1. Space Telescope and Optical Reverberation Mapping Project. IX. Velocity–Delay Maps for Broad Emission Lines in NGC 5548
- Author
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Horne, Keith, De Rosa, G, Peterson, BM, Barth, AJ, Ely, J, Fausnaugh, MM, Kriss, GA, Pei, L, Bentz, MC, Cackett, EM, Edelson, R, Eracleous, M, Goad, MR, Grier, CJ, Kaastra, J, Kochanek, CS, Krongold, Y, Mathur, S, Netzer, H, Proga, D, Tejos, N, Vestergaard, M, Villforth, C, Adams, SM, Anderson, MD, Arévalo, P, Beatty, TG, Bennert, VN, Bigley, A, Bisogni, S, Borman, GA, Boroson, TA, Bottorff, MC, Brandt, WN, Breeveld, AA, Brotherton, M, Brown, JE, Brown, JS, Canalizo, G, Carini, MT, Clubb, KI, Comerford, JM, Corsini, EM, Crenshaw, DM, Croft, S, Croxall, KV, Bontà, E Dalla, Deason, AJ, Dehghanian, M, De Lorenzo-Cáceres, A, Denney, KD, Dietrich, M, Done, C, Efimova, NV, Evans, PA, Ferland, GJ, Filippenko, AV, Flatland, K, Fox, OD, Gardner, E, Gates, EL, Gehrels, N, Geier, S, Gelbord, JM, Gonzalez, L, Gorjian, V, Greene, JE, Grupe, D, Gupta, A, Hall, PB, Henderson, CB, Hicks, S, Holmbeck, E, Holoien, TW-S, Hutchison, T, Im, M, Jensen, JJ, Johnson, CA, Joner, MD, Jones, J, Kaspi, S, Kelly, PL, Kennea, JA, Kim, M, Kim, S, Kim, SC, King, A, Klimanov, SA, Korista, KT, Lau, MW, Lee, JC, Leonard, DC, Li, Miao, Lira, P, Lochhaas, C, Ma, Zhiyuan, MacInnis, F, Malkan, MA, Manne-Nicholas, ER, and Mauerhan, JC
- Subjects
astro-ph.GA ,Astronomical and Space Sciences ,Atomic ,Molecular ,Nuclear ,Particle and Plasma Physics ,Physical Chemistry (incl. Structural) ,Astronomy & Astrophysics - Abstract
In this contribution, we achieve the primary goal of the active galactic nucleus (AGN) STORM campaign by recovering velocity-delay maps for the prominent broad emission lines (Lyα, C iv, He ii, and Hβ) in the spectrum of NGC 5548. These are the most detailed velocity-delay maps ever obtained for an AGN, providing unprecedented information on the geometry, ionization structure, and kinematics of the broad-line region. Virial envelopes enclosing the emission-line responses show that the reverberating gas is bound to the black hole. A stratified ionization structure is evident. The He ii response inside 5-10 lt-day has a broad single-peaked velocity profile. The Lyα, C iv, and Hβ responses extend from inside 2 to outside 20 lt-day, with double peaks at ±2500 km s-1 in the 10-20 lt-day delay range. An incomplete ellipse in the velocity-delay plane is evident in Hβ. We interpret the maps in terms of a Keplerian disk with a well-defined outer rim at R = 20 lt-day. The far-side response is weaker than that from the near side. The line-center delay days gives the inclination i ≈ 45°. The inferred black hole mass is M BH ≈ 7 × 107 M o˙. In addition to reverberations, the fit residuals confirm that emission-line fluxes are depressed during the "BLR Holiday"identified in previous work. Moreover, a helical "Barber-Pole"pattern, with stripes moving from red to blue across the C iv and Lyα line profiles, suggests azimuthal structure rotating with a 2 yr period that may represent precession or orbital motion of inner-disk structures casting shadows on the emission-line region farther out.
- Published
- 2021