Pointed RXTE observations of SAX J1808.4-3658

Wijnands, R.; Wolt, M. Klein; Linares, M.; van der Klis, M.; Chakrabarty, D.; Morgan, E. H.; Markwardt, C. B.
Bibliographical reference

The Astronomer's Telegram, #507

Advertised on:
6
2005
Number of authors
7
IAC number of authors
0
Citations
8
Refereed citations
4
Description
Follow-up RXTE PCA observations of the transient source consistent with the position of SAX J1808.4-3658 (ATEL#505) showed clear coherent pulsations at approximately 401 Hz. This frequency is identical to the spin frequency of the neutron star in SAX J1808.4-3658 demonstrating that it is indeed SAX J1808.4-3658 which is in outburst again. During the three pointed observations the 2-10 keV X-ray fluxes were approximately 19 mCrab on June 1, 17:35 - 18:42 UTC, 31 mCrab on June 2 00:13 - 00:51 UTC, and 34 mCrab on June 2 10:56 - 11:46 UTC indicating that the X-ray flux is still rising.