia Science Alerts (GSA) team, but not a single confirmed tidal disruption event (TDE) has been published. In order to explore the sensitivity of GSA, we performed an independent and systematic search for nuclear transients using Gaia observations. Our transient search is driven from an input galaxy catalogue (derived from the Sloan Digital Sky Survey Release 12). We present a candidate detection metric that is independent from the existing GSA methodology, to see if Gaia Alerts are biased against the discovery of nuclear transients, and in particular which steps may have an impact. Our technique does require significant manual vetting of candidates, making implementation in the GSA system impractical for daily operations, although it could be run weekly, which for month-to-year long transients would make a scientifically valuable addition. Our search yielded 480 nuclear transients, 5 of which were alerted and published by GSA. The list of (in some cases ongoing) transients includes candidates for events related to enhanced accretion on to a super-massive black hole and TDEs. An implementation of the detection methodology and criteria used in this paper as an extension of GSA could open up the possibility for Gaia to fulfil the role as a main tool to find transient nuclear activity as predicted in the literature.2018MNRAS.481..307Khttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/MNRAS/481/307CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toI/345 : Gaia DR2 (Gaia Collaboration, 2018)V/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/MNRAS/481/307https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/MNRAS/481/307http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/MNRAS/481/307https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/MNRAS/481/307https://vizier.iucaa.in/viz-bin/votable?-source=J/MNRAS/481/307http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/MNRAS/481/307GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/MNRAS/481/307/table2 (List of GNT candidates)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/MNRAS/481/307/table2?https://vizier.iucaa.in/viz-bin/conesearch/J/MNRAS/481/307/table2?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/MNRAS/481/307/table2?GETtext/xml+votable180.050000true0.33945-0.194530.0055555555555555566/308 317 424 544 678 683 830 909 2090 2280 2570 2619 2818 3945 4135 4139 4145 4196 4286 4296 4327 4372 4394 4421 4428 4463 4532 4607 4617 4629 4668 4674 4684 4700 4820 4832 4839 4850 4855 4863 4882 4908 4940 4954 4969 5002 5012 5017 5039 5049 5071 5090 5097 5125 5158 5210 5278 5336 5489 5491 5507 5515 5537 5546 5557 5582 5614 5619 5714 5724 5742 5754-5755 5816 5838 5878 5921 5945 5963 5975 5983 6021 6027 6068 6129 6209 6440 6492 6536 6582 6611 6623 6736-6737 6838 6928 7185-7186 7189 7221 7227 7235 7268 7300 7308 7326 7330 7359 7367 7369 7375 7385 7390-7391 7444 7449 7463 7478 7489 7523 7603 7639 7823 8306 8373 8395 8452 8456 8575 8608 8619 8629 8648 8654 8695 8716 8813 8840 8881 8887 8908 8912 8946 9021 9033 9078 9091 9133 9135 9145 9148-9149 9166 9173 9245 9258 9294 9297 9303 9313 9320 9323 9365 9377 9424 9455-9457 9470 9477-9478 9509 9513 9520 9578 9608-9609 9623 9638 9719 9743 9751 9802 9817 9888 9929 10030 10232 10284 10333 10364 10368 10583 10633 10646 10674 10751 10819 10851 10897 10901 10924 10947 10981 10988 11002 11004 11014 11022 11062 11146 11170 11206 11211 11218 11236 11284 11298 11307-11308 11318 11325 11330 11337 11342 11360 11375 11380 11475 11483 11507 11528 11533 11603 11609 11648 11782 11809 11847 11931 11933 12295 12299 12347 12544 12614 12653 12691 12773 12784 13392 13404 13433 13488 13512 13522 13531 13561 13585 13656 13682 13691 13807 13904 14945 15014 15898 16274 16998 17214 17273 17297 17360 17401 17500 17515-17516 17561 17573 17607 17623 17625 17659 17737 17740 17816 17837 17859 17895 17970 18009 18028 18072 18081 18090 18174 18181 18266 18276 18307 18318 18336 18343 18346 18374 18396 18558 18728 18774 18782 18802 18835 18892 18965 19083 19114 19386 19444 19458 19472 19523 19539 19563 19572 19576 19602 19607 19618 19622 19650 19700 19734 19745 19748 19756 19779 19845-19846 19859 19895 19919 19949 19960 19993 20009 20012 20038 20041 20058 20082 20165 20167 20177 20185 20190 20274 20283 20300 20302 20309 20315 20328 20341 20350 20364 20418 20435 21763 21847 21882 21917 21923 21959 22348 22360 22366 22396 22515 22717 22735 22764 22797 22857 22977 23065 23076 24103 24108 25037 25060 25222 25229 25428 25848 25854 25986 26000 26020 26046 26074 26088 26094-26095 26148 26186 26198 26202 26286 26328 26344 26401 26414 26504-26505 26532 26549 26577 26596 26601 26616 27020 27028 27033 27065 27116 27118 27127 27209 27255 27392 27505 27509 27528 27650 27688 27738 27841 27862 28031 28110 28243 28382 28520 28549 28553 28570 28580 28639 28643 30818 31126 31331 31338 31402 31414 31470 31486 31694 31906 31915 32288 32299 32325 32371 32408 32442 32480 32494 32500 36784 36839 45054 48756 48884 48909 490861.9867573869263685e-19 3.916500758235022e-19https://cdsarc.cds.unistra.fr/viz-bin/moc/J/MNRAS/481/307?format=asciidefaultJ/MNRAS/481/307/table2List of GNT candidatesSimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintmoreindicates data in other tablesmeta.ref.urlcharLCShow the Gaia g-band light curvemeta.ref.urlcharGNTGNT ID (GNTJHHMMSS.ss+DDMMSS.ss)meta.id;meta.maincharprimarySDSSSDSS galaxy ID (SDSSJHHMMSS.ss+DDMMSS.ss)meta.id;src.class.starGalaxycharRAJ2000Right ascension (J2000)degpos.eq.ra;meta.mainDEJ2000Declination (J2000)degpos.eq.dec;meta.mainrmagSDSS r-band brightnessmagphot.mag;em.opt.Rfloate_rmagSDSS r-band brightness errormagstat.error;phot.magfloatGmagGaia G-band median brightnessmagphot.mag;em.optfloate_GmagGaia G-band median brightness errormagstat.error;phot.magfloatGmagpGaia G-band peak brightnessmagphot.mag;em.optfloate_GmagpGaia G-band peak brightness errormagstat.error;phot.magfloatJDJD at the time of the peak (JD-2456000)dtime.epochfloatgammaSkewness parameterstat.fit.paramfloatetavon Neumann parameterstat.fit.paramfloatClassSDSS classsrc.classcharz? SDSS redshiftsrc.redshiftdoublenullablee_z? SDSS redshift errorstat.error;src.redshiftdoublenullableSloanDisplay the online SDSS data for this objectmeta.ref.urlcharJ/MNRAS/481/307/table3The GNT candidates previously alerted and published by GSA pipelinerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGSAGSA ID (GaiaNNaaa)meta.idcharGNTGNT ID (GNTJHHMMSS.ss+DDMMSS.ss)meta.id;meta.maincharSDSSSDSS galaxy ID (SDSSJHHMMSS.ss+DDMMSS.ss)meta.id;src.class.starGalaxycharADateAlerting date by GSAtime.epochnullableJDpeakJD at the time of the peaktime.epochnullableJ/MNRAS/481/307/table4An overview of optical spectroscopy of the targets and instrumental set-ups used to classify the most recent nuclear transient candidatesrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGNTGNT ID (GNTJHHMMSS.ss+DDMMSS.ss)meta.id;meta.maincharDateObservation datetime.epoch;obsnullableInstInstrument (All spectra were taken with WHT)meta.id;instrcharGratingGratingmeta.notecharSlitSlit widtharcsecspect.line.widthfloatSeeing1Seeing, or lower value of Seeing intervalarcsecinstr.obsty.seeingfloatSeeing2? Upper value of Seeing intervalarcsecinstr.obsty.seeing;stat.maxfloatnullableRange1Lower value of wavelenght range0.1nminstr.bandwidth;stat.minintRange2Upper value of wavelenght range0.1nminstr.bandwidth;stat.maxintTexpExposure timestime.duration;obs.exposureintNExpNumber of exposuremeta.numberintsp1Show the spectrummeta.ref.urlcharsp2Show the spectrummeta.ref.urlcharsp3Show the spectrummeta.ref.urlcharsp4Show the spectrummeta.ref.urlcharFileName1First spectrum file name in subdirectory spmeta.id;meta.filecharFileName2Second spectrum file name in subdirectory spmeta.id;meta.filecharFileName3Third spectrum file name in subdirectory spmeta.id;meta.filecharFileName4Fourth spectrum file name in subdirectory spmeta.id;meta.filecharJ/MNRAS/481/307/table6The GNT candidates detected by GSA AlertPipe but not published due to subsequent filteringrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintGNTGNT ID (GNTJHHMMSS.ss+DDMMSS.ss)meta.id;meta.maincharSDSSSDSS galaxy ID (SDSSJHHMMSS.ss+DDMMSS.ss)meta.id;src.class.starGalaxychar