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Discovery of SAX J1753.5-2349 and SAX J1806.5-2215: two X-ray bursters without detectable steady emission

J. J. M. in 't Zand·J. Heise·J. M. Muller·A. Bazzano·M. Cocchi·L. Natalucci·P. Ubertini
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Abstract

We report the discovery with BeppoSAX-WFC of two new X-ray sources that were only seen during bursts: SAX J1753.5-2349 and SAX J1806.5-2215. For both sources, no steady emission was detected above an upper limit of 5 mCrab (2 to 8 keV) for 3 10**5 s around the burst events. The single burst detected from SAX J1753.5-2349 shows spectral softening and a black body color temperature of 2.0 keV. Following the analogy with bursts in other sources the burst very likely originates in a thermonuclear flash on a neutron star. The first of two burst detected from SAX J1806.5-2215 does not show spectral softening and cannot be confirmed as a thermonuclear flash.

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J. J. M. in 't Zand, J. Heise, J. M. Muller, A. Bazzano, M. Cocchi, L. Natalucci, P. Ubertini. 1998-02-24. Discovery of SAX J1753.5-2349 and SAX J1806.5-2215: two X-ray bursters without detectable steady emission. https://doi.org/10.1016/s0920-5632(98)00214-x

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