EDP Sciences
Free Access
Volume 391, Number 2, August IV 2002
Page(s) 571 - 576
Section Formation, structure and evolution of stars
DOI https://doi.org/10.1051/0004-6361:20020778

A&A 391, 571-576 (2002)
DOI: 10.1051/0004-6361:20020778

XMM-Newton observations of the isolated neutron star RX J0806.4-4123

F. Haberl and V. E. Zavlin

Max-Planck-Institut für extraterrestrische Physik, Giessenbachstraße, 85748 Garching, Germany
(Received 3 April 2002 / Accepted 16 May 2002)

The isolated neutron star was observed with XMM-Newton in November 2000. The data from the three EPIC instruments allowed us (i) to derive an improved X-ray position to an accuracy of 2-3´´, (ii) to accumulate the first medium-resolution soft X-ray spectra of high statistical quality and (iii) to find a candidate for the neutron star rotation period. Although this period of 11.3714 s is formally detected at a 3.5 $\sigma$ level in the EPIC-pn data, the similar pulse profiles deduced from all three EPIC instruments increase the confidence that the period is real. The pulsed fraction of ~6% would then be the weakest X-ray flux modulation detected from dim isolated neutron stars. We fitted the X-ray spectra with blackbody and neutron star atmosphere models and discuss the results with respect to the brightness limit placed by optical images. The reduced size of the error circle on the X-ray position should allow deeper searches for an optical counterpart.

Key words: X-rays: stars -- stars: neutron -- stars: magnetic fields -- stars: individual:

Offprint request: F. Haberl, fwh@mpe.mpg.de

© ESO 2002