J/ApJ/958/195ivo://CDS.VizieR/J/ApJ/958/195doi:10.26093/cds/vizier/ba-xy-63CDSCackett E.M.Gelbord J.Barth A.J.De Rosa G.Edelson R.Goad M.R.,Homayouni Y.Horne K.Kara E.A.Kriss G.A.Korista K.T.Landt H.,Plesha R.Arav N.Bentz M.C.Boizelle B.D.Dalla Bonta E.,Dehghanian M.Donnan F.Du PuFerland G.J.Fian C.Filippenko A.V.,Gonzalez Buitrago D.H.Grier C.J.Hall P.B.Hu C.Ilic D.Kaastra J.,Kaspi S.Kochanek C.S.Kovacevic A.B.Kynoch D.Li Y.-R.McLane J.N.,Mehdipour M.Miller J.A.Montano J.Netzer H.Panagiotou C.,Partington E.Popovic L. CProga D.Rogantini D.Sanmartim D.,Siebert M.R.Storchi-Bergmann T.Vestergaard M.Wang J.-M.Waters T.,Zaidouni F.2026-07-02T12:01:00Z2026-02-23T10:46:31ZCDS support team

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

cds-question@unistra.fractive-galactic-nucleivisible-astronomybroad-band-photometryultraviolet-astronomyx-ray-sourcesThe AGN STORM 2 campaign is a large, multiwavelength reverberation mapping project designed to trace out the structure of Mrk 817 from the inner accretion disk to the broad emission line region and out to the dusty torus. As part of this campaign, Swift performed daily monitoring of Mrk 817 for approximately 15 months, obtaining observations in X-rays and six UV/optical filters. The X-ray monitoring shows that Mrk 817 was in a significantly fainter state than in previous observations, with only a brief flare where it reached prior flux levels. The X-ray spectrum is heavily obscured. The UV/optical light curves show significant variability throughout the campaign and are well correlated with one another, but uncorrelated with the X-rays. Combining the Swift UV/optical light curves with Hubble Space Telescope UV continuum light curves, we measure interband continuum lags, {tau}({lambda}), that increase with increasing wavelength roughly following {tau}({lambda}){\prop}{lambda}^4/3^, the dependence expected for a geometrically thin, optically thick, centrally illuminated disk. Modeling of the light curves reveals a period at the beginning of the campaign where the response of the continuum is suppressed compared to later in the light curve-the light curves are not simple shifted and scaled versions of each other. The interval of suppressed response corresponds to a period of high UV line and X-ray absorption, and reduced emission line variability amplitudes. We suggest that this indicates a significant contribution to the continuum from the broad-line region gas that sees an absorbed ionizing continuum.2023ApJ...958..195Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/ApJ/958/195CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/ApJ/613/682 : AGN masses and broad-line region sizes (Peterson+, 2004)J/MNRAS/397/1177 : Swift-XRT observations of GRBs (Evans+, 2009)J/ApJ/806/128 : Space telescope RM project. I. NGC5548 (De Rosa+, 2015)J/ApJ/806/129 : Space telescope RM project. II. Swift data (Edelson+, 2015)J/ApJ/821/56 : Space telescope RM project. III. LCs (Fausnaugh+, 2016)J/ApJ/840/41 : X-ray/UV Swift monitoring of NGC 4151 (Edelson+, 2017)J/ApJ/836/186 : Continuum-band lags in SDSS QSOs from PS1 (Jiang+, 2017)J/ApJ/837/131 : Space telescope RM project. V. NGC5548 sp. (Pei+, 2017)J/ApJ/854/107 : Light curves of 2 Seyfert 1 galaxies (Fausnaugh+, 2018)J/ApJ/862/123 : griz light curves of 15 DES quasars (Mudd+, 2018)J/ApJ/870/123 : Swift optical & UV flux of four AGNs (Edelson+, 2019)J/ApJ/896/1 : SEAMBHs. XI. Mrk 142 X-ray to optical LCs (Cackett+, 2020)J/A+A/659/A13 : PG 2130+099 narrowband light curves (Fian+, 2022)J/ApJ/948/85 : AGN STORM 2. II. HST/COS obs. of Mrk817 (Homayouni+, 2023)J/ApJ/947/2 : AGN STORM 2. III. NICER obs. of Mrk 817 (Partington+, 2023)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/ApJ/958/195https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/ApJ/958/195http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/ApJ/958/195https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/ApJ/958/195https://vizier.iucaa.in/viz-bin/votable?-source=J/ApJ/958/195http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/ApJ/958/195GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapX-rayUVOpticaldefaultJ/ApJ/958/195/table1Swift photometry of Mrk 817recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintHJD[9176.5/9692.2] Heliocentric Julian Date; HJD-2450000dtime.epochdoubleFiltFilter/Band (1)meta.code;instr.filtercharFlux[6.8/53.5]? Swift/UVOT Flux in Filt in 10^-15^erg/cm^2^/s/{AA}1e-15cW.m**-2.nm**-1phot.fluxfloatnullablee_Flux[0.1/1.7]? Uncertainty in Flux1e-15cW.m**-2.nm**-1stat.error;phot.fluxfloatnullableCRate[0.007/0.6]? X-ray rate in bandct/sphot.count;em.X-rayfloatnullablee_CRate[0.003/0.06]? Uncertainty in CRatect/sstat.error;phot.count;em.X-rayfloatnullable