Relationship between X-ray spectral index and X-ray Eddington ratio for Mrk 335 and Ark 564

Abstract

We present a comprehensive flux resolved spectral analysis of the bright Narrow line Seyfert I AGNs, Mrk~335 and Ark~564 using observations by XMM-Newton satellite. The mean and the flux resolved spectra are fitted by an empirical model consisting of two Comptonization components, one for the low energy soft excess and the other for the high energy power-law. A broad Iron line and a couple of low energies edges are required to explain the spectra. For Mrk~335, the 0.3 - 10 keV luminosity relative to the Eddington value, L{${}_X$}/L${}_{Edd}$, varied from 0.002 to 0.06. The index variation can be empirically described as $\Gamma$ = 0.6 log${}_{10}$ L{${}_X$}/L${}_{Edd}$ + 3.0 for $0.005<L{}_X/L_{Edd}<0.04$. At $L_X/L_{Edd}\sim 0.04$ the spectral index changes and then continues to follow $\Gamma$ = 0.6 log${}_{10}$ L${}_X$/L${}_{Edd}$ + 2.7, i.e. on a parallel track. We confirm that the result is independent of the specific spectral model used by fitting the data in the 3 - 10 keV band by only a power-law and an Iron line. For Ark~564, the index variation can be empirically described as $\Gamma$ = 0.2 log${}_{10}$ L${}_X$/L${}_{Edd}$ + 2.7 with a significantly large scatter as compared to Mrk~335. Our results indicate that for Mrk~335, there may be accretion disk geometry changes which lead to different parallel tracks. These changes could be related to structural changes in the corona or enhanced reflection at high flux levels. There does not seem to be any homogeneous or universal relationship for the X-ray index and luminosity for different AGNs or even for the same AGN.

arXiv commentAccepted for publication in the MNRAS

References in corpus (57)

• The Leiden/Argentine/Bonn (LAB) Survey of Galactic HI: Final data release of the combined LDS and IAR surveys with improved stray-radiation corrections
• Central Masses and Broad-Line Region Sizes of Active Galactic Nuclei. II. A Homogeneous Analysis of a Large Reverberation-Mapping Database
• The Soft X-Ray Properties of a Complete Sample of Optically Selected Quasars II. Final Results
• Black Hole Mass and Eddington Ratio as Drivers for the Observable Properties of Radio-Loud and Radio-Quiet QSOs
• Systematic Effects in Measurement of Black Hole Masses by Emission-Line Reverberation of Active Galactic Nuclei: Eddington Ratio and Inclination
• A Comprehensive Spectral and Variability Study of Narrow-Line Seyfert 1 Galaxies Observed by ASCA: II. Spectral Analysis and Correlations
• A Simple Comptonization Model
• A spectrophotometric atlas of Narrow-Line Seyfert 1 galaxies
• XMM-Newton EPIC observations of 21 low-redshift PG quasars
• A comparison of the hard ASCA spectral slopes of broad and narrow-line Seyfert 1 galaxies
• The Hard X-ray Spectral Slope as an Accretion-Rate Indicator in Radio-Quiet Active Galactic Nuclei
• A statistical relation between the X-ray spectral index and Eddington ratio of active galactic nuclei in deep surveys
• A Complete Sample of Soft X-ray Selected AGN: II. Statistical Analysis
• Dwarf Seyfert 1 Nuclei and the Low-Mass End of the M-sigma Relation
• The long term X-ray spectral variability of AGN
• Hot Disk Corona and Magnetic Turbulence in Radio-Quiet Active Galactic Nuclei: Observational Constraints
• A combined Optical and X-ray Spectra Study for Type 1 AGN. III. Broadband SED Properties
• Simultaneous EUVE/ASCA/RXTE Observations of NGC 5548
• XMM-Newton spectroscopy of high-redshift QSOs
• The anti-correlation between the hard X-ray photon index and the Eddington ratio in LLAGNs
• The SDSS/XMM-Newton Quasar Survey: Correlation between X-ray spectral slope and Eddington ratio
• Observations of Seyferts by OSSE and parameters of their X-ray/gamma-ray sources
• The Origin of the X-ray and Ultraviolet Emission in NGC 7469
• Narrow-line Seyfert 1 Galaxies and the M_BH - sigma Relation
• Active Galactic Nuclei Emission-Line Properties Versus Eddington Ratio
• The variable X-ray spectrum of Markarian 766 - I. Principal components analysis
• An accretion disc-corona model for X-ray spectra of active galactic nuclei
• Evidence for Rapid Iron K_alpha Line Flux Variability in MCG--6-30-15
• Narrow-line Seyfert 1 Galaxies from the Sloan Digital Sky Survey Early Data Release
• Exploring NLS1 through the physical properties of their hosts
• Probing the Balance of AGN and Star-Forming Activity in the Local Universe with ChaMP
• Study of LINER sources with broad H(alpha) emission. X-ray properties and comparision to luminous AGN and X-ray binaries
• XMM-Newton observations of the Narrow-Line Seyfert 1 galaxy Mrk 335 in an historical low X-ray flux state
• Multiwavelength Monitoring of the Narrow-Line Seyfert 1 Galaxy Akn 564. I. ASCA Observations and the Variability of the X-ray Spectral Components
• A Reverberation Lag for the High-Ionization Component of the Broad Line Region in the Narrow-Line Seyfert 1 Mrk 335
• An investigation of the origin of soft X-ray excess emission from Narrow-line Seyfert 1 galaxies Akn564 and Mrk1044
• A blurred reflection interpretation for the intermediate flux state in Mrk 335
• Multiwavelength Monitoring of the Narrow-Line Seyfert 1 Galaxy Akn 564. III. Optical Observations and the Optical--UV--X-ray Connection
• A remarkable long-term light curve, and deep, low-state spectroscopy: Swift & XMM-Newton monitoring of the NLS1 galaxy Mkn 335
• Two Different Accretion Classes in Seyfert 1 Galaxies and QSOs
• The broad-band spectrum of 3C 120 observed by BeppoSAX
• Temporal characteristics of the X-ray emission of NGC 7469
• Confirmation of a correlation between the X-ray luminosity and spectral slope of AGNs in the Chandra Deep Fields
• Evidence for relativistic features in the X-ray spectrum of Mrk 335
• Chandra Observations of X-ray Weak Narrow-Line Seyfert 1 Galaxies
• The X-ray variability of the Narrow-Line Seyfert 1 galaxy IRAS 13224-3809 from an XMM-Newton observation
• The Spectral Energy Distribution and Emission-Line properties of the NLS1 Galaxy Arakelian 564
• Suzaku observations of Markarian 335: evidence for a distributed reflector
• XMM-Newton observation of the NLS1 Galaxy Ark 564: I. Spectral analysis of the time-average spectrum
• A 10-day ASCA Observation of the Narrow-line Seyfert~1 galaxy IRAS 13224-3809
• Direct Measurement of the X-ray Time-Delay Transfer Function in Active Galactic Nuclei
• On the relativistic iron line and soft excess in the Seyfert 1 galaxy Markarian 335
• Arakelian 564: An XMM-Newton view
• An AGN Sample with High X-ray-to-optical Flux Ratio from RASS II.Optical Emission Line Properties of Seyfert 1 Type AGN
• Hard X-ray photon index as an indicator of bolometric correction in active galactic nuclei
• The Structure and Spectral Features of a Thin Disk and Evaporation-Fed Corona in High-Luminosity AGNs
• Thermal X-ray iron line emission from the advection dominated accretion flow in the galactic binary GX 339-4

Cited by in corpus (13)

• Long-Term X-ray Variability of Typical Active Galactic Nuclei in the Distant Universe
• Revealing the accretion disc corona in Mrk 335 with multi-epoch X-ray spectroscopy
• Tracking the year-to-year variation in the spectral energy distribution of the Narrow-line Seyfert 1 Galaxy Mrk335
• NuSTAR observation of Ark 564 reveals the variation of coronal temperature with flux
• On Spin Dependence of the Fundamental Plane of Black Hole Activity
• Distinct High Energy Cutoff Variation Patterns in Two Seyfert Galaxies
• Extended Corona Models of X-ray Reverberation in the AGN 1H~0707-495 and IRAS 13224-3809
• More than softer-when-brighter: the X-Ray powerlaw spectral variability in NGC 4051
• X-ray timing and spectral analysis of reverberating active galactic nuclei
• Changing Accretion Geometry of Seyfert 1 Mrk 335 with {\it NuSTAR}: A Comparative Study
• AstroSat view of the NLS1 galaxy Mrk 335
• UV and X-Ray Variability of the Narrow-Line Seyfert 1 Galaxy Ark 564
• Modelling the energy dependent X-ray variability of Mrk 335