J/A+A/609/A71ivo://CDS.VizieR/J/A+A/609/A71doi:10.26093/cds/vizier.36090071CDSCourbin F.Bonvin V.Buckley-Geer E.Fassnacht C.D.Frieman J.Lin H.,Marshall P.J.Suyu S.H.Treu T.Anguita T.Motta V.Meylan G.Paic E.,Tewes M.Agnello A.Chao D.C.-Y.Chijani M.Gilman D.Rojas K.,Williams P.Hempel A.Kim S.Lachaume R.Rabus M.Abbott T.M.C.,Allam S.Annis J.Banerji M.Bechtol K.Benoit-Levy A.Brooks D.,Burke D.L.Rosell A.CarneroKind M.CarrascoCarretero J.,D'Andrea C.B.Costa L.N.daDavis C.DePoy D.L.Desai S.Flaugher B.,Fosalba P.Garcia-Bellido J.Gaztanaga E.Goldstein D.A.Gruen D.,Gruendl R.A.Gschwend J.Gutierrez G.Honscheid K.James D.J.Kuehn K.,Kuhlmann S.Kuropatkin N.Lahav O.Lima M.Maia M.A.G.March M.,Marshall J.L.McMahon R.G.Menanteau F.Miquel R.Nord B.Plazas A.A.,Sanchez E.Scarpine V.Schindler R.Schubnell M.Sevilla-Noarbe I.,Smith M.Soares-Santos M.Sobreira F.Suchyta E.Tarle G.Tucker D.L.,Walker A.R.Wester W.2018-03-12T08:32:38Z2018-01-09T08:19:57ZCDS support team

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

cds-question@unistra.frquasarsgravitational-lensingphotometryWe present time-delay measurements for the new quadruply imaged quasar DES J0408-5354, the first quadruply imaged quasar found in the Dark Energy Survey (DES). Our result is made possible by implementing a new observational strategy using almost daily observations with the MPIA 2.2m telescope at La Silla observatory and deep exposures reaching a signal-to-noise ratio of about 1000 per quasar image. This data quality allows us to catch small photometric variations (a few mmag rms) of the quasar, acting on temporal scales much shorter than microlensing, hence making the time delay measurement very robust against microlensing. In only 7 months we measure very accurately one of the time delays in DES J0408-5354: Dt(AB)=-112.1+/-2.1-days (1.8%) using only the MPIA 2.2m data. In combination with data taken with the 1.2m Euler Swiss telescope, we also measure two delays involving the D component of the system Dt(AD)=-155.5+/-12.8-days (8.2%) and Dt(BD)=-42.4+/-17.6-days (41%), where all the error bars include systematics. Turning these time delays into cosmological constraints will require deep HST imaging or ground-based Adaptive Optics (AO), and information on the velocity field of the lensing galaxy.2018A&A...609A..71Chttps://cdsarc.cds.unistra.fr/viz-bin/cat/J/A+A/609/A71CatalogResearchIsServedByTAP VizieR generic servicerelated-toJ/A+A/488/481 : Time delays and H0 from WFI J2033-4723 (Vuissoz+, 2008)J/A+A/536/A53 : R-band light curves of HE 0435-1223 (Courbin+, 2011)J/A+A/553/A121 : 2 lensed quasars light curves (Eulaers+, 2013)J/A+A/556/A22 : R-band light curves of RX J1131-1231 (Tewes+, 2013)J/A+A/557/A44 : The doubly lensed quasar SDSS J1001+5027 (Rathna Kumar+, 2013)https://cds.unistra.fr/vizier-org/licences_vizier.htmlhttps://vizier.cds.unistra.fr/viz-bin/VizieR-2?-source=J/A+A/609/A71https://vizier.iucaa.in/viz-bin/VizieR-2?-source=J/A+A/609/A71http://vizieridia.saao.ac.za/viz-bin/VizieR-2?-source=J/A+A/609/A71https://vizier.cds.unistra.fr/viz-bin/votable?-source=J/A+A/609/A71https://vizier.iucaa.in/viz-bin/votable?-source=J/A+A/609/A71http://vizieridia.saao.ac.za/viz-bin/votable?-source=J/A+A/609/A71GETtext/xml+votablehttps://tapvizier.cds.unistra.fr/TAPVizieR/tapOpticaldefaultJ/A+A/609/A71/figure3R-band light curves of DES J0408-5359recnoRecord number assigned by the VizieR team. Should Not be used for identification.meta.recordintMHJDModified Julian Date (heliocentric)dtime.epochdoublemagARelative magnitude of quasar image Amagphot.mag;em.opt.Rdoublee_magAMagnitude uncertainty of quasar image Amagstat.errordoublemagBRelative magnitude of quasar image Bmagphot.mag;em.opt.Rdoublee_magBMagnitude uncertainty of quasar image Bmagstat.errordoublemagDRelative magnitude of quasar image Dmagphot.mag;em.opt.Rdoublee_magDMagnitude uncertainty of quasar image Dmagstat.errordoubleTelName of the instrument usedmaginstr.setupchar