Twelve years of X-ray and optical variability in the Seyfert galaxy NGC 4051
文献类型：期刊论文
| 作者 | Breedt, E.1; McHardy, I. M.1; Arevalo, P.8,9; Uttley, P.1; Sergeev, S. G.10; Minezaki, T.2; Yoshii, Y.2,3; Sakata, Y.4; Lira, P.5; Chesnok, N. G.6,7 |
| 刊名 | MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY
 |
| 出版日期 | 2010-04-01 |
| 卷号 | 403期号:2页码:605-619 |
| 关键词 | galaxies: active galaxies: individual: NGC 4051 galaxies: Seyfert |
| 英文摘要 | We discuss the origin of the optical variations in the narrow-line Seyfert 1 galaxy NGC 4051 and present the results of a cross-correlation study using X-ray and optical light curves spanning more than 12 years. The emission is highly variable in all wavebands, and the amplitude of the optical variations is found to be smaller than that of the X-rays, even after correcting for the contaminating host galaxy flux falling inside the photometric aperture. The optical power spectrum is best described by an unbroken power-law model with slope alpha = 1.4+0.6(-0.2) and displays lower variability power than the 2-10 keV X-rays on all time-scales probed. We find the light curves to be significantly correlated at an optical delay of 1.2+1.0(-0.3) d behind the X-rays. This time-scale is consistent with the light traveltime to the optical emitting region of the accretion disc, suggesting that the optical variations are driven by X-ray reprocessing. We show, however, that a model whereby the optical variations arise from reprocessing by a flat accretion disc cannot account for all the optical variability. There is also a second significant peak in the cross-correlation function, at an optical delay of 39+2.7(-8.4) d. The lag is consistent with the dust sublimation radius in this source, suggesting that there is a measurable amount of optical flux coming from the dust torus. We discuss the origin of the additional optical flux in terms of reprocessing of X-rays and reflection of optical light by the dust. |
| WOS标题词 | Science & Technology ; Physical Sciences |
| 类目[WOS] | Astronomy & Astrophysics |
| 研究领域[WOS] | Astronomy & Astrophysics |
| 关键词[WOS] | ACTIVE GALACTIC NUCLEI ; BROAD-LINE REGION ; AGN DUSTY TORI ; XMM-NEWTON ; REVERBERATION MEASUREMENTS ; LUMINOSITY RELATIONSHIP ; CONTINUUM EMISSION ; ACCRETION DISKS ; INNER RADIUS ; BLACK-HOLES |
| 收录类别 | SCI |
| 语种 | 英语 |
| WOS记录号 | WOS:000275760900005 |
| 源URL | [http://119.78.226.72/handle/331011/26358]  |
| 专题 | 上海天文台_星系宇宙学重点实验室 |
| 作者单位 | 1.Univ Southampton, Sch Phys & Astron, Southampton SO17 1BJ, Hants, England 2.Univ Tokyo, Sch Sci, Astron Inst, Tokyo 1810015, Japan 3.Univ Tokyo, Sch Sci, Res Ctr Early Universe, Bunkyo Ku, Tokyo 1130033, Japan 4.Univ Tokyo, Sch Sci, Dept Astron, Bunkyo Ku, Tokyo 1130033, Japan 5.Univ Chile, Dept Astron, Santiago, Chile 6.Taras Shevchenko Natl Univ Kiev, UA-03680 Kiev, Ukraine 7.Ukrainian Natl Acad Sci, Main Astron Observ, UA-03680 Kiev, Ukraine 8.Shanghai Astron Observ, Shanghai 200030, Peoples R China 9.Univ Andres Bello, Dept Ciencias Fis, Santiago, Chile 10.Crimean Astrophys Observ, UA-98409 P O Nauchny, Crimea, Ukraine |
| 推荐引用方式 GB/T 7714 | Breedt, E.,McHardy, I. M.,Arevalo, P.,et al. Twelve years of X-ray and optical variability in the Seyfert galaxy NGC 4051[J]. MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,2010,403(2):605-619. |
| APA | Breedt, E..,McHardy, I. M..,Arevalo, P..,Uttley, P..,Sergeev, S. G..,...&Chesnok, N. G..(2010).Twelve years of X-ray and optical variability in the Seyfert galaxy NGC 4051.MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY,403(2),605-619. |
| MLA | Breedt, E.,et al."Twelve years of X-ray and optical variability in the Seyfert galaxy NGC 4051".MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY 403.2(2010):605-619. |
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来源：上海天文台
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