Abstract
QUASARS normally exhibit only small fluctuations in brightness, but occasional instances of substantial variability have been used to constrain the size and geometry of the emitting region. Here we report a recent observation from the Ginga satellite1 of the quasar PKS0558–504, during which the X-ray flux increased by 67% in the space of only 3 minutes. There was no significant change in the spectrum. Comprehensive analysis of the data strongly indicates that this was a genuine X-ray flare originating in the quasar. The implied rate of change in luminosity in the 2–10 keV range, assuming a Hubble constant of 70 km s−1 Mpc−1 and a cosmological deceleration parameter q0 = 0.5, is 3.2 × 1042 erg s−2, the highest value measured for a quasar. When photon scattering is considered, this is ∼16 times greater than could be produced, with a 3-minute rise time, in an isotropically emitting plasma. We argue that the apparent luminosity must be enhanced by relativistic beaming. This is the first indication of beaming in an 'ordinary' unpolarized quasar.
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References
Makmo, F. et al. Astrophys. Lett. Comm. 25, 223–233 (1987).
Remillard, R. et al. Astrophys. J. 301, 742–752 (1986).
Remillard, R. Schwartz, D. A. & Brissenden, R. J. V. in A Decade of UV Astronomy with IUE (Eur. Space Ag. spec. Publ. 281) 273–275 (1988).
Malkan, M. Astrophys. J. 268, 582–590 (1983).
Turner, M. J. L. et al. Publ. astr. Soc. Japan 41, 345–372 (1989).
Hayashida, K. et al. Publ. astr. Soc. Japan 41, 373–389 (1989).
NOAA Solar-geophys. Data Prompt Reports 544, (ed. Coffey, H. E.) 10–11 (1989).
NOAA Solar-geophys. Data Prompt Reports 545, (ed. Coffey, H. E.) 138–140 (1990).
Ambruster, C. W., Sciortino, S. & Golub, L. Astrophys. J. Suppl. 65, 273–305 (1987).
Schwartz, D. A. et al. Mon. Not. R. astr. Soc. 196, 95–100 (1981).
Agrawal, P. C., Rao, A. R. & Streekantan, B. V. Mon. Not. R. astr. Soc. 219, 225–240 (1986).
Haisch, B. H. et al. Astrophys. J. 267, 280–290 (1983).
Connors, A. Serlemitsos, P. J. & Swank, J. H. Astrophys. J. 303, 769–779 (1986).
Griffiths, R. E. et al. in X-ray Astronomy (COSPAR) (eds Baity W. & Petersen, L.) 93–96 (Pergamon, New York, 1979).
Makino, F. et al. Astrophys. J. 347, L9–L12 (1989).
Barr, P. & Mushotzky, R. F. Nature 320, 421–423 (1986).
Urry, C. M. in Active Galactic Nucleic (eds Miller, R. J. & Wiita, P. J.) 257 (Springer, Berlin, 1988).
Feigelson, E. et al. Astrophys. J. 302, 337–351 (1986).
Fabian, A. C. in The Physics of Accretion onto Compact Objects (eds Mason, K. O. Watson, M. G. & White, N. E. ) 229–241 (Springer, Berlin, 1986).
Guilbert, P. W., Fabian, A. C. & Rees, M. J. Mon. Not. R. astr. Soc. 205, 593–603 (1983).
Matilsky, T., Shrader, C. & Tananbaum, H. Astrophys. J. 258, L1–L5 (1982).
Brissenden, R. J. V. B. thesis, Australian National University (1990).
Barthel P. D. Astrophys. J. 336, 606–611 (1989).
Unwm, S. C. et al. Astrophys. J. 340, 117–128 (1989).
Gabuzda, D. C., Wardle, J. F. C. & Roberts, D. H. Astrophys. J. 336, L59–L62 (1989).
Ghisellini, G. & Maraschi, L. Astrophys. J. 340, 181–189 (1989).
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Remillard, R., Grossan, B., Bradt, H. et al. A rapid energetic X-ray flare in the quasar PKS0558–504. Nature 350, 589–592 (1991). https://doi.org/10.1038/350589a0
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DOI: https://doi.org/10.1038/350589a0
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