We are grateful to Ken Van Riper for providing us with the cooling curves in numerical form, to Dima Yakovlev for clarifying various aspects of the NS cooling, to Gordon Garmire for the discussion of X-ray observations of isolated NSs in SNRs, and to the anonymous referee whose critical remarks helped us to improve the paper. The ASCA data were obtained through the High Energy Astrophysics Science Archive Research Center Online Service, provided by the NASA/Goddard Space Flight Center. The work was partially supported through NASA grant NAG5-2807, NASA ADP grant, INTAS grant 94-3834 and DFG-RBRF grant 96-02-00177G. VEZ thanks the Pennsylvania State University for hospitality and acknowledges the Max-Planck fellowship.
© European Southern Observatory (ESO) 1998
Online publication: March 3, 1998