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Discovery of the Orbit of the X-ray pulsar OAO 1657-415Timing observations of the 38 s accreting X-ray pulsar OAO 1657-415 made with the BATSE large-area detectors on the Compton Gamma Ray Observatory have revealed a binary orbit with an X-ray eclipse by the stellar companion. From the pulsar mass function fx(M) = 11.7 +/- 0.2 solar masses and the measured eclipse half-angle theta(e) = 29.7 +/- 1.3 deg, we infer that the stellar companion is a supergiant of spectral class B0-B6. If the companion can be identified and its orbital velocity measured, the neutron star mass can be constrained. Both intrinsic spin-up and spin-down of the pulsar were measured during our observation.
Document ID
19930040000
Document Type
Reprint (Version printed in journal)
External Source(s)
Authors
Chakrabarty, Deepto (California Inst. of Technology Pasadena, United States)
Grunsfeld, John M. (California Inst. of Technology, Pasadena; NASA, Johnson Space Center Houston, TX, United States)
Prince, Thomas A. (NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Bildsten, Lars (California Inst. of Technology Pasadena, United States)
Finger, Mark H. (NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Wilson, Robert B. (NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Fishman, Gerald J. (NASA Lyndon B. Johnson Space Center Houston, TX, United States)
Meegan, Charles A. (NASA Marshall Space Flight Center Huntsville, AL, United States)
Paciesas, William S. (Alabama Univ. Huntsville, United States)
Date Acquired
August 16, 2013
Publication Date
January 20, 1993
Publication Information
Publication: Astrophysical Journal, Part 2 - Letters
Volume: 403
Issue: 1
ISSN: 0004-637X
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: NAG5-1458
CONTRACT_GRANT: NAGW-1919
CONTRACT_GRANT: NAGW-2920
Distribution Limits
Public
Copyright
Other