J/MNRAS/448/1541 Spectral parameters for Mrk 335 and Ark 564 (Sarma+, 2015)
Relationship between X-ray spectral index and X-ray Eddington ratio for Mrk 335
and Ark 564.
Sarma R., Tripathi S., Misra R., Dewangan G., Pathak A., Sarma J.K.
<Mon. Not. R. Astron. Soc., 448, 1541-1550 (2015)>
=2015MNRAS.448.1541S 2015MNRAS.448.1541S (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; Galaxies, Seyfert ; X-ray sources ; Models
Keywords: galaxies: Seyfert - X-rays: galaxies
Abstract:
We present a comprehensive flux-resolved spectral analysis of the bright
narrow-line Seyfert 1 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-energy edges are required
to explain the spectra. For Mrk 335, the 0.3-10 keV luminosity relative to
the Eddington value, LX/LEdd, varied from 0.002 to 0.06. The index
variation can be empirically described as Γ=0.6log10LX/LEdd+3.0
for 0.005<LX/LEdd<0.04. At LX/LEdd∼0.04 the spectral index changes
and then continues to follow Γ=0.6log10LX/LEdd+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 Γ=0.2log10LX/LEdd+2.7 with
a significantly large scatter as compared to Mrk 335. Our results indicate
that for Mrk 335, there may be accretion disc 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.
Description:
For the analysis, we use all the available archival data of Mrk 335 and
Ark 564 from the XMM-Newton observatory (Jansen et al. 2001A&A...365L...1J 2001A&A...365L...1J).
The XMM-Newton data have been processed in the standard way using the SAS
version 12.0. For all cases, we have considered data from the EPIC-pn
camera (Struder et al. 2001A&A...365L..18S 2001A&A...365L..18S) only.
Objects:
-------------------------------------------------------
RA (ICRS) DE Designation(s)
-------------------------------------------------------
00 06 19.54 +20 12 10.6 Mrk 335 = IRAS 00037+1955
22 42 39.34 +29 43 31.3 Ark 564 = UGC 12163
-------------------------------------------------------
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table4.dat 143 50 Spectral parameters for each flux state derived
from different XMM-Newton observations in
the (0.3-10.0)keV range
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See also:
J/A+A/437/87 : Mrk 335 photometry in 1995-2004 (Doroshenko+, 2005)
J/ApJ/713/L11 : X-ray properties of Seyfert 1 galaxies (Zhou+, 2010)
J/A+A/551/A95 : Reduced co-added LETGS spectrum of Ark 564 (Ramirez, 2013)
J/ApJ/782/45 : SEAMBHs. I. Mrk 142, Mrk 335, and IRAS F12397+3333 (Du+, 2014)
Byte-by-byte Description of file: table4.dat
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Bytes Format Units Label Explanations
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1- 7 A7 --- Name Galaxy name (Mrk 335 or Akn 564)
9- 18 I10 --- ObsID [6810101/670130901] Observation identifier
20 I1 --- Fstate [1/4] Flux state
22- 29 E8.4 --- tau1 [2e-07/1.297] τ with zedge1 model
31- 37 F7.3 --- E_tau1 [0.015/908.7] Upper limit uncertainty in tau1
39- 43 F5.3 --- e_tau1 [0.002/0.542] Lower limit uncertainty in tau1
45- 49 F5.3 --- tau2 [0.019/0.435] τ with zedge2 model
51- 55 F5.3 --- E_tau2 [0.014/0.145] Upper limit uncertainty in tau2
57- 61 F5.3 --- e_tau2 [0.014/0.148] Lower limit uncertainty in tau2
63- 68 F6.3 --- tau3 [-0.006/0.491]? τ with zedge3 model
70- 74 F5.3 --- E_tau3 [0.014/0.092]? Upper limit uncertainty in tau3
76- 80 F5.3 --- e_tau3 [0.009/0.089]? Lower limit uncertainty in tau3
82- 86 F5.3 --- Gamma1 [1.622/2.537] X-ray photon index Γ with
the "Simpl" model (1)
88- 92 F5.3 --- E_Gamma1 [0.014/0.157] Upper limit uncertainty in Gamma1
94- 98 F5.3 --- e_Gamma1 [0.014/0.151] Lower limit uncertainty in Gamma1
100-104 F5.3 --- Scat [0.065/0.246] Scatter fraction
106-110 F5.3 --- E_Scat [0.004/0.039] Upper limit uncertainty in Scat
112-116 F5.3 --- e_Scat [0.004/0.03] Lower limit uncertainty in Scat
118-122 F5.3 --- Gamma2 [1.86/3.455] X-ray photon index Γ with
the "nthComp" model (1)
124-128 F5.3 --- E_Gamma2 [0.029/0.324] Upper limit uncertainty in Gamma2
130-134 F5.3 --- e_Gamma2 [0.028/0.306] Lower limit uncertainty in Gamma2
136-139 F4.2 --- chi2 [0.8/1.42] Reduced χ2
141-143 I3 --- dof [82/169] Degrees of freedom
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Note (1): We fit the EPIC-pn spectral data in the 0.3-10.0 keV range, by a
simple phenomenological model consisting of two thermal Comptonization models.
In particular, the soft excess is described by the XSPEC model "nthComp" and
for the hard X-ray emission, we have used XSPEC convolution model "Simpl"
(Steiner et al. 2009PASP..121.1279S 2009PASP..121.1279S).
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History:
From electronic version of the journal
(End) Tiphaine Pouvreau [CDS] 27-Jan-2020