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Further evidence that 1RXS J170849.0-400910 is an Anomalous X-ray pulsar

GianLuca Israel·Stefano Covino·Luigi Stella·Sergio Campana·Sandro Mereghetti
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Abstract

We report the results of two ROSAT HRI observations of the recently discovered 11s X-ray pulsar 1RXS J170849.0-400910. A refined position with a smaller error radius (10" uncertainty) and a new spin period measurement were obtained. These results allowed to derive a period derivative of about 7 times 10^-4 s yr^-1 and to perform a photometric and spectroscopic study of the possible optical counterparts of the source. The limits derived from the optical to X-ray flux ratio exclude the presence of a massive OB companion. These findings, together with the nearly constant X-ray flux, the stability of the pulse shape and pulsed fraction across observations spanning three years, strongly support the inclusion of this 11s pulsar in the class of Anomalous X-ray Pulsars (AXPs).

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GianLuca Israel, Stefano Covino, Luigi Stella, Sergio Campana, Sandro Mereghetti. 1999-04-16. Further evidence that 1RXS J170849.0-400910 is an Anomalous X-ray pulsar. https://doi.org/10.1086/312077

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