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Title: DISCOVERY OF AN UNIDENTIFIED FERMI OBJECT AS A BLACK WIDOW-LIKE MILLISECOND PULSAR

Journal Article · · Astrophysical Journal Letters
; ;  [1]; ;  [2];  [3];  [4];  [5];  [6]; ; ;  [7]
  1. Institute of Astronomy and Department of Physics, National Tsing Hua University, Hsinchu 30013, Taiwan (China)
  2. Department of Physics, University of Hong Kong (Hong Kong)
  3. Department of Physics, Tokyo Institute of Technology 2-12-1, Ookayama, Meguro, Tokyo, 152-8551 (Japan)
  4. National Research Council Research Associate, National Academy of Sciences, Washington, DC 20001 (United States)
  5. CRESST and Astroparticle Physics Laboratory NASA/GSFC, Greenbelt, MD 20771 (United States)
  6. General Education Center, China Medical University, Taichung 40402, Taiwan (China)
  7. Research Institute for Science and Engineering, Waseda University, 3-4-1 Okubo, Shinjuku, Tokyo 169-8555 (Japan)

The Fermi {gamma}-ray Space Telescope has revolutionized our knowledge of the {gamma}-ray pulsar population, leading to the discovery of almost 100 {gamma}-ray pulsars and dozens of {gamma}-ray millisecond pulsars (MSPs). Although the outer-gap model predicts different sites of emission for the radio and {gamma}-ray pulsars, until now all of the known {gamma}-ray MSPs have been visible in the radio. Here we report the discovery of a 'radio-quiet' {gamma}-ray-emitting MSP candidate by using Fermi, Chandra, Swift, and optical observations. The X-ray and {gamma}-ray properties of the source are consistent with known {gamma}-ray pulsars. We also found a 4.63 hr orbital period in optical and X-ray data. We suggest that the source is a black widow-like MSP with a {approx}0.1 M{sub Sun} late-type companion star. Based on the profile of the optical and X-ray light curves, the companion star is believed to be heated by the pulsar while the X-ray emissions originate from pulsar magnetosphere and/or from intrabinary shock. No radio detection of the source has been reported yet, and although no {gamma}-ray/radio pulsation has been found we estimate that the spin period of the MSP is {approx}3-5 ms based on the inferred {gamma}-ray luminosity.

OSTI ID:
22048026
Journal Information:
Astrophysical Journal Letters, Vol. 747, Issue 1; Other Information: Country of input: International Atomic Energy Agency (IAEA); ISSN 2041-8205
Country of Publication:
United States
Language:
English