The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies
X-ray luminosities and spectral indices of 97 bright Seyfert 1 (Sy1) galaxies from the XMM-Newton archive are analysed in this article. Distribution of these values is random, so we conclude that the model of emission should be at least two-parametric. Within the framework of the merging model of ac...
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Головна астрономічна обсерваторія НАН України
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| Цитувати: | The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies / V.A. Sadova, A.V. Tugay // Advances in Astronomy and Space Physics. — 2015. — Т. 5., вип. 2. — С. 79-83. — Бібліогр.: 22 назв. — англ. |
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irk-123456789-1199362017-06-11T03:03:50Z The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies Sadova, V.A. Tugay, A.V. X-ray luminosities and spectral indices of 97 bright Seyfert 1 (Sy1) galaxies from the XMM-Newton archive are analysed in this article. Distribution of these values is random, so we conclude that the model of emission should be at least two-parametric. Within the framework of the merging model of active galactic nuclei (AGN), the relation between black hole mass, stage of merging and observable X-ray parameters is roposed. 2015 Article The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies / V.A. Sadova, A.V. Tugay // Advances in Astronomy and Space Physics. — 2015. — Т. 5., вип. 2. — С. 79-83. — Бібліогр.: 22 назв. — англ. 2227-1481 DOI:10.17721/2227-1481.5.79-83 http://dspace.nbuv.gov.ua/handle/123456789/119936 en Advances in Astronomy and Space Physics Головна астрономічна обсерваторія НАН України |
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English |
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X-ray luminosities and spectral indices of 97 bright Seyfert 1 (Sy1) galaxies from the XMM-Newton archive are analysed in this article. Distribution of these values is random, so we conclude that the model of emission should be at least two-parametric. Within the framework of the merging model of active galactic nuclei (AGN), the relation between black hole mass, stage of merging and observable X-ray parameters is roposed. |
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Article |
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Sadova, V.A. Tugay, A.V. |
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Sadova, V.A. Tugay, A.V. The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies Advances in Astronomy and Space Physics |
| author_facet |
Sadova, V.A. Tugay, A.V. |
| author_sort |
Sadova, V.A. |
| title |
The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies |
| title_short |
The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies |
| title_full |
The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies |
| title_fullStr |
The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies |
| title_full_unstemmed |
The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies |
| title_sort |
luminosity - spectral index dependence of the x-ray bright seyfert galaxies |
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Головна астрономічна обсерваторія НАН України |
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2015 |
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http://dspace.nbuv.gov.ua/handle/123456789/119936 |
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The luminosity - spectral index dependence of the X-ray bright Seyfert galaxies / V.A. Sadova, A.V. Tugay // Advances in Astronomy and Space Physics. — 2015. — Т. 5., вип. 2. — С. 79-83. — Бібліогр.: 22 назв. — англ. |
| series |
Advances in Astronomy and Space Physics |
| work_keys_str_mv |
AT sadovava theluminosityspectralindexdependenceofthexraybrightseyfertgalaxies AT tugayav theluminosityspectralindexdependenceofthexraybrightseyfertgalaxies AT sadovava luminosityspectralindexdependenceofthexraybrightseyfertgalaxies AT tugayav luminosityspectralindexdependenceofthexraybrightseyfertgalaxies |
| first_indexed |
2025-07-08T16:56:18Z |
| last_indexed |
2025-07-08T16:56:18Z |
| _version_ |
1837098630610157568 |
| fulltext |
The luminosity � spectral index dependence
of the X-ray bright Seyfert galaxies
V.A. Sadova, A.V.Tugay∗
Advances in Astronomy and Space Physics, 5, 79-83 (2015)
V.A. Sadova, A.V.Tugay, 2015
Taras Shevchenko National University of Kyiv, Glushkova ave., 4, 03127, Kyiv, Ukraine
X-ray luminosities and spectral indices of 97 bright Seyfert 1 (Sy1) galaxies from the XMM-Newton archive are
analysed in this article. Distribution of these values is random, so we conclude that the model of emission should be
at least two-parametric. Within the framework of the merging model of active galactic nuclei (AGN), the relation
between black hole mass, stage of merging and observable X-ray parameters is proposed.
Key words: X-rays: galaxies, galaxies: Seyfert
introduction
The XMM-Newton observation archive is the
largest and the most convenient database for the
analysis of the X-ray spectra of any celestial bod-
ies including the extragalactic ones. The Xgal sam-
ple of X-ray galaxies [15, 18] contains more than
4000 XMM sources associated with the galaxies or
galaxy clusters. The main goal of compiling Xgal was
the study of the large-scale structure (LSS) of the
Universe in the X-ray band (0.2�15 keV for XMM-
Newton). The distribution of the main elements of
LSS � �laments, voids and walls � can be recov-
ered for the redshifts up to 0.2 [14, 17]. It was shown
in [16, 19] that the most frequent type of X-ray emit-
ting galaxies at such distances is the Seyfert 1 (Sy1).
The spectra of the Sy1 galaxies in the Sloan Digi-
tal Sky Survey (SDSS) region were analysed in [16].
30 of them are Compton thin (NH < 1025 cm−2)
and thus their spectra can be correctly �tted with
the power law model. The remaining X-ray bright
Sy1 galaxies with the radial velocities from 4000 to
39000 km/s are studied in present work. We com-
piled a list of the most powerful X-ray galaxies in the
nearby Universe � the Compton thin Sy1 galaxies.
Our goal was to calculate the spectral parameters
of these galaxies, to build their distributions and to
identify some realistic connection between the ob-
served spectral parameters and the properties of the
internal structure of AGNs.
sample selection
and X-ray spectral analysis
The statistics of the galaxies considered in this
work is the following. There are 582 bright X-ray ex-
tragalactic sources outside of the SDSS region. 87 of
them are Sy1. The resulting list of bright Sy1 galax-
ies from the Xgal sample consists of three parts:
1. 30 Sy1 galaxies in the SDSS region, for which
the spectral parameters were obtained previously
in [16].
2. 23 galaxies with the spectra built in the present
work using the standard XMM SAS package. We get
event lists for the PN camera with the epproc proce-
dure, �ltered them from the solar protons using the
parameters 150 < PI < 15000 and PATTERN=0 and
derived the spectra with the especget procedure.
Background region was selected from the same CCD
chip as the source and of the same size.
3. 46 galaxies with the spectra found in the lit-
erature. 33 of them were from CAIXA (Catalog of
AGNs in the XMM-Newton Archive [3]).
Fig. 1: X-ray parameters of the Sy1 galaxies analysed
here. The lower, long-dashed line marks the mass of
the central black hole MBH = 107M⊙; for the upper,
short-dashed line the black hole mass is 109M⊙.
The parameters of the Sy1 galaxies from p.2 and
p.3, except for the CAIXA entries, are presented in
∗tugay.anatoliy@gmail.com
79
Advances in Astronomy and Space Physics V.A. Sadova, A.V.Tugay
Tables 1 and 2. The main observable parameters of
the X-ray emission are the luminosity and the spec-
tral index. In most cases of the Compton thin Sy1
galaxies these are the only parameters that can be
�tted correctly. The distribution of these parame-
ters is presented in Fig. 1. Another important spec-
tral feature in the 2�15 keV energy band is the iron
emission line at 6.5 keV, but it is rarely detected, so
we do not consider it here. Also we �nd two galaxies
where the thermal component dominates the emis-
sion: 2E1891 and IRAS05218-1212. We found the
best-�t blackbody temperatures of 1.11 ± 0.03 keV
and 2.37 ± 0.13 keV for these galaxies respectively.
The power law component was not �tted correctly
for these galaxies, so they were excluded from fur-
ther analysis.
interpretation of the X-ray
luminosity and spectral index
The previously analysed parameters should be
connected to some intrinsic parameters of the AGNs.
In the model of Hopkins et al. [8] an AGN appears as
a result of the collision and merger of two galaxies.
Di�erent observable features of that AGN can be in-
terpreted as stages of merging. This model suggests
a simple relation of the photon index and the time
since the collision:
Γ = log(t/106years).
It was assumed here that at large times after merger
the hard X-ray emission decreases that could appear
as an increase of the spectral index. Since the central
engine of an AGN is assumed to be a supermassive
black hole in its centre, the luminosity of that AGN
should correlate with the black hole mass. Taking
into account the decrease of the luminosity with the
age, the following formula for estimating the black
hole mass is proposed:
log(MBH/M⊙) = logLX + Γ−A, (1)
where LX is measured in erg/s. The physical mean-
ing of Eq. (1) lies in the assumption that the total
amount of the emitted energy (LX · t) should be re-
lated to the total energy budget of the source (or
the mass of the available gas, which should be pro-
portional to MBH). This relation, however, has not
yet been veri�ed and may have unclear systematical
uncertainty behind. The coe�cient A = 37.375 was
selected to equalise the average black hole mass with
the results of a similar work of Vestergaard & Peter-
son [21] (hereafter VP), where the black hole masses
for AGNs were also estimated from the X-ray emis-
sion. The averaged logarithm of the black hole mass
in [21] and for our sample equals (the uncertainty
corresponds to the 1σ con�dence level):
log(MBH/M⊙) = 7.992± 0.562. (2)
The two lines corresponding to the black hole
mass of 107M⊙ and 109M⊙ are shown in Fig. 1. The
derived in this way masses of the central black holes
of individual galaxies are presented in the last col-
umn of Table 2. The uncertainty of log(MBH/M⊙)
depends on the uncertainties of Γ, LX and the sys-
tematic e�ects. According to Eq. (2), this uncer-
tainty should be approximately equal to 0.5 or less.
The black hole mass distributions for our sample and
VP galaxies were approximated by Gaussian. Devi-
ation for the Xgal Sy1 galaxies appears somewhat
larger than in [21] � σ = 0.826. This value is po-
tentially biased, as here we study solely the X-ray
bright objects, whereas the VP sample, based on the
optical data, includes both the X-ray bright and dim
sources. The distributions of the black hole masses
for our sample and the VP results are presented in
Table 3. The percentage of the normal Gaussian dis-
tribution is also given for the comparison. The bin
width is equal to one standard deviation.
conclusion and discussion
The distribution of the X-ray emission parame-
ters in Fig. 1 is random, so we conclude that the
emission model of the studied galaxies should be at
least two-parametric. We propose to consider the
black hole mass and the merging stage as such in-
trinsic model parameters. The dependence of the
X-ray spectral index on the X-ray luminosity was
recently found in [22]. The authors considered the
dependence of Γ on LX/LEdd ratio and interpreted
this dependence as a two-phase advection dominated
accretion. In such study LEdd and the black hole
mass should be estimated independently from lumi-
nosity (for the method of the MBH estimation based
on the AGN X-ray emission see, e. g. [9]). This
is possible if the data on the X-ray variability are
available and the same source shows di�erent val-
ues of Γ and LX/LEdd in the series of observations.
The major part of Xgal objects has only one XMM
observation available and all the X-ray lightcurves
for our Sy1 galaxies are constant. So we can not
consider Γ(LX/LEdd) dependence and conclude here
that there is no signi�cant dependence of Γ on LX.
acknowledgement
This work was performed at VIRGO.UA. The
authors are thankful to the ISDC High-Energy
Astrophysics Data Centre for developing the
Ukrainian Virtual Roentgen and Gamma Observa-
tory. A.Tugay thanks to anonymous referee for use-
ful comments.
references
[1] BallantyneD.R., FabianA.C. & IwasawaK. 2004, MN-
RAS, 354, 839
[2] BallantyneD.R. 2005, MNRAS, 362, 1183
80
Advances in Astronomy and Space Physics V.A. Sadova, A.V.Tugay
[3] Bianchi S., BonillaN. F., GuainazziM., MattG. &
PontiG. 2009, A&A, 501, 915
[4] CorralA., BarconsX., Carrera F. J., CeballosM.T. &
Mateos S. 2005, A&A, 431, 97
[5] Croston J.H., HardcastleM. J., BirkinshawM. & Wor-
rall D.M. 2003, MNRAS, 346, 1041
[6] Gallo L.C., Lehmann I., PietschW. et al. 2006, MNRAS,
365, 688
[7] HardcastleM. J., Sakelliou I. & Worrall D.M. 2005, MN-
RAS, 359, 1007
[8] HopkinsP. F., Hernquist L., CoxT. J. & Kere²D. 2008,
ApJS, 175, 356
[9] Jang I., GliozziM., HughesC. & TitarchukL. 2014, MN-
RAS, 443, 72
[10] LewisK.T., EracleousM., GliozziM., SambrunaR.M. &
MushotzkyR. F. 2005, ApJ, 622, 816
[11] SambrunaR.M., Reeves J.N. & BraitoV. 2007, ApJ,
665, 1030
[12] SinghV., Shastri P. & Risaliti G. 2011, A&A, 532, A84
[13] Torresi E., Grandi P., Longinotti A. L. et al. 2010, MN-
RAS, 401, L10
[14] TugayA.V. 2013, Advances in Astronomy and Space
Physics, 3, 116
[15] TugayA.V. 2012, Odessa Astronomical Publications, 25,
142
[16] TugayA.V. 2013, Astronomical School's Report, 9, 64
[17] TugayA.V. 2014, Advances in Astronomy and Space
Physics, 4, 42
[18] TugayA.V. 2014, IAU Symp., 304, 168
[19] TugayA.V. & VasylenkoA.A. 2011, Odessa Astronom-
ical Publications, 24, 72
[20] VasylenkoA.A., ZhdanovV. I. & FedorovaE.V. 2015,
Ap&SS, 360, 37
[21] VestergaardM. & PetersonB.M. 2006, ApJ, 641, 689
[22] YangQ.-X., Xie F.-G., YuanF. et al. 2015, MNRAS, 447,
1692
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Advances in Astronomy and Space Physics V.A. Sadova, A.V.Tugay
Table 1: General parameters of the new Seyfert 1 galaxies added to the analysis. The rest of the sample see in [16]. u
is the u-band apparent magnitude; r is a major semiaxis of the 25m/′′ contour; V3K is the radial velocity in the CMB
reference frame. The parameters were taken from the Hyperleda database.
N Name RA, deg DEC, deg Coord. num. u r, arcsec V3K , km/s
1 2MASX J00044124+0007113 1.1718 0.1198 0004+0007 18.63 6.3 31923
2 ESO 540-1 8.5571 −21.4389 0034-2126 13.71 37.8 7744
3 2MASX J00440466+0101531 11.0195 1.0313 0044+0101 17.77 9.3 33210
4 2MASX J00565517-7513524 14.2297 −75.2312 0056-7513 15.04 6.4 22137
5 Mrk 993 21.3812 32.1360 0125+3208 14.37 47.6 4380
6 3C 59 31.7590 29.5128 0207+2930 17.44 11.1 32612
7 UGC 1841 35.7989 42.9914 0223+4259 13.75 65.7 6167
8 2MASX J02491286-0815254 42.3036 −8.2571 0249-0815 16.64 14.0 8617
9 ESO 359-19 61.2570 −37.1876 0405-3711 15.52 17.3 16476
10 3C 111 64.5885 38.0266 0418+3801 19.75 10.0 15305
11 Mrk 1506 68.2962 5.3542 0433+0521 15.06 23.3 9839
12 ESO 15-11 68.8183 −78.0323 0435-7801 15.58 20.3 18351
13 RBS 560 69.3672 −47.1916 0437-4711 16.61 7.4 15574
14 UGC 3142 70.9449 28.9718 0443+2858 15.84 28.0 6434
15 Pictor A 79.9570 −45.7789 0519-4546 16.25 14.7 10516
16 IRAS 05218-1212 81.0288 −12.1693 0524-1210 15.70 7.6 14721
17 2E 1644 95.7820 −64.6060 0623-6436 17.06 15.0 36197
18 2MASX J07185777+7059209 109.7410 70.9891 0719+7059 17.40 5.9 19810
19 2E 1891 119.5000 39.3414 0754+3928 15.21 2.0 28935
20 Sextans Ring 150.5010 −8.1614 0959-0809 15.22 13.0 4910
21 MCG +11-19-030 239.2650 63.8408 1557+6350 15.42 20.8 9000
22 2MASX J16115141-6037549 242.9640 −60.6319 1611-6037 14.70 26.7 4777
23 2MASX J16174561+0603530 244.4400 6.0649 1617+0603 16.19 14.4 11479
24 Mrk 883 247.4700 24.4439 1629+2426 15.78 18.1 11447
25 2E 4097 278.7640 32.6964 1835+3241 15.15 21.2 17289
26 FRL 339 302.9930 −57.0868 2011-5705 16.12 14.4 16274
27 4C 74.26 310.6560 75.1341 2042+7508 15.33 2.0 31071
28 Mrk 509 311.0410 −10.7235 2044-1043 13.35 17.7 10045
29 2MASX J21022164+1058159 315.5900 10.9711 2102+1058 14.92 12.6 8336
30 2MASX J22191855+1207531 334.8270 12.1315 2219+1207 17.19 8.3 24229
31 3C 445 335.9570 −2.1036 2223-0206 17.26 8.9 16510
32 NGC 7469 345.8150 8.8739 2303+0852 12.90 41.4 4545
33 NGC 7589 349.5650 0.2612 2318+0015 15.23 28.7 8578
34 NGC 7603 349.7360 0.2440 2318+0014 14.04 36.1 8484
35 NGC 7720 354.6230 27.0317 2338+2701 13.43 45.4 8695
36 MCG -05-01-013 359.3665 −30.4613 2357-3027 14.96 16.9 8744
82
Advances in Astronomy and Space Physics V.A. Sadova, A.V.Tugay
Table 2: X-ray parameters of the studied Sy1 galaxies. FX is the X-ray �ux in the 2�10 keV band in units of
10−14 erg/s/cm−2; LX40 is the X-ray luminosity in the redshift space, computed for H = 70 km/s/Mpc and divided
by 1040 erg/s; Γ is the spectral index; NH is the neutral hydrogen column density; for the spectra �tted in this work
the χ2/d.o.f. value is given instead of the reference.
N Target FX ∆FX LX40 Γ ∆Γ NH , 10
20cm−2 Ref. log(MBH/M⊙)
1 0004+0007 45.6 1.9 1080 1.840 0.098 0.013±0.011 28.46/29 7.873 ±0.233
2 0034-2126 80.1 2.2 112 1.440 0.100 [6] 6.489 ±0.235
3 0044+0101 110.5 8.7 2831 1.806 0.174 0.063±0.027 74.98/34 8.258 ±0.309
4 0056-7513 557.0 14.6 6339 2.118 0.056 0.046±0.008 113.13/61 8.920 ±0.191
5 0125+3208 216.6 3.4 96 1.710 0.060 0.07±0.01 [4] 6.694 ±0.195
6 0207+2930 1434.4 4.5 35428 1.398 0.006 0.0013±0.0007 4765.6/998 8.947 ±0.141
7 0223+4259 50.4 1.4 45 0.870 0.200 [5] 5.518 ±0.335
8 0249-0815 65.3 4.2 113 2.041 0.151 0.013±0.015 18.07/23 7.094 ±0.286
9 0405-3711 612.4 7.9 3861 1.764 0.019 0±0.006 28.12/17 8.351 ±0.154
10 0418+3801 8202.2 17.5 44619 1.700 0.020 0.8 [10] 9.349 ±0.155
11 0433+0521 8159.1 16.0 18343 1.860 0.010 0.01±0.001 [1] 9.122 ±0.145
12 0435-7801 251.9 4.2 1970 1.894 0.050 0.051±0.008 78.48/65 8.188 ±0.185
13 0437-4711 1203.9 5.6 6781 2.247 0.097 0±0.001 598.7/248 9.078 ±0.232
14 0443+2858 2179.5 16.2 2095 0.985 0.029 1.217±0.045 498.34/211 7.307 ±0.164
15 0519-4546 1784.9 4.7 4584 1.800 0.010 0.03±0.01 [20] 8.461 ±0.145
16 0524-1210 454.4 8.6 2287 9.500 9.900 0.909±0.464 143.54/28 -
17 0623-6436 818.0 8.4 24890 2.034 0.025 0.021±0.003 246.18/213 9.430 ±0.160
18 0719+7059 147.5 12.3 1344 1.971 0.235 0.024±0.045 2.15/5 8.098 ±0.490
19 0754+3928 382.1 5.0 7429 7.372 0.621 0.234±0.043 396.04/40 -
20 0959-0809 1078.5 6.7 604 2.432 0.023 0.066±0.002 783.18/540 8.213 ±0.158
21 1557+6350 50.7 6.0 95 2.082 0.206 0±0.072 5.77/5 7.061 ±0.476
22 1611-6037 907.8 27.7 481 1.712 0.059 0.131±0.016 67.21/56 7.394 ±0.194
23 1617+0603 1596.9 14.6 4887 1.957 0.017 0.021±0.002 535.78/495 8.646 ±0.152
24 1629+2426 287.9 4.2 876 1.689 0.054 0.103±0.014 53.73/57 7.632 ±0.189
25 1835+3241 6930.5 24.1 48110 2.150 0.180 3±1 [13] 9.832 ±0.315
26 2011-5705 296.9 3.8 1826 2.576 0.062 0.039±0.006 94.80/67 8.838 ±0.197
27 2042+7508 3857.2 10.0 86479 1.860 0.010 0.183 [2] 9.797 ±0.145
28 2044-1043 8290.5 10.2 19427 1.970 0.010 0.27±0.01 [20] 9.258 ±0.145
29 2102+1058 154.8 17.6 250 1.736 0.108 0.131±0.025 28.12/17 7.134 ±0.376
30 2219+1207 466.2 4.1 6356 3.099 0.019 0.074±0.002 523.61/233 9.902 ±0.154
31 2223-0206 875.2 12.0 5540 1.4 0.1 1 � 10 [11] 8.143 ±0.235
32 2303+0852 5311.5 14.5 2548 1.980 0.010 45±2 [20] 8.387 ±0.145
33 2318+0015 71.2 2.7 122 1.768 0.093 0.036±0.021 11.84/21 6.854 ±0.228
34 2318+0014 4597.2 32.9 7685 2.280 0.030 14.8±5.6 [12] 9.165 ±0.165
35 2338+2701 62.9 12.1 110 2 0.5 0.5±0.2 [7] 7.041 ±0.905
36 2357-3027 1060.8 46.5 1884 2.455 0.028 0.096±0.002 401.5/302 8.729 ±0.163
Table 3: Distribution of the black hole masses. The intervals are measured in standard deviations.
Interval < −3 (−3,−2) (−2,−1) (−1, 0) (0, 1) (1, 2) (2, 3) > 3
Number of galaxies 1 2 14 28 37 15 0 0
% 1.0 2.1 14.4 28.9 38.1 15.5 0 0
Number of galaxies in [21] 1 0 1 12 13 5 0 0
% 3.1 0 3.1 37.5 40.6 15.6 0 0
Normal distribution. % 0.2 2.1 15.6 32.1 32.1 15.6 2.1 0.2
83
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