Jet and accretion-disk emission untangled in 3C 273

Science

Volumn 306, Issue 5698, 2004, Pages 998-1002

  Grandi, Paola ^a   Palumbo, Giorgio G C ^b  

^a Ist Astrofis Spaziale Fis Cosmica   (Italy)

^b UNIVERSITY OF BOLOGNA   (Italy)

Author keywords

[No Author keywords available]

Indexed keywords

DATA ACQUISITION; DATA REDUCTION; FLUID DYNAMICS; HEAT RADIATION;

ACCRETION FLOW; NONTHERMAL RADIATION;

JETS;

ASTROPHYSICS;

ARTICLE; ENERGY EXPENDITURE; FIELD EMISSION; FLAME PHOTOMETRY; PRIORITY JOURNAL; RADIATION; RADIATION ENERGY; SPECTROSCOPY; X RAY DIFFRACTION;

EID: 8344224532     PISSN: 00368075     EISSN: None     Source Type: Journal    
DOI: 10.1126/science.1101787     Document Type: Article

References (36)

1. G. Boella et al., Astron. Astrophys. 122, 299 (1997).
2. B. J. Wilkes, M. Elvis, Astrophys. J. 323, 243 (1987).
3. T. J. Turner et al., Astrophys. J. 381, 85 (1991).
4. J. L. Masnou et al., Astron. Astrophys. 253, 35 (1992).
5. T. J.-L. Courvoisier et al., Astron. Astrophys. 176, 197 (1987).
6. M. J. L. Turner et al., Mon. Not. R. Astron. Soc. 244, 310 (1990).
7. C. M. Leach et al., Mon. Not. R. Astron. Soc. 272, 221 (1995).
8. R. Walter et al., Astron. Astrophys. 285, 119 (1994).
9. P. Buhler et al., Astron. Astrophys. 295, 309 (1995).
10. O. R. Williams et al., Astrophys. J. 389, 157 (1992).
11. A. J. Lawson, M. J. L. Turner, Mon. Not. R. Astron. Soc. 288, 920 (1997).
12. M. Cappi et al., Publ. Astron. Soc. Jpn. 50, 213 (1998).
13. T. Yaqoob, P. Serlemitsos, Astrophys. J. 544, L95 (2000).
14. J. N. Reeves, M. J. L. Turner, Mon. Not. R. Astron. Soc. 316, 234 (2000).
15. P. Grandi et al., Astron. Astrophys. 325, L17 (1997).
16. F. Haardt et al., Astron. Astrophys. 340, 35 (1998). See (32).
17. A. Orr et al., Astron. Astrophys. 337, 685 (1998).
18. J. Kataoka et al., Mon. Not. R. Astron. Soc. 336, 932 (2002).
19. K. L. Page et al., Mon. Not. R. Astron. Soc. 349, 57 (2004).
20. G. G. Lichti et al., Astron. Astrophys. 298, 711 (1995).
21. F. Fiore, M. Guainazzi, P. Grandi, Cookbook for BeppoSAX NFI Spectral Analysis (1999), available at www.asdc.asi.it/bepposax/software/cookbook.
22. Spectra of the Low-Energy Concentrator Spectrometer (LECS, 0.15 to 3 keV) and the Medium-Energy Concentrator Spectrometer (MECS, 1.5 to 10 keV) were accumulated in 4′ radius circles. The background spectra were extracted from blank sky fields in the position of the source with the same extraction regions. The MECS instrument consisted of three units (1). MECS unit 1 data, available only in 1996 and 1997, were not included in the average spectrum, obtained by merging all nine BeppoSAX pointings. In single observation studies, MECS 1 data were used, when available. The Phoswich Detection System (PDS, 15 to 200 keV) used rocking collimators pointing on and off source to monitor the background. The net source spectra were produced by subtracting the background from the source data. Particle background events were rejected through the standard (fixed rise time) analysis, in agreement with the Cookbook for BeppoSAX NFI Spectral Analysis (21) prescriptions.
23. 2 test. The significance level of a model was obtained from the F test. An F probability greater than 99% implied a significant improvement of the fit.
24. P. Magdziarz, A. Zdziarski, Mon. Not. R. Astron. Soc. 273, 837 (1995).
25. M. H. Ulrich, T. J.-L. Courvoisier, W. Wamsteker, Astron. Astrophys. 204, 21 (1988).
26. G. C. Perola et al., Astron. Astrophys. 389, 802P (2002).
27. N. I. Shakura, R. A. Sunyaev, Astron. Astrophys. 24, 337 (1997).
28. F. Haardt, L. Maraschi, Astrophys. J. 380, L51 (1991).
29. F. Haardt, L Maraschi, Astrophys. J. 413, S07 (1993).
30. J. Poutanen, R. Svensson, Astrophys. J. 470, 249 (1996).
31. M. Dovciak et al., Mon. Not. R. Astron. Soc. 350, 745 (2004).
32. Haardt ef al. (16) also reported a first Indication of a steepening of the spectrum above 20 keV.
33. K. A. Arnaud, Asp. Conf. Ser. 101, 17 (1996).
34. J. M. Dickey, F. J. Lockman, Annu. Rev. Astmn. Astrophys. 28, 21S (1990).
35. P. Grandi, M. Cuainazzi, 3C 273 BeppoSAX-ASCA intercalibration (1990), available at www.asdc.asi.it/bepposax/software/cookbook.
36. The authors thank M. Fiocchi for helping with the data reduction and M. Cappi, M. Dadina, L. Foschini, and C. Mataguti for discussions and constructive criticism. Thanks are also due to L. Amati for helping with a problem in statistics. Financial support from the Italian Space Agency (ASI/n.045) and Ministero Università Ricerca Scientifica Tecnologica is gratefully acknowledged. G.G.C.P. gratefully acknowledges CNRS and the Centre d'Etude Spatial de Rayonnement in Toulouse for hospitality and partial financial support.