1997A&A...326..885B


Query : 1997A&A...326..885B

1997A&A...326..885B - Astronomy and Astrophysics, volume 326, 885-896 (1997/10-3)

UV to X-ray spectra of radio-quiet quasars. Comparison with accretion disk models.

BRUNNER H., MUELLER C., FRIEDRICH P., DOERRER T., STAUBERT R. and RIFFERT H.

Abstract (from CDS):

We present UV to soft X-ray spectra of 31 radio-quiet quasars, comprising data from the IUE ULDA database and the ROSAT pointed observation phase. 90 % of the sample members show a soft X-ray excess above an underlying hard X-ray power law spectrum. Particularly for the steep X-ray spectrum (αenergy>1.5), low redshift subsample (17 objects) the X-ray spectral power law index is strongly correlated with the optical to X-ray broad-band spectral index αox, indicating that the main contribution to the soft X-ray and optical emission is due to the same emission component. We model the UV/soft X-ray spectra in terms of thermal emission from a geometrically thin α-accretion disk. The structure and radiation field of the disk is calculated self-consistently and Compton scattering is treated by the Kompaneets equation. All relativistic effects on the disk structure and the emergent disk spectrum are included. Satisfactory spectral fits of the UV and soft X-ray continuum spectra are achieved when additional non-thermal hard X-ray and IR power law emission components are taken into account. The UV and soft X-ray spectra are well described by emission resulting from accretion rates in the range ∼0.1 to ∼0.3 times the Eddington accretion rate. Low mass/low redshift objects are found to accret at <0.15{dot}(M)Eddington. Correlations of the accretion disk parameters with αox are discussed.

Abstract Copyright:

Journal keyword(s): accretion disks - active galaxies - quasars - X-rays: galaxies - ultraviolet: galaxies

Simbad objects: 32

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Number of rows : 32
N Identifier Otype ICRS (J2000)
RA
ICRS (J2000)
DEC
Mag U Mag B Mag V Mag R Mag I Sp type #ref
1850 - 2022
#notes
1 LEDA 1790 Sy1 00 29 13.7012449608 +13 16 03.947778264   15.70 15.41     ~ 414 0
2 LEDA 3237 Sy1 00 54 52.1183662680 +25 25 38.983241532     15.42     ~ 357 0
3 Ton S 210 QSO 01 21 51.5142110136 -28 20 57.799968396   15.38 15.19     ~ 91 0
4 Mrk 1014 Sy1 01 59 50.2534701768 +00 23 40.864244784   16.08 15.87     ~ 536 0
5 Mrk 586 Sy1 02 07 49.8619039200 +02 42 55.876760568   15.67 15.41     ~ 188 0
6 2MASS J08105865+7602424 Sy1 08 10 58.6641543864 +76 02 42.450451260   15.03 14.71     ~ 439 0
7 [VV96] J091609.5-621929 Sy1 09 16 09.3662148312 -62 19 29.562130128   12.51 12.26 11.5   ~ 122 0
8 HE 1029-1401 Sy1 10 31 54.3173785536 -14 16 51.378102372   14.08 13.86     ~ 119 0
9 PG 1049-005 Sy1 10 51 51.4474066944 -00 51 17.707987476   15.98 15.78     ~ 165 0
10 PG 1101-264 QSO 11 03 25.2993421704 -26 45 15.808554720   16.08 16.02     ~ 240 0
11 Ton 1388 Sy1 11 19 08.6786220240 +21 19 17.987085948   14.91 14.80     ~ 437 0
12 LEDA 38224 Sy1 12 04 42.1097215992 +27 54 11.869350264   15.64 15.60     ~ 367 0
13 PG 1216+069 Sy1 12 19 20.9318278680 +06 38 38.467059252   15.68 15.65     ~ 267 0
14 LB 19 QSO 12 50 05.7146863848 +26 31 07.598352000   16.12 15.92     ~ 195 0
15 [B68b] 201 QSO 12 59 48.7852053336 +34 23 22.627553928   17.05 16.79     ~ 96 0
16 LEDA 45656 Sy1 13 09 47.0031619008 +08 19 48.212362524   16.04 15.89     ~ 364 0
17 Ton 1565 Sy1 13 12 17.7526981968 +35 15 21.086467128   15.45 15.64 14.2   ~ 255 1
18 LEDA 101275 Sy1 13 37 18.7199358192 +24 23 03.319883484     15.0     ~ 373 0
19 PB 4142 Sy1 13 54 35.6874184872 +18 05 17.504491992   16.84 16.68     ~ 209 0
20 QSO J1409+2618 QSO 14 09 23.9085820008 +26 18 21.056458176   16.07 15.74     ~ 184 0
21 LEDA 51016 Sy1 14 17 00.8224797456 +44 56 06.336360024   16.93 16.63     ~ 235 0
22 LEDA 51142 Sy1 14 19 03.8170514760 -13 10 44.785212600   16.46 16.10 16.50   ~ 224 0
23 2MASS J14464593+4035057 Sy1 14 46 45.9392259288 +40 35 05.797233636   16.28 16.11     ~ 274 0
24 QSO B1521+1009 QSO 15 24 24.5234088744 +09 58 29.087917572   15.74 16.2     ~ 121 0
25 QSO B1544+4855 Sy1 15 45 30.2358624864 +48 46 08.976390420   16.92 16.73     ~ 219 0
26 Mrk 876 Sy1 16 13 57.1795021224 +65 43 09.952685328   16.03 15.49     ~ 538 0
27 Mrk 877 Sy1 16 20 11.2799789400 +17 24 27.515242152   15.79 15.39     ~ 257 0
28 QSO B1630+3744 QSO 16 32 01.1117931960 +37 37 49.980505332   16.50 16.30     ~ 169 0
29 HS 1700+6416 QSO 17 01 00.6194059368 +64 12 09.118892376   16.39 16.17     ~ 360 0
30 ClG 1821+64 ClG 18 21 56.7276 +64 20 55.841           ~ 495 1
31 7C 1821+6419 Sy1 18 21 57.2130271440 +64 20 36.221312076   14.23 14.24     ~ 566 1
32 NAME MR 2251-178 Sy1 22 54 05.8858611984 -17 34 55.402233708   14.99 14.36 15.12   ~ 401 3

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2022.05.22-22:58:51

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