J/ApJ/898/161ivo://CDS.VizieR/J/ApJ/898/161doi:10.26093/cds/vizier.18980161CDSHoloien T.W.-S.Auchettl K.Tucker M.A.Shappee B.J.Patel S.G.,Miller-Jones J.C.A.Mockler B.Groenewald D.N.Hinkle J.T.Brown J.S.,Kochanek C.S.Stanek K.Z.Chen P.Dong S.Prieto J.L.Thompson T.A.,Beaton R.L.Connor T.Cowperthwaite P.S.Dahmen L.French K.D.,Morrell N.Buckley D.A.H.Gromadzki M.Roy R.Coulter D.A.,Dimitriadis G.Foley R.J.Kilpatrick C.D.Piro A.L.Rojas-Bravo C.,Siebert M.R.van Velzen S.2022-03-16T12:55:51Z2021-12-17T08:27:32ZCDS support team

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

cds-question@unistra.frultraviolet-photometryinfrared-photometryvisible-astronomybroad-band-photometryspectroscopyWe present nearly 500 days of observations of the tidal disruption event (TDE) ASASSN-18pg, spanning from 54 days before peak light to 441 days after peak light. Our data set includes X-ray, UV, and optical photometry, optical spectroscopy, radio observations, and the first published spectropolarimetric observations of a TDE. ASASSN-18pg was discovered on 2018 July 11 by the All-Sky Automated Survey for Supernovae (ASAS-SN) at a distance of d=78.6Mpc; with a peak UV magnitude of m~14, it is both one of the nearest and brightest TDEs discovered to-date. The photometric data allow us to track both the rise to peak and the long-term evolution of the TDE. ASASSN-18pg peaked at a luminosity of L~2.4x10^44^erg/s, and its late-time evolution is shallower than a flux {propto}t^-5/3^ power-law model, similar to what has been seen in other TDEs. ASASSN-18pg exhibited Balmer lines and spectroscopic features consistent with Bowen fluorescence prior to peak, which remained detectable for roughly 225days after peak. Analysis of the two-component H{alpha} profile indicates that, if they are the result of reprocessing of emission from the accretion disk, the different spectroscopic lines may be coming from regions between ~10 and ~60 lt-days from the black hole. No X-ray emission is detected from the TDE, and there is no evidence of a jet or strong outflow detected in the radio. Our spectropolarimetric observations indicate that the projected emission region is likely not significantly aspherical, with the projected emission region having an axis ratio of >~0.65.2020ApJ...898..161Hhttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/898/161CatalogResearchIsServedByTAP VizieR generic servicerelated-toII/226 : Stellar polarization catalogs agglomeration (Heiles, 2000)J/ApJ/613/682 : AGN central masses (Peterson+, 2004)J/MNRAS/383/445 : Radial velocities in Norma cluster (A3627) (Woudt+, 2008)J/ApJ/793/38 : Palomar Transient Factory photometric obs. (Arcavi+, 2014)J/ApJ/788/48 : X-ray through NIR photometry of NGC 2617 (Shappee+, 2014)J/A+A/594/A116 : HI4PI spectra and column density maps (HI4PI team+, 2016)J/MNRAS/463/3813 : ASASSN-15oi UBVI M2W1W2 light curves (Holoien+, 2016)J/MNRAS/455/2918 : Phot. & line luminosities for ASASSN-14li (Holoien+, 2016)J/ApJ/844/46 : Phot. of the transient event iPTF16fnl (Blagorodnova+, 2017)J/ApJ/873/92 : Opt. & UV evolution of iPTF15af (Blagorodnova+, 2019)J/ApJ/883/111 : UV-Opt LCs of ASASSN-19bt detected by TESS (Holoien+, 2019)J/ApJ/880/120 : Phot. of the tidal disruption event PS18kh (Holoien+, 2019)J/ApJ/872/198 : UV-Opt LC of AT2018zr (van Velzen+, 2019)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/898/161https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/898/161http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/898/161https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/898/161https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/898/161http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/898/161GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapUVOpticalInfrareddefaultJ/ApJ/898/161/table3Host-subtracted photometry of ASASSN-18pgFiltPhotometric Filter (ugri, UBVM2W1W2)meta.notecharrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMJDMJD or lower MJD range (1)dtime.epochdoubleMJD2? Upper MJD range (1)dtime.epochdoublenullablel_magThe 3{sigma} upper detection limit on magmeta.code.errorcharmag[13.8/18.4] Apparent AB magnitude in Filt (2)magphot.magfloate_mag[0.02/0.5]? Lower Uncertainty on the Magnitudemagstat.error;phot.magfloatnullableE_mag[0.02/0.5]? Upper Uncertainty on the Magnitudemagstat.error;stat.maxfloatnullableTelTelescope or Observatory used (3)meta.id;instr.telcharJ/ApJ/898/161/fig3Spectroscopic evolution of ASASSN-18pg spanning from 26days prior to peak through 407days after peakrecnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintTelTelescope/Instrument identifier (1)meta.id;meta.maincharDateObservation datetime.epoch;obsnullableindexedlambda[2958.9/9753.1] Wavelength in Angstrom units0.1nmem.wlfloatFlux[-4.84e-15/1.4e-13] Flux density in erg/s/cm^2^/{AA} unitscW.m**-2.nm**-1meta.unit;phot.flux.densitydouble