J/ApJ/909/159ivo://CDS.VizieR/J/ApJ/909/159doi:10.26093/cds/vizier.19090159CDSCannizzaro G.Jonker P.G.Mata-Sanchez D.2022-09-14T06:11:49Z2022-09-12T11:53:53ZCDS support team

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

cds-question@unistra.frgalaxiesinfrared-sourcesvisible-astronomyspectroscopyactive-galactic-nucleiWe present results of spectroscopic monitoring observations of the ultraluminous infrared galaxy F01004-2237. This galaxy was observed to undergo changes in its optical spectrum, detected by comparing a spectrum from 2015 with one from 2000. These changes were coincident with photometric brightening. The main changes detected in the optical spectrum are enhanced HeII{lambda}4686 emission and the appearance of HeI{lambda}3898,{lambda}5876 emission lines. The favored interpretation of these changes was that of a tidal disruption event (TDE) happening in 2010. However, subsequent work suggested that these changes are caused by another hitherto unknown effect related to variations in the accretion rate in the active galactic nucleus (AGN). Our optical spectroscopic monitoring observations show that the evolution of the He lines is in line with the evolution seen in TDEs and opposite of what is observed from reverberation-mapping studies of AGNs, renewing the discussion of the interpretation of the flare as a TDE.2021ApJ...909..159Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/909/159CatalogResearchIsServedByTAP VizieR generic servicerelated-toB/hst : HST Archived Exposures Catalog (STScI, 2007)II/338 : IRAS PSC/FSC Combined Catalogue (Abrahamyan+ 2015)J/ApJ/613/682 : AGN masses & broad-line region sizes (Peterson+, 2004)J/MNRAS/398/109 : Imperial IRAS-FSC redshift catalogue (IIFSCz) (Wang+, 2009)J/ApJS/182/628 : Spitzer quasar and ULIRG evolution study (Veilleux+, 2009)J/ApJ/696/870 : Catalina Real-time Transient Survey (CRTS) (Drake+, 2009)J/ApJ/698/1682 : Most luminous dusty galaxies (Weedman+, 2009)J/ApJ/709/884 : Role of starburst-AGNs in LIRG mergers (Yuan+, 2010)J/ApJ/730/19 : IR spectra and SEDs for starbursts and AGNs (Sargsyan+, 2011)J/ApJ/793/38 : Palomar Transient Factory photometric obs. (Arcavi+, 2014)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/909/159https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/909/159http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/909/159https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/909/159https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/909/159http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/909/159GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticalInfrareddefaultJ/ApJ/909/159/fig1The sequence of spectra under study in this paperrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintDateDate of the observationtime.epochnullableindexedTelTelescope/instrument used (1)instr.setupcharlambda[3177/9057.2] Wavelength in Angstroms (2)0.1nmem.wlfloatFlux[-1.49/14.54] Normalized fluxphot.flux;arith.ratiofloate_Flux[0.007/2.2] Uncertainty in Fluxstat.error;phot.fluxdouble