An XMM-Newton observation during the 2000 outburst of SAX J1808.4-3658

I present an XMM-Newton observation of the accretion-driven millisecond X-ray pulsar SAX J1808.4-3658 during its 2000 outburst. The source was conclusively detected, albeit at a level of only similar to2 x 10(32) ergs s(-1). The source spectrum could be fitted with a power-law model ( with a photon index of similar to2.2), a neutron star atmosphere model ( with a temperature of similar to0.2 keV), or a combination of a thermal (either a blackbody or an atmosphere model) and a power-law component. During an XMM-Newton observation taken approximately 1 yr later, the source was in quiescence, and its luminosity was a factor of similar to4 lower. It is possible that the source spectrum during the 2000 outburst was softer than its quiescent 2001 spectrum; however, the statistics of the data do not allow a firm conclusion. The results obtained are discussed in the context of the 2000 outburst of SAX J1808.4-3658 and the quiescent properties of the source.