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Spectral and temporal properties of the X-ray pulsar SMC X-1 at hard X-raysThe binary X-ray pulsar SMC X- 1 has been observed at hard X-rays with the High Energy X-Ray Experiment (HEXE) on nine occasions between Nov. 1987 and March 1989. A thin thermal bremsstrahlung fit to the phase averaged spectrum yields a plasma temperature (14.4 +/- 1.3) keV and a luminosity above (1.1 +/- 0.1) x 10 exp 38 erg/s in the 20-80 keV band. Pulse period values have been established for three observations, confirming the remarkably stable spin-up trend of SMC X-1. In one of the three observations the pulse profile was seen to deviate from a dominant double pulsation, while at the same time the pulsed fraction was unusually large. For one observation we determined for the first time the pulsed fraction in narrow energy bands. It increases with photon energy from about 20 percent up to over 60 percent in the energy range from 20 to 80 keV.
Document ID
19940035082
Document Type
Reprint (Version printed in journal)
Authors
Kunz, M. (Tuebingen Univ. Germany)
Gruber, D. E. (California Univ. San Diego, United States)
Kendziorra, E . (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Kretschmar, P. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Maisack, M. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Mony, B. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Staubert, R. (Tuebingen Univ. Germany)
Doebereiner, S. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Englhauser, J. (NASA Goddard Space Flight Center Greenbelt, MD, United States)
Pietsch, W. (Max-Planck-Inst. fuer Extraterrestrische Physik Garching, Germany)
Date Acquired
August 16, 2013
Publication Date
February 1, 1993
Publication Information
Publication: Astronomy and Astrophysics
Volume: 268
Issue: 1
ISSN: 0004-6361
Subject Category
ASTROPHYSICS
Funding Number(s)
CONTRACT_GRANT: DFG-ST-175/11-2
CONTRACT_GRANT: DFG-ST-175/11-3
CONTRACT_GRANT: DFG-ST-175/11-4DFG-ST-175/11-5
CONTRACT_GRANT: DFG-ST-175/11-1
CONTRACT_GRANT: NAG5-1372
Distribution Limits
Public
Copyright
Other