Please use this identifier to cite or link to this item: http://hdl.handle.net/2381/32892
Title: SPACE TELESCOPE AND OPTICAL REVERBERATION MAPPING PROJECT. I. ULTRAVIOLET OBSERVATIONS OF THE SEYFERT 1 GALAXY NGC 5548 WITH THE COSMIC ORIGINS SPECTROGRAPH ON HUBBLE SPACE TELESCOPE
Authors: De Rosa, G.
Peterson, B. M.
Ely, J.
Kriss, G. A.
Crenshaw, D. M.
Horne, K.
Korista, K. T.
Netzer, H.
Pogge, R. W.
Arevalo, P.
Barth, A. J.
Bentz, M. C.
Brandt, W. N.
Breeveld, A. A.
Brewer, B. J.
Bonta, E. D.
De Lorenzo-Caceres, A.
Denney, K. D.
Dietrich, M.
Edelson, R.
Evans, P. A.
Fausnaugh, M. M.
Gehrels, N.
Gelbord, J. M.
Goad, Michael R.
Grier, C. J.
Grupe, D.
Hall, P. B.
Kaastra, J.
Kelly, B. C.
Kennea, J. A.
Kochanek, C. S.
Lira, P.
Mathur, S.
McHardy, I. M.
Nousek, J. A.
Pancoast, A.
Papadakis, I.
Pei, L.
Schimoia, J. S.
Siegel, M.
Starkey, D.
Treu, T.
Uttley, P.
Vaughan, S.
Vestergaard, M.
Villforth, C.
Yan, H.
Young, S.
Zu, Y.
First Published: 12-Jun-2015
Publisher: IOP Publishing LTD
Citation: Astrophysical Journal, 2015, 806 (1), 128
Abstract: We describe the first results from a six-month long reverberation-mapping experiment in the ultraviolet based on 171 observations of the Seyfert 1 galaxy NGC 5548 with the Cosmic Origins Spectrograph on the Hubble Space Telescope. Significant correlated variability is found in the continuum and broad emission lines, with amplitudes ranging from ~30% to a factor of two in the emission lines and a factor of three in the continuum. The variations of all the strong emission lines lag behind those of the continuum, with He ii λ1640 lagging behind the continuum by ~2.5 days and Lyα λ1215, C iv λ1550, and Si iv λ1400 lagging by ~5–6 days. The relationship between the continuum and emission lines is complex. In particular, during the second half of the campaign, all emission-line lags increased by a factor of 1.3–2 and differences appear in the detailed structure of the continuum and emission-line light curves. Velocity-resolved cross-correlation analysis shows coherent structure in lag versus line of sight velocity for the emission lines; the high-velocity wings of C iv respond to continuum variations more rapidly than the line core, probably indicating higher velocity broad-line region clouds at smaller distances from the central engine. The velocity-dependent response of Lyα, however, is more complex and will require further analysis.
DOI Link: 10.1088/0004-637X/806/1/128
ISSN: 0004-637X
eISSN: 1538-4357
Links: http://iopscience.iop.org/0004-637X/806/1/128/
http://hdl.handle.net/2381/32892
Version: Publisher Version
Status: Peer-reviewed
Type: Journal Article
Rights: Copyright © The American Astronomical Society. All rights reserved. Deposited with reference to the publisher’s archiving policy available on the SHERPA/RoMEO website.
Appears in Collections:Published Articles, Dept. of Physics and Astronomy

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