The first extragalactic ultra-compact X-ray binary: A candidate black hole-white dwarf system
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M31 UCXB-1 is one of the brightest X-ray point sources in the bulge of M31, with a peak X-ray luminosity L 0.5 - 10 keV = 2 . 9 - 0.2 + 0.2 × 10 38 erg s - 1 . Both XMM-Newton and Chandra observations have detected an eclipsing signal with a peri... ...
