Author | dc.contributor.author | McHardy, I. M. | |
Author | dc.contributor.author | Cameron, D. T. | es_CL |
Author | dc.contributor.author | Dwelly, T. | es_CL |
Author | dc.contributor.author | Connolly, S. | es_CL |
Author | dc.contributor.author | Lira Teillery, Paulina | es_CL |
Author | dc.contributor.author | Emmanoulopoulos, D. | es_CL |
Author | dc.contributor.author | Gelbord, J. | es_CL |
Author | dc.contributor.author | Breedt, E. | |
Author | dc.contributor.author | Arevalo, P. | |
Author | dc.contributor.author | Uttley, P. | |
Admission date | dc.date.accessioned | 2014-09-24T20:24:30Z | |
Available date | dc.date.available | 2014-09-24T20:24:30Z | |
Publication date | dc.date.issued | 2014 | |
Cita de ítem | dc.identifier.citation | MNRAS 444, 1469–1474 (2014) | en_US |
Identifier | dc.identifier.other | doi:10.1093/mnras/stu1636 | |
Identifier | dc.identifier.uri | https://repositorio.uchile.cl/handle/2250/126478 | |
General note | dc.description | Artículo de Publicación ISI | en_US |
Abstract | dc.description.abstract | Lags measured from correlated X-ray/UV/optical monitoring of AGN allow us to determine
whether UV/optical variability is driven by reprocessing of X-rays or X-ray variability is
driven by UV/optical seed photon variations. We present the results of the largest study to
date of the relationship between the X-ray, UV and optical variability in an AGN with 554
observations, over a 750 d period, of the Seyfert 1 galaxy NGC 5548 with Swift. There is a good
overall correlation between the X-ray and UV/optical bands, particularly on short time-scales
(tens of days). The UV/optical bands lag the X-ray band with lags which are proportional
to wavelength raised to the power 1.23 ± 0.31. This power is very close to the power (4/3)
expected if short time-scale UV/optical variability is driven by reprocessing of X-rays by
a surrounding accretion disc. The observed lags, however, are longer than expected from a
standard Shakura–Sunyaev accretion disc with X-ray heating, given the currently accepted
black hole mass and accretion rate values, but can be explained with a slightly larger mass
and accretion rate, and a generally hotter disc. Some long-term UV/optical variations are
not paralleled exactly in the X-rays, suggesting an additional component to the UV/optical
variability arising perhaps from accretion rate perturbations propagating inwards through the
disc. | en_US |
Lenguage | dc.language.iso | en_US | en_US |
Publisher | dc.publisher | Royal Astronomical Society | en_US |
Keywords | dc.subject | accretion, accretion discs | en_US |
Título | dc.title | Swift monitoring of NGC 5548: X-ray reprocessing and short-term UV/optical variability | en_US |
Document type | dc.type | Artículo de revista | |