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Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum

Kriss, G. A. and Adams, S. M. (2019) Space Telescope and Optical Reverberation Mapping Project. VIII. Time Variability of Emission and Absorption in NGC 5548 Based on Modeling the Ultraviolet Spectrum. Astrophysical Journal, 881 (2). Art. No. 153. ISSN 1538-4357.

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We model the ultraviolet spectra of the Seyfert 1 galaxy NGC 5548 obtained with the Hubble Space Telescope during the 6 month reverberation mapping campaign in 2014. Our model of the emission from NGC 5548 corrects for overlying absorption and deblends the individual emission lines. Using the modeled spectra, we measure the response to continuum variations for the deblended and absorption-corrected individual broad emission lines, the velocity-dependent profiles of Lyα and C iv, and the narrow and broad intrinsic absorption features. We find that the time lags for the corrected emission lines are comparable to those for the original data. The velocity-binned lag profiles of Lyα and C iv have a double-peaked structure indicative of a truncated Keplerian disk. The narrow absorption lines show a delayed response to continuum variations corresponding to recombination in gas with a density of ~10^5 cm^(−3). The high-ionization narrow absorption lines decorrelate from continuum variations during the same period as the broad emission lines. Analyzing the response of these absorption lines during this period shows that the ionizing flux is diminished in strength relative to the far-ultraviolet continuum. The broad absorption lines associated with the X-ray obscurer decrease in strength during this same time interval. The appearance of X-ray obscuration in ~2012 corresponds with an increase in the luminosity of NGC 5548 following an extended low state. We suggest that the obscurer is a disk wind triggered by the brightening of NGC 5548 following the decrease in size of the broad-line region during the preceding low-luminosity state.

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Adams, S. M.0000-0001-5855-5939
Additional Information:© 2019 The American Astronomical Society. Original content from this work may be used under the terms of the Creative Commons Attribution 3.0 licence. Any further distribution of this work must maintain attribution to the author(s) and the title of the work, journal citation and DOI. Received 2019 March 29; revised 2019 June 27; accepted 2019 July 6; published 2019 August 22. We thank R. Plesha for formatting and posting the high-level data products in MAST. Support for HST program number GO-13330 was provided by NASA through a grant from the Space Telescope Science Institute, which is operated by the Association of Universities for Research in Astronomy, Inc., under NASA contract NAS5-26555. M.M.F., G.D.R., B.M.P., C.J.G., and R.W.P. are grateful for the support of the National Science Foundation (NSF) through grant AST-1008882 to The Ohio State University. A.J.B. and L.P. have been supported by NSF grant AST-1412693. E.M.C., E.D.B., L.M., and A.P. acknowledge support from Padua University through grants DOR1699945/16, DOR1715817/17, DOR1885254/18, and BIRD164402/16. M.C. Bentz gratefully acknowledges support through NSF CAREER grant AST-1253702 to Georgia State University. S.B. was supported by NASA through Chandra award no. AR7-18013X issued by the Chandra X-ray Observatory Center, operated by the Smithsonian Astrophysical Observatory for NASA under contract NAS8-03060. S.B. was also partially supported by grant HST-AR-13240.009. M.C. Bottorff acknowledges HHMI for support through an undergraduate science education grant to Southwestern University. K.D.D. is supported by an NSF Fellowship awarded under grant AST-1302093. R.E. gratefully acknowledges support from NASA under awards NNX13AC26G, NNX13AC63G, and NNX13AE99G, and ADAP award 80NSSC17K0126. G.J.F. and M.D. thank NSF (1816537), NASA (ATP 17-0141), and STScI (HST-AR-13914, HST-AR-15018) for their support, and the Huffaker scholarship for funding related travel. B.D.M. acknowledges support from the Polish National Science Center grant Polonez 2016/21/P/ST9/04025. J.M.G. gratefully acknowledges support from NASA under award NNH13CH61C. P.B.H. is supported by NSERC. K.H. acknowledges support from the UK Science and Technology Facilities Council through grant ST/J001651/1. M.I. acknowledges support from the National Research Foundation of Korea (NRF) grant, No. 2017R1A3A3001362. M.K. was supported by the National Research Foundation of Korea (NRF) grant funded by the Korean government (MSIT) (No. 2017R1C1B2002879). M.D.J. acknowledges NSF grant AST-0618209. SRON is financially supported by NWO, the Netherlands Organization for Scientific Research. B.C.K. is partially supported by the UC Center for Galaxy Evolution. C.S.K. acknowledges the support of NSF grants AST-1814440 and AST-1515876. D.C.L. acknowledges support from NSF grants AST-1009571 and AST-1210311. P.L. acknowledges support from Fondecyt grant #1120328. A.P. acknowledges support from a NSF graduate fellowship and a UCSB Dean’s Fellowship. C.S. acknowledges support from NOVA, the Nederlandse Onderzoekschool voor Astronomie. J.S.S. acknowledges CNPq, National Council for Scientific and Technological Development (Brazil) for partial 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 Foundation in the form of a Packard Research Fellowship to T.T. Support for A.V.F.’s group at U.C. Berkeley is provided by the TABASGO Foundation, the Christopher R. Redlich Fund, and the Miller Institute for Basic Research in Science (U.C. Berkeley). M.V. and J.J.J. gratefully acknowledge support from the Danish Council for Independent Research via grant no. DFF 4002-00275. J.-H.W. acknowledges support by the National Research Foundation of Korea (NRF) grant funded by the Korean government (No. 2010-0027910). This research has made use of the NASA/IPAC Extragalactic Database (NED), which is operated by the Jet Propulsion Laboratory, California Institute of Technology, under contract with the National Aeronautics and Space Administration.
Funding AgencyGrant Number
Padua UniversityDOR1699945/16
Padua UniversityDOR1715817/17
Padua UniversityDOR1885254/18
Padua UniversityBIRD164402/16
NASA Hubble FellowshipHST-AR-13240.009
Howard Hughes Medical Institute (HHMI)UNSPECIFIED
NASAATP 17-0141
NASA Hubble FellowshipHST-AR-13914
NASA Hubble FellowshipHST-AR-15018
Huffaker ScholarshipUNSPECIFIED
National Science Centre (Poland)2016/21/P/ST9/04025
Natural Sciences and Engineering Research Council of Canada (NSERC)UNSPECIFIED
Science and Technology Facilities Council (STFC)ST/J001651/1
National Research Foundation of Korea2017R1A3A3001362
National Research Foundation of Korea2017R1C1B2002879
Nederlandse Organisatie voor Wetenschappelijk Onderzoek (NWO)UNSPECIFIED
Southern California Center for Galaxy EvolutionUNSPECIFIED
Fondo Nacional de Desarrollo Científico y Tecnológico (FONDECYT)1120328
NSF Graduate Research FellowshipUNSPECIFIED
University of California, Santa BarbaraUNSPECIFIED
Nederlandse Onderzoekschool Voor Astronomie (NOVA)UNSPECIFIED
Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)UNSPECIFIED
David and Lucile Packard FoundationUNSPECIFIED
Christopher R. Redlich FundUNSPECIFIED
Miller Institute for Basic Research in ScienceUNSPECIFIED
Danish Council for Independent ResearchDFF 4002-00275
National Research Foundation of Korea2010-0027910
Subject Keywords:galaxies: active — galaxies: individual (NGC 5548)— galaxies: nuclei — galaxies: Seyfert
Issue or Number:2
Record Number:CaltechAUTHORS:20190814-074022037
Persistent URL:
Official Citation:G. A. Kriss et al 2019 ApJ 881 153
Usage Policy:No commercial reproduction, distribution, display or performance rights in this work are provided.
ID Code:97867
Deposited By: Tony Diaz
Deposited On:14 Aug 2019 16:48
Last Modified:03 Oct 2019 21:35

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