Space Telescope and Optical Reverberation Mapping Project. III. Optical Continuum Emission and Broad-Band Time Delays in NGC 5548

The LBT is an international collaboration among institutionsin the United States, Italy and Germany. LBT Corporationpartners are: The Ohio State University, and The ResearchCorporation, on behalf of The University of Notre Dame, Universityof Minnesota and University of Virginia; The Universityof Arizona on behalf of the Arizona university system;Istituto Nazionale di Astrofisica, Italy; LBT Beteiligungsgesellschaft,Germany, representing the Max-Planck Society, theAstrophysical Institute Potsdam, and Heidelberg University.This paper used data obtained with the MODS spectrographsbuilt with funding from National Science Foundation (NSF)grant AST-9987045 and the NSF Telescope System InstrumentationProgram (TSIP), with additional funds from the OhioBoard of Regents and the Ohio State University Office of Research.This paper made use of the modsIDL spectral datareduction pipeline developed in part with funds provided byNSF Grant AST - 1108693.The Liverpool Telescope is operated on the island of LaPalma by Liverpool John Moores University in the SpanishObservatorio del Roque de los Muchachos of the Instituto deAstrofisica de Canarias with financial support from the UKScience and Technology Facilities Council.KAIT and its ongoing operation were made possible by donationsfrom Sun Microsystems, Inc., the Hewlett-PackardCompany, AutoScope Corporation, Lick Observatory, theNSF, the University of California, the Sylvia and Jim KatzmanFoundation, and the TABASGO Foundation. Research atLick Observatory is partially supported by a generous gift fromGoogle.Support for HST program number GO-13330 was providedby NASA through a grant from the Space Telescope ScienceInstitute, which is operated by the Association of Universitiesfor Research in Astronomy, Inc., under NASA contractNAS5-26555. M.M.F., G.D.R., B.M.P., C.J.G., and R.W.P.are grateful for the support of the NSF through grant AST-1008882 to The Ohio State University. A.J.B. and L.P. havebeen supported by NSF grant AST-1412693. A.V.F. and W.-K.Z. are grateful for financial assistance from NSF grant AST-1211916, the TABASGO Foundation, and the Christopher R.Redlich Fund. M.C. Bentz gratefully acknowledges supportthrough NSF CAREER grant AST-1253702 to Georgia StateUniversity. M.C. Bottorff acknowledges HHMI for supportthrough an undergraduate science education grant to SouthwesternUniversity. K.D.D. is supported by an NSF Fellowshipawarded under grant AST-1302093. R.E. gratefully acknowledgessupport from NASA under awards NNX13AC26G,NNX13AC63G, and NNX13AE99G. J.M.G. gratefully acknowledgessupport from NASA under award NNH13CH61C.P.B.H. is supported by NSERC. M.I. acknowledges supportfrom the Creative Initiative program, No. 2008-0060544, ofthe National Research Foundation of Korea (NRFK) fundedby the Korean government (MSIP). M.D.J. acknowledges NSFgrant AST-0618209 used for obtaining the 0.91 m telescope atWMO. SRON is financially supported by NWO, the NetherlandsOrganization for Scientific Research. B.C.K. is partiallysupported by the UC Center for Galaxy Evolution. C.S.K. acknowledgesthe support of NSF grant AST-1009756. D.C.L.acknowledges support from NSF grants AST-1009571 andAST-1210311, under which part of this research (photometricobservations collected at MLO) was carried out. We thankNhieu Duong, Harish Khandrika, Richard Mellinger, J. ChuckHorst, Steven Armen, and Eddie Garcia for assistance with theMLO observations. P.L. acknowledges support from Fondecytgrant #1120328. A.P. acknowledges support from a NSF graduatefellowship, a UCSB Dean’s Fellowship, and a NASA EinsteinFellowship. J.S.S. acknowledges CNPq, National Councilfor Scientific and Technological Development (Brazil) forpartial support and The Ohio State University for warm hospitality.T.T. has been supported by NSF grant AST-1412315.T.T. and B.C.K. acknowledge support from the Packard Foundationin the form of a Packard Research Fellowship to T.T.;also, T.T. thanks the American Academy in Rome and the Observatoryof Monteporzio Catone for kind hospitality. TheDark Cosmology Centre is funded by the Danish NationalResearch Foundation. M.V. gratefully acknowledges supportfrom the Danish Council for Independent Research via grantno. DFF–4002-00275. J.-H.W. acknowledges support by theNational Research Foundation of Korea (NRF) grant fundedby the Korean government (No. 2010-0027910). E.D.B. issupported by Padua University through grants 60A02-5857/13,60A02-5833/14, 60A02-4434/15, and CPDA133894. K.H. acknowledgessupport from STFC grant ST/M001296/1. S.A.K.thanks Dr. I. A. Rakhimov, the Director of Svetloe Observatory,for his support and hospitality.This research has made use of the NASA/IPAC ExtragalacticDatabase (NED), which is operated by the Jet PropulsionLaboratory, California Institute of Technology, under contractwith NASA.