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New observational constraints on hard X-/-ray millisecond pulsar emission from 47 Tucanae
A.J. Bird and
Received 10 June 1999 / Accepted 30 August 1999
Recent X-/-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-/-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.
Key words: X-rays: stars stars: binaries: general stars: pulsars: general Galaxy: globular clusters: individual: 47 Tuc
Send offprint requests to: C. Ferguson
Online publication: October 14, 1999