New observational constraints on hard X-/γ-ray millisecond pulsar emission from 47 Tucanae
نویسنده
چکیده
Recent X-/γ-ray observations with the Rossi X-ray Timing Explorer (RXTE) of 47 Tuc (NGC 104) are used to compare different models of millisecond pulsar emission. Data from both the Proportional Counter Array and the High Energy X-ray Timing Experiment are presented, covering a total energy range of 2–250 keV. A new upper limit on the hard X-/γ-ray emission from 47 Tuc is set, suggesting that the isolated millisecond pulsars may be non–emitting or very weak X-ray sources. The current binary X-ray emission theory is consistent with this result with some modification. Timing analysis reveals no periodic pulsations in the data, further suggesting that isolated millisecond pulsars are very weak X-ray emitters.
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