The first extragalactic ultra-compact X-ray binary: A candidate black hole-white dwarf system.

Qian-Qi Ma1, Jiachang Zhang2,3, Wei-Min Gu1

  • 1Department of Astronomy, Xiamen University, Xiamen, Fujian 361005, China.

Summary

M31 UCXB-1 is the brightest ultra-compact X-ray binary (UCXB) discovered, likely a black hole-white dwarf system. It exhibits the shortest orbital period and strongest gravitational wave emission among known UCXBs.

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