J/ApJ/896/10ivo://CDS.VizieR/J/ApJ/896/10doi:10.26093/cds/vizier.18960010CDSBaldassare V.F.Geha M.Greene J.2022-09-21T08:32:10Z2021-10-25T07:59:06ZCDS support team

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

cds-question@unistra.frgalaxiesactive-galactic-nucleiphotometryvisible-astronomyredshiftedWe present an analysis of the long-term optical variability for ~50000 nearby (z<0.055) galaxies from the NASA-Sloan Atlas (NSA), 35000 of which are low-mass (M_*_<10^10^M_{sun}_). We use difference imaging of Palomar Transient Factory (PTF) R-band observations to construct light curves with typical baselines of several years. We then search for subtle variations in the nuclear light output. We determine whether detected variability is AGN-like by assessing the fit quality to a damped random walk model. We identify 417 variability-selected AGNs, including 237 with stellar masses between 10^7^ and 10^10^M_{sun}_. 75% of low-mass galaxies with AGN-like variability have narrow emission lines dominated by star formation. After controlling for nucleus magnitude, the fraction of variable AGNs is constant down to M_*_=10^9^M_{sun}_, suggesting no drastic decline in the BH occupation fraction down to this stellar mass regime. Combining our NASA-Sloan Atlas sample with samples of nearby galaxies with broad H{alpha} emission, we find no dependence of variability properties with black hole mass. Our PTF work demonstrates the promise of long-term optical variability searches in low-mass galaxies for finding AGNs missed by other selection techniques.2020ApJ...896...10Bhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/896/10CatalogResearchIsServedByTAP VizieR generic serviceIsServedByConesearch servicerelated-toV/147 : The SDSS Photometric Catalogue, Release 12 (Alam+, 2015)J/AcA/50/421 : OGLE-II DIA BUL_SC1 field (Wozniak, 2000)J/MNRAS/375/989 : Quasar variability (Wold+, 2007)J/ApJ/670/92 : New sample of low-mass black holes in AGN (Greene+, 2007)J/ApJ/698/895 : Variations in QSOs optical flux (Kelly+, 2009)J/ApJ/728/26 : QSO selection based on photometric variability (Macleod+, 2011)J/AJ/142/153 : Precision spectrophotometry at the level of 0.1% (Yan, 2011)J/ApJ/753/22 : Swift/UVOT observations of SN 2011fe (Brown+, 2012)J/ApJ/775/116 : z<0.06 active black hole galaxies from SDSS-DR8 (Reines+, 2013)J/ApJ/793/38 : Palomar Transient Factory photometric obs. (Arcavi+, 2014)J/ApJ/813/82 : z<0.06 broad-line AGN emission-line measures (Reines+, 2015)J/ApJ/830/13 : Host-galaxy NUV-NIR data of superluminous SNe (Perley+, 2016)J/ApJ/858/118 : Kinematic data of 3 nearby low-mass galaxies (Nguyen+, 2018)J/ApJ/872/198 : LCs of tidal disruption flare AT2018zr (van Velzen+, 2019)J/ApJS/243/21 : A complete sample of broad-line AGN from SDSS-DR7 (Liu+, 2019)http://www.nsatlas.org/ : NASA-Sloan Atlas home pagehttps://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/896/10https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/896/10http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/896/10https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/896/10https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/896/10http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/896/10GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapCone search capability for table J/ApJ/896/10/table3 (Low-mass galaxies with AGN-like variability)https://vizier.cds.unistra.fr/viz-bin/conesearch/J/ApJ/896/10/table3?https://vizier.iucaa.in/viz-bin/conesearch/J/ApJ/896/10/table3?http://vizieridia.saao.ac.za/viz-bin/conesearch/J/ApJ/896/10/table3?GETtext/xml+votable180.050000true4.2982529.48090.0055555555555555566/554 2221 2276 2708 4181 4352 4444 4447 4490-4491 4577 4654 4710 4774 4807 4817 4854 4991 5009 5011 5148 5364 5587 5646 5657 5945 5996 6099 6222 6451 6996 7197 7240 7298 7308 7355 7684 8204 8215 8226 8270 8277 8359 8428 8495 8499 8520 8524 8526 8545 8547 8551 8553 8558 8564 8567 8571 8575 8606 8621 8632 8648 8700 8866 8947 8992 9216-9217 9219 9232 9241-9242 9245 9256 9264 9294 9333 9343 9363 9389 9396 9402 9409 9433 9443 9446 9465 9467-9468 9470-9471 9514 9600 9660 9741 9749 9751 9813 9832 9841 9849 9856 9884 9909 9932 9954 9968 10026 10084 10095 10194 10222 10246 10350 10378 10399-10400 10442 10456 10511 10547 10660 10750 10761 10775 10808 10839 10896 10908 10953 10963 11008 11064 11217 11219 11266 11303 11319 11334 11400 11435 11456 11591 11779 11791 11942 12123 13903 15351 17749-17750 17755 17768 17842 18006 18019 18032 18071 18302 18416 18779 18782 18840 19087 19100 19411 20072 20149 20269 20324-20325 20358 20371 22355 22361 22746 23043 25974 26077 26310 26342 26349 26362 26457 26501 26560 27348 27384 27566 27669 27719 27742 27771 27858 27860 27866 28064 28071 28148 28159 28425 28627 28654 31346 31448 31457 31470 31478 31636 31649 31695 31698 32421 32511 36342https://cdsarc.cds.unistra.fr/viz-bin/moc/J/ApJ/896/10?format=asciiOpticaldefaultJ/ApJ/896/10/table3Low-mass galaxies with AGN-like variabilitySimbadNameSimbad column added by the CDSmeta.idcharnullablerecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintObjIDIdentifier, NASA-Sloan Atlas (NSA) version 0meta.id;meta.maincharRAJ2000Right Ascension, decimal degree (J2000)degpos.eq.ra;meta.mainDEJ2000Declination, decimal degree (J2000)degpos.eq.dec;meta.mainzspec[-0.0018/0.055] SDSS spectroscopic redshiftsrc.redshiftfloatlogMs[6.4/10] Log of stellar masslog(solMass)phys.massfloatNp[20/1589] Number of pointsmeta.numberintBaseline[59.93/2144.17] Baselinedtime.intervalfloatRmagMed[15.3/21] Median R band magnitudemagphot.mag;em.opt.RfloatStd[0.01/0.3] Standard deviation in light curvemagstat.stdev;phot.magfloatSigVar[2/167] Significance, light curve is variablestat.fit.goodnessfloatSigQSO[2/12] Significance, light curve is an AGNstat.fit.goodnessfloatSigNoQSO[0/9] Significance, light curve is a false alarmstat.fit.goodnessfloatSloanDisplay the online SDSS-DR14 data for the nearest objectmeta.ref.urlcharNEDNED column added by the CDSmeta.ref.urlchar