A 12-day ASCA Observation of the Narrow-Line Seyfert 1 Galaxy Ton S180: Time-Selected Spectroscopy

dc.creatorRomano, P.
dc.creatorTurner, T. J.
dc.creatorMathur, S.
dc.creatorGeorge, I. M.
dc.date2001-08-06
dc.date.accessioned2026-07-07T10:31:07Z
dc.date.available2026-07-07T10:31:07Z
dc.descriptionWe present an analysis of the X-ray variability properties of the NLS1 galaxy Ton S180, based upon a 12-day continuous ASCA observation. We observe flux variations of a factor of 3.5 in the 0.7-1.3 keV band and 3.9 in the 2-10 keV band.Time-resolved spectroscopy (~1d sampling) reveals that the broad `soft hump' component at energies <2 keV shows flux variations on timescales down to 1 day that are well correlated with the photon index and the 2-10 keV band flux. A broad Fe K$α$ emission is detected. There is a evidence for a narrow Fe K$α$ line at ~6.8 keV, indicating an origin in ionized material. We do not detect significant variations of the line flux or EW on ~1 day-1 week timescales. The softness ratio reveals spectral variability on timescales down to ~1000 s, indicating that the power-law continuum and soft hump fluxes are not well correlated on this timescale. It also shows a slow decline across the observation, due to a combination of the different time-variability of the power-law continuum and soft hump flux on timescales of ~1 week. The X-ray emission originates within 12 Schwarzschild radii, and the amplitudes and timescales of the rapid variations we observed are consistent with those expected within disk-corona models. The soft hump variability timescale rules out an origin in large scale components (circumnuclear starburst). The $Γ$-soft hump correlation is consistent with the soft hump being produced by up-scattering of the accretion disk radiation within a flaring disk corona.
dc.description11 pages, 9 figures; accepted for publication in The Astrophysical Journal, LaTeX emulateapj.sty
dc.identifierhttps://arxiv.org/abs/astro-ph/0108096
dc.identifierhttp://arxiv.org/abs/astro-ph/0108096
dc.identifierAstrophys.J.564:162-175,2002
dc.identifierdoi:10.1086/324201
dc.identifier.urihttp://salesiana.dossiersoluciones.com/handle/123456789/178308
dc.subjectAstrophysics
dc.titleA 12-day ASCA Observation of the Narrow-Line Seyfert 1 Galaxy Ton S180: Time-Selected Spectroscopy
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