Details

Autor(en) / Beteiligte

• Edelson, R.
• Gelbord, J.
• Cackett, E.
• Connolly, S.
• Done, C.
• Fausnaugh, M.
• Gardner, E.
• Gehrels, N.
• Goad, M.
• Horne, K.
• McHardy, I.
• Peterson, B. M.
• Vaughan, S.
• Vestergaard, M.
• Breeveld, A.
• Barth, A. J.
• Bentz, M.
• Bottorff, M.
• Brandt, W. N.
• Crawford, S. M.
• Bontà, E. Dalla
• Emmanoulopoulos, D.
• Evans, P.
• Jaimes, R. Figuera
• Filippenko, A. V.
• Ferland, G.
• Grupe, D.
• Joner, M.
• Kennea, J.
• Korista, K. T.
• Krimm, H. A.
• Kriss, G.
• Leonard, D. C.
• Mathur, S.
• Netzer, H.
• Nousek, J.
• Page, K.
• Romero-Colmenero, E.
• Siegel, M.
• Starkey, D. A.
• Treu, T.
• Vogler, H. A.
• Winkler, H.
• Zheng, W.

Titel

Swift Monitoring of NGC 4151: Evidence for a Second X-Ray/UV Reprocessing

Ist Teil von

• The Astrophysical journal, 2017-05, Vol.840 (1), p.41

Ort / Verlag

Philadelphia: The American Astronomical Society

Erscheinungsjahr

2017

Link zum Volltext

Quelle

Free E-Journal (出版社公開部分のみ）

Beschreibungen/Notizen

• Swift monitoring of NGC 4151 with an ∼6 hr sampling over a total of 69 days in early 2016 is used to construct light curves covering five bands in the X-rays (0.3-50 keV) and six in the ultraviolet (UV)/optical (1900-5500 Å). The three hardest X-ray bands (>2.5 keV) are all strongly correlated with no measurable interband lag, while the two softer bands show lower variability and weaker correlations. The UV/optical bands are significantly correlated with the X-rays, lagging ∼3-4 days behind the hard X-rays. The variability within the UV/optical bands is also strongly correlated, with the UV appearing to lead the optical by ∼0.5-1 days. This combination of 3 day lags between the X-rays and UV and 1 day lags within the UV/optical appears to rule out the "lamp-post" reprocessing model in which a hot, X-ray emitting corona directly illuminates the accretion disk, which then reprocesses the energy in the UV/optical. Instead, these results appear consistent with the Gardner & Done picture in which two separate reprocessings occur: first, emission from the corona illuminates an extreme-UV-emitting toroidal component that shields the disk from the corona; this then heats the extreme-UV component, which illuminates the disk and drives its variability.