- Starkey, D;
- Horne, Keith;
- Fausnaugh, MM;
- Peterson, BM;
- Bentz, MC;
- Kochanek, CS;
- Denney, KD;
- Edelson, R;
- Goad, MR;
- De Rosa, G;
- Anderson, MD;
- Arévalo, P;
- Barth, AJ;
- Bazhaw, C;
- Borman, GA;
- Boroson, TA;
- Bottorff, MC;
- Brandt, WN;
- Breeveld, AA;
- Cackett, EM;
- Carini, MT;
- Croxall, KV;
- Crenshaw, DM;
- Bontà, E Dalla;
- De Lorenzo-Cáceres, A;
- Dietrich, M;
- Efimova, NV;
- Ely, J;
- Evans, PA;
- Filippenko, AV;
- Flatland, K;
- Gehrels, N;
- Geier, S;
- Gelbord, JM;
- Gonzalez, L;
- Gorjian, V;
- Grier, CJ;
- Grupe, D;
- Hall, PB;
- Hicks, S;
- Horenstein, D;
- Hutchison, T;
- Im, M;
- Jensen, JJ;
- Joner, MD;
- Jones, J;
- Kaastra, J;
- Kaspi, S;
- Kelly, BC;
- Kennea, JA;
- Kim, SC;
- Kim, M;
- Klimanov, SA;
- Korista, KT;
- Kriss, GA;
- Lee, JC;
- Leonard, DC;
- Lira, P;
- MacInnis, F;
- Manne-Nicholas, ER;
- Mathur, S;
- McHardy, IM;
- Montouri, C;
- Musso, R;
- Nazarov, SV;
- Norris, RP;
- Nousek, JA;
- Okhmat, DN;
- Pancoast, A;
- Parks, JR;
- Pei, L;
- Pogge, RW;
- Pott, J-U;
- Rafter, SE;
- Rix, H-W;
- Saylor, DA;
- Schimoia, JS;
- Schnülle, K;
- Sergeev, SG;
- Siegel, MH;
- Spencer, M;
- Sung, H-I;
- Teems, KG;
- Turner, CS;
- Uttley, P;
- Vestergaard, M;
- Villforth, C;
- Weiss, Y;
- Woo, J-H;
- Yan, H;
- Young, and S;
- Zheng, W;
- Zu, Y
We conduct a multiwavelength continuum variability study of the Seyfert 1 galaxy NGC 5548 to investigate the temperature structure of its accretion disk. The 19 overlapping continuum light curves (1158 A oto 9157 A o) combine simultaneous Hubble Space Telescope, Swift, and ground-based observations over a 180 day period from 2014 January to July. Light-curve variability is interpreted as the reverberation response of the accretion disk to irradiation by a central time-varying point source. Our model yields the disk inclination i = 36° ±10° temperature T1 = 44 ±6 ) × 10 3 K at 1 light day from the black hole, and a temperatureradius slope (T ∞r-a) of a = 0.99 ±0.03. We also infer the driving light curve and find that it correlates poorly with both the hard and soft X-ray light curves, suggesting that the X-rays alone may not drive the ultraviolet and optical variability over the observing period. We also decompose the light curves into bright, faint, and mean accretion-disk spectra. These spectra lie below that expected for a standard blackbody accretion disk accreting at L LEdd = 0.1.