J/A+A/640/A31 R-Gamma correlation of Swift/BAT AGN (Panagiotou+, 2020)
NuSTAR view of Swift/BAT AGN: The R-Gamma correlation.
Panagiotou C., Walter R.
<Astron. Astrophys. 640, A31 (2020)>
=2020A&A...640A..31P 2020A&A...640A..31P (SIMBAD/NED BibCode)
ADC_Keywords: Active gal. nuclei ; X-ray sources
Keywords: galaxies: active - galaxies: nuclei - galaxies: Seyfert -
X-rays: galaxies
Abstract:
The reflection hump is a prominent feature in the hard X-ray spectrum
of active galactic nuclei (AGN). Its exact shape and its correlation
to other quantities provide valuable information about the inner and
outer regions of an AGN.
Our main goal is to study the reflection hump in a large sample of
nearby AGN. We aim to investigate the evolution of reflection with
absorption and its correlation with the spectral index.
We analysed archived NuSTAR observations of the 70-month BAT catalogue
AGN. By performing a detailed spectral analysis, we were able to
constrain the spectral parameters and to investigate the reflection
emission in a large sample of individual sources.
The reflection strength was found to be strongly correlated with the
power-law slope in unabsorbed sources, pointing towards disc
reflection for these sources. Different possible explanations were
tested and the most likely one is that the corona is moving either
towards or away from the disc with a moderately relativistic velocity.
An R-Gamma correlation was not detected for absorbed sources. In
addition, these AGN feature harder spectra, suggesting intrinsic
differences between the two classes or a slab geometry for the X-ray
source.
Description:
Using archived NuSTAR observations we studied the hard X-ray spectrum
of Swift/BAT AGN. We derived the spectral parameters for more than 200
sources, when the pexrav model is used. The best-fit parameters,
observation information and details about the sources are given in the
tables.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table24.dat 193 236 Sources characteristics and best-fit results
(tables 2 and 4)
table3.dat 58 316 Observational details
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See also:
B/swift : Swift Master Catalog (HEASARC, 2004-)
IX/58 : 2SXPS Swift X-ray telescope point source catalogue (Evans+, 2020)
Byte-by-byte Description of file: table24.dat
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Bytes Format Units Label Explanations
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1- 5 A5 --- --- [SWIFT]
7- 19 A13 --- SWIFT Source name in the Swift/BAT 70-month
catalog (1)
20 A1 --- n_SWIFT [+] Note on SWIFT (2)
22- 45 A24 --- OName Counterpart source name
47- 54 F8.4 deg RAdeg Right Ascension (J2000)
57- 64 F8.4 deg DEdeg Declination (J2000)
67- 72 F6.4 --- z Redshift (3)
75 I1 --- BATclass BAT class in the 70-month catalog
78- 81 A4 --- NHclass Class based on N_H classification (6)
86 A1 --- l_NH Limit flag on N_H
87- 91 F5.2 10+22cm-2 NH Column density of the absorbing matter
92- 94 F3.1 10+22cm-2 E_NH ? Upper error on N_H
96- 98 F3.1 10+22cm-2 e_NH ? Lower error on N_H
111 A1 --- f_Gamma Flag f indicating Gamma was kept fixed
during the fit (4)
112-115 F4.2 --- Gamma Best-fit power-law slope
117-120 F4.2 --- E_Gamma ? Upper error on Gamma
122-125 F4.2 --- e_Gamma ? Lower error on Gamma
135 A1 --- l_R Limit flag on R
136-140 F5.3 --- R Best-fit reflection parameter
141-144 F4.2 --- E_R ? Upper error on R
146-149 F4.2 --- e_R ? Lower error on R
153 A1 --- l_EW Limit flag on EW
154-156 I3 eV EW Equivalent width of Fe K-alpha line
158-159 I2 eV E_EW ? Upper error on EW (5)
161-163 I3 eV e_EW ? Lower error on EW (5)
165 A1 --- l_Ec Limit flag on Ec
166-170 I5 keV Ec Best-fit high-energy cutoff
172-175 I4 keV E_Ec ? Upper error on Ec
177-180 I4 keV e_Ec ? Lower error on Ec
183-188 F6.1 --- chi2 chi-square statistic
190-193 I4 --- dof Degrees of freedom of the fit
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Note (1): For some sources, it colud have different observations,
one line per observation.
Note (2): + indicate that this source has been already analysed in
Panagiotou & Walter (2019A&A...626A..40P 2019A&A...626A..40P).
Note (3): The redshift was retrieved from NED (https://ned.ipac.caltech.edu/)
and SIMBAD (http://simbad.u-strasbg.fr/simbad/).
Note (4): The photon index was frozen at a value of 1.73 for several sources,
because leaving it free resulted in Gamma<1.4.
Note (5): The error on equivalent width was estimated with NH and R being fixed
to their best-fit values and thus is only an underestimation of the real
error.
Note (6): We have defined three groups as follows;
UNOB = the unobscured (NH<5x1022cm-2) class
LOB = lightly obscured (5x1022cm-2<NH<1x1023cm-2) class
MOB = the mildly obscured (NH>1x1023cm-2) class
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Byte-by-byte Description of file: table3.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 5 A5 --- --- [SWIFT]
7- 19 A13 --- SWIFT Source name in the Swift/BAT 70-month catalog
25- 35 I11 --- obsId NuSTAR observation ID
40- 48 F9.3 d Date Start date of each observation (MJD)
53- 58 F6.2 ks Exp Exposure time
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Acknowledgements:
Christos Panagiotou, christos.panagiotou(at)unige.ch
References:
Panagiotou & Walter. 2019A&A...626A..40P 2019A&A...626A..40P,
Reflection geometries in absorbed and unabsorbed AGN
(End) Patricia Vannier [CDS] 02-Jul-2020