A 10-day ASCA Observation of the Narrow-line Seyfert~1 galaxy IRAS 13224-3809

Abstract

(Abridged) We present an analysis of a 10-day continuous ASCA observation of the narrow-line Seyfert 1 galaxy IRAS 13224-3809. The soft (0.7-1.3 keV) and hard (1.3-10 keV) X-ray band light curves binned to 5000s reveal trough-to-peak variations by a factor >25 and 20, respectively. The light curves in the soft and hard bands are strongly correlated without any significant delay. However, this correlation is not entirely due to changes in the power-law flux alone but also due to changes in the soft X-ray hump emission above the power law. The presence of a soft X-ray hump below 2 keV, previously detected in ROSAT and ASCA data, is confirmed. Time resolved spectroscopy using daily sampling reveals changes in the power-law slope, with Gamma in the range 1.74-2.47, however, day-to-day variations in Gamma are not significant. The Soft hump emission is found to dominate the observed variability on a timescale of a week, but on shorter timescales (20000s) the power-law component appears to dominate the observed variability. Flux resolved spectroscopy reveals that at high flux levels the power law becomes steeper and the soft hump more pronounced. The steepening of the photon index with the fluxes in the soft and hard bands can be understood in the framework of disk/corona models in which accretion disk is heated by viscous dissipation as well as by reprocessing of hard X-rays following an X-ray flare resulting from coronal dissipation through magnetic reconnection events.

29 pages, 16 figures, To apear in A&A

References in corpus (11)

• The central kiloparsec of starbursts and AGN: The La Palma connection
• High-Resolution X-ray and Ultraviolet Spectroscopy of the Complex Intrinsic Absorption in NGC 4051 with Chandra and HST
• The Fragmentation of Pre-enriched Primordial Objects
• Multiwavelength Monitoring of the Narrow-Line Seyfert 1 Galaxy Akn 564. I. ASCA Observations and the Variability of the X-ray Spectral Components
• The broad-band spectrum of 3C 120 observed by BeppoSAX
• Temporal characteristics of the X-ray emission of NGC 7469
• Chandra Grating Spectroscopy of the Seyfert Galaxy Ton S180
• A 12-day ASCA Observation of the Narrow-Line Seyfert 1 Galaxy Ton S180: Time-Selected Spectroscopy
• X-ray variability of AGN and correlations with spectral properties
• Accretion and emission processes in AGN
• Optical and X-ray characteristics of a newly discovered narrow-line QSO : RX J1334.2+3759

Cited by in corpus (28)

• On characterising the variability properties of X-ray light curves from active galaxies
• Non-linear X-ray variability in X-ray binaries and active galaxies
• HST STIS Ultraviolet Spectral Evidence for Outflow in Extreme Narrow-line Seyfert 1 Galaxies: I. Data and Analysis
• Investigating the nature of narrow-line Seyfert 1 galaxies with high-energy spectral complexity
• Long XMM observation of the Narrow-Line Seyfert 1 galaxy IRAS13224-3809: rapid variability, high spin and a soft lag
• Extreme Slim Accretion Disks and Narrow Line Seyfert 1 Galaxies: the Nature of the soft X-ray Hump
• Relativistic disc reflection in the extreme NLS1 IRAS13224-3809
• An investigation of the origin of soft X-ray excess emission from Narrow-line Seyfert 1 galaxies Akn564 and Mrk1044
• The remarkable X-ray variability of IRAS 13224-3809 I: The variability process
• The X-Ray Variability of a Large, Serendipitous Sample of Spectroscopic Quasars
• The X-ray variability of the Narrow-Line Seyfert 1 galaxy IRAS 13224-3809 from an XMM-Newton observation
• Slim Disks with Transition Regions and Applications to Microquasars and Narrow Line Seyfert 1 Galaxies
• A combined timing/spectral study of IRAS 13224-3809 using XMM-Newton data
• XMM-Newton observations of Broad FeKalpha emission from a Seyfert 1.9 galaxy MCG-5-23-16
• M74 X-1 (CXOU J013651.1+154547): An Extremely Variable Ultraluminous X-Ray Source
• Is there a UV/X-ray connection in IRAS 13224-3809?
• Chandra LETGS and XMM-Newton observations of NGC 4593
• Relationship between X-ray spectral index and X-ray Eddington ratio for Mrk 335 and Ark 564
• The X-ray continuum time-lags and intrinsic coherence in AGN
• Swift, INTEGRAL, RXTE, and Spitzer reveal IGR J16283-4838
• Chandra Observations of the NLS1 RX J2217.9-5941
• XMM observations of the narrow-line QSO PHL 1092: Detection of a high and variable soft component
• The Correlation between X-ray spectral slope and FeKalpha line energy in radio-quiet active galactic nuclei
• Applying wavelet analysis to the X-ray light curves of active galactic nuclei and quasi-periodic eruptions
• Revealing Thermal Comptonization of accretion-disk photons in IC4329A with AstroSat
• The broad-band spectrum of the Narrow-line Seyfert 1 NGC 4748: from UV to hard X-ray
• Swift Observations of the highly X-ray variable Narrow Line Seyfert 1 galaxy RX J0148.3-2758
• Can the relativistic light bending model explain X-ray spectral variations of Seyfert galaxies?