J/A+A/588/A70 Hard X-ray view of the soft excess in AGN (Boissay+, 2016)
A hard X-ray view of the soft excess in AGN.
Boissay R., Ricci C., Paltani S.
<Astron. Astrophys., 588, A70-70 (2016)>
=2016A&A...588A..70B 2016A&A...588A..70B (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; X-ray sources
Keywords: accretion, accretion disks - galaxies: active - galaxies: nuclei -
galaxies: Seyfert - X-rays: galaxies
Abstract:
An excess of X-ray emission below 1keV, called soft excess, is
detected in a large fraction of Seyfert 1-1.5s. The origin of this
feature remains debated, as several models have been suggested to
explain it, including warm Comptonization and blurred ionized
reflection. In order to constrain the origin of this component, we
exploit the different behaviors of these models above 10keV. Ionized
reflection covers a broad energy range, from the soft X-rays to the
hard X-rays, while Comptonization drops very quickly in the soft
X-rays. We present here the results of a study done on 102 Seyfert 1s
(Sy 1.0, 1.2, 1.5 and NLSy1) from the Swift BAT 70-Month Hard X-ray
Survey catalog. The joint spectral analysis of Swift/BAT and
XMM-Newton data allows a hard X-ray view of the soft excess that is
present in about 80% of the objects of our sample. We discuss how the
soft-excess strength is linked to the reflection at high energy, to
the photon index of the primary continuum and to the Eddington ratio.
In particular, we find a positive dependence of the soft excess
intensity on the Eddington ratio. We compare our results to
simulations of blurred ionized-reflection models and show that they
are in contradiction. By stacking both XMM-Newton and Swift/BAT
spectra per soft-excess strength, we see that the shape of reflection
at hard X-rays stays constant when the soft excess varies, showing an
absence of link between reflection and soft excess. We conclude that
the ionized-reflection model as the origin of the soft excess is
disadvantaged in favor of the warm Comptonization model in our sample
of Seyfert 1s.
Description:
We use a sample of sources from the Swift (Gehrels et al.,
2004ApJ...611.1005G 2004ApJ...611.1005G) BAT 70-Month Hard X-ray Survey catalog
(Baumgartner et al., 2013, Cat. J/ApJS/207/19), which contains 1210
sources including 292 Seyfert 1s. By cross-correlating the Swift/BAT
catalog with the Veron catalog (Veron-Cetty & Veron, 2010, Cat.
VII/258), we selected only narrow-line Seyfert 1s (NLSy1s) and Seyfert
1s-1.5s (Sy1s-1.5s). Our sample is in this way composed of 102
sources, divided in 37 Sy1.0s, 18 Sy1.2s, 35 Sy1.5s, and 12 NLSy1s. We
selected sources that have been observed with the XMM-Newton satellite
(Jansen et al., 2001A&A...365L...1J 2001A&A...365L...1J) as pointed observations with a
minimum exposure time of 5 ks (see Table A.1). We selected sources
with a flux higher than 10-11ergs/s/cm2 in the 14-195keV band. BAT
spectra (Barthelmy et al., 2005SSRv..120..143B 2005SSRv..120..143B) have been obtained
from the Swift/BAT website1.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablea1.dat 73 102 List of the sources used for this study
tablea2.dat 146 102 EPIC-PN and MOS XMM-Newton and Swift/BAT data
analysis
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See also:
J/ApJS/207/19 : Hard X-ray survey from Swift-BAT 2004-2010 (Baumgartner+, 2013)
Byte-by-byte Description of file: tablea1.dat
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Bytes Format Units Label Explanations
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1- 23 A23 --- Source Source name
25 A1 --- n_Source [a] Note on Source (1)
27- 32 A6 --- Type Seyfert type
34- 38 F5.3 --- z Redshift
40- 44 F5.2 10+20cm-2 NHG Galactic hydrogen column density (2)
46- 55 A10 "date" Obs.date Observation date (soft X-ray observations)
57- 66 I10 --- Obs.ID Observation ID (soft X-ray observations)
68- 73 F6.2 ks ExpTime Net exposure time (soft X-ray observations)
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Note (1): a: Source presented pile-up and the extraction region used is an
annulus of inner radius 15 arcsec.
Note (2): from Dickey & Lockman, 1990ARA&A..28..215D 1990ARA&A..28..215D.
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Byte-by-byte Description of file: tablea2.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 23 A23 --- Source Source name
26- 29 F4.2 --- GAMMA ?=- GAMMA index
31- 35 F5.3 --- E_GAMMA ? Error on GAMMA (upper value)
37- 41 F5.3 --- e_GAMMA ? Error on GAMMA (lower value)
43- 46 F4.2 10-14W/m2 FCont ?=- Continuum (2-10keV) flux
48- 53 F6.4 10-14W/m2 E_FCont ? Error on FCont (upper value)
55- 60 F6.4 10-14W/m2 e_FCont ? Error on FCont (lower value)
63- 66 F4.2 10-14W/m2 FSE ?=- Soft (0.5-2keV) excess flux
68- 73 F6.4 10-14W/m2 E_FSE ? Error on FSE (upper value)
75- 80 F6.4 10-14W/m2 e_FSE ? Error on FSE (lower value)
82- 99 A18 --- Model Model used (3)
101 A1 --- r_Model [a-l] Reference for Model (4)
103-106 F4.2 --- q ?=- Strength of the soft excess q
108-112 F5.3 --- E_q ? Error on q (upper value)
114-118 F5.3 --- e_q ? Error on q (lower value)
120-124 E5.2 --- R ?=- Reflection factor R
126-130 E5.2 --- E_R ? Error on R (upper value)
131-135 E5.3 --- e_R ? Error on R (lower value)
137-141 I5 --- chi2 ?=- χ2 value
142 A1 --- --- [/]
143-146 I4 --- dof ?=- Degree of freedom
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Note (3): Models as follows:
brem = Bremsstrahlung models
WA = warm absorption
Abs/Cold abs = cold absorption
Note (4): References as follows:
a = Miniutti et al. (2014MNRAS.437.1776M 2014MNRAS.437.1776M)
b = Turner et al. (1996ApJ...463..134T 1996ApJ...463..134T)
c = Steenbrugge et al. (2005A&A...432..453S 2005A&A...432..453S)
d = Miyakawa et al. (2012PASJ...64..140M 2012PASJ...64..140M)
e = Reynolds et al. (1995MNRAS.276.1311R 1995MNRAS.276.1311R)
f = Mingo et al. (2011ApJ...731...21M 2011ApJ...731...21M)
g = Noda et al. (2014ApJ...794....2N 2014ApJ...794....2N)
h = Huerta et al. (2014ApJ...793...61H 2014ApJ...793...61H)
i = Brenneman et al. (2011ApJ...736..103B 2011ApJ...736..103B)
j = Pounds & King (2013MNRAS.433.1369P 2013MNRAS.433.1369P)
k = Wang et al. (2011ApJ...742...23W 2011ApJ...742...23W)
l = Ricci et al. (2010A&A...518A..47R 2010A&A...518A..47R)
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 13-Jun-2016