J/ApJS/121/473 A diagnostic diagram for Seyfert 2 Galaxies (Bassani+, 1999)
A Three-dimensional Diagnostic Diagram for Seyfert 2 Galaxies:
Probing X-Ray Absorption and Compton Thickness
Bassani L., Dadina M., Maiolino R., Salvati M., Risaliti G.,
Della Ceca R., Matt G., Zamorani G.
<Astrophys. J. Suppl. Ser. 121, 473 (1999)>
=1999ApJS..121..473B 1999ApJS..121..473B (SIMBAD/NED BibCode)
ADC_Keywords: Galaxies, Seyfert; X-ray sources
Keywords: galaxies: Seyfert - X-rays: galaxies
Abstract:
We present and discuss a three-dimensional diagnostic diagram for
Seyfert 2 galaxies obtained using X-ray and [O III] data on a large
sample of objects (reported in the Appendix). The diagram shows the
Kα iron line equivalent width as a function of both the column
density derived from the photoelectric cutoff and the 2-10 keV flux
normalized to the [O III] optical-line flux (the latter corrected for
extinction and assumed to be a true indicator of the source intrinsic
luminosity). We find that the hard X-ray properties of type 2 objects
depend on a single parameter, the absorbing column density along the
line of sight, in accordance with the unified model. The diagram can
be used to identify Compton-thick sources and to isolate and study
peculiar objects. From this analysis we have obtained a column density
distribution of Seyfert 2 galaxies that is thought to be a good
approximation of the real distribution. A large population of heavily
absorbed objects is discovered, including many Compton-thick
candidates. Our results indicate that the mean log NHcm-2 in type
2 Seyfert galaxies is 23.5 and that as many as 23%-30% of sources
have NH=>1024cm-2.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table1.dat 130 73 Catalog of Seyfert 2 Galaxies
table2.dat 131 73 Seyfert 2 spectral parameters
refs.dat 138 98 References for table1.dat and table2.dat
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Byte-by-byte Description of file: table1.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name Seyfert galaxy name
21- 22 I2 h RAh Right Ascension (J2000)
24- 25 I2 min RAm Right Ascension (J2000)
27- 30 F4.1 s RAs Right Ascension (J2000)
33 A1 --- DE- Sign of the Declination (J2000)
34- 35 I2 deg DEd Declination (J2000)
37- 38 I2 arcmin DEm Declination (J2000)
40- 41 I2 arcsec DEs Declination (J2000)
43- 50 F8.5 --- z Redshift
52- 63 A12 --- Class Seyfert classification: S=Seyfert,
L=Liner, SB=Starburst
64- 70 A7 --- r_z Reference for z and Class in refs.dat
72- 76 F5.2 10+20cm-2 ColD Galactic H I column density
82 A1 --- l_Rat Limit on Rat
83- 87 F5.2 --- Rat ? Ratio of Hα to H[beta
90- 99 A10 --- r_ColD References for ColD and Rat in refs.dat
101 A1 --- l_OIII Limit on OIII
102-107 F6.3 10-11mW/m2 OIII ? Corrected [O III] flux
109-113 F5.3 10-11mW/m2 e_OIII ? uncertainty on the [O III] flux
118 A1 --- n_OIII Remark on OIII (1)
121-130 A10 --- r_OIII References for OIII in refs.dat
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Note (1): For this object, the only [O III] measurement available was taken
with an aperture smaller than 100 pc as projected on the source, and
therefore these data are likely to miss a significant fraction of the
[O III] flux
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 19 A19 --- Name Seyfert Galaxy name
21 A1 --- n_Name [ehg] Name flag (1)
24- 28 F5.2 --- Gamma The photon index
30- 34 F5.2 --- E_Gamma ? upper limit on Gamma
36- 40 F5.2 --- e_Gamma ? lower limit on Gamma
42 A1 --- n_Gamma [fj] note on Gamma: f = Fixed photon
index, j = Parameter is pegged at
the higher limit
45 A1 --- l_ColD Lower limit on ColD
46- 52 F7.1 10+20cm-2 ColD Hydrogen column density
55 A1 --- n_ColD Flag indicating ColD and p_ColD is a
range
58- 64 F7.1 10+20cm-2 E_ColD ? Upper limit on ColD
67- 74 F8.1 10+20cm-2 e_ColD ? Lower limit on ColD
76 A1 --- f_ColD [d] Indicates parameter is pegged at
lower limit
78 A1 --- l_EW Lower limit on EW
79- 83 I5 eV EW ? Iron Kα line equivalent width
85- 90 I6 eV E_EW ? Upper limit on EW
93- 98 I6 eV e_EW ? Lower limit on EW
100 A1 --- n_EW Flag indicating line in EW is at 6.7 KeV
103-108 F6.4 10-11mW/m2 Fxo Observed flux between 2-10 KeV
112-118 F7.4 10-11mW/m2 Fxc Absorption corrected flux between
2-10 KeV
120 A1 --- n_Fxc Flag indicating Fxc is the lower value
124-127 F4.2 10-11mW/m2 E_Fxc ? Upper absorption corrected flux
between 2-10 KeV
130-131 I2 --- r_Name References in refs.dat
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Note (1):
e = Compton-thick source with NH=>1025cm-2
g = Compton-thick source with NH=>1024cm-2
h = X-ray emission possibly dominated by a cooling flow around
F09104+4109 (Fabian & Crawford, 1995MNRAS..274L..63F) and by
intracluster emission in Cygnus A (Ueno+, 1994ApJ..431L..1U)
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 2 I2 --- Seq Sequence number from table1.dat
5- 23 A19 --- Bibcode Reference code sequence
26-140 A115 --- Com Comments on references
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History:
From ApJ electronic edition
(End) Greg Schwarz (AAS) 01-Feb-2000