2007A&A...467L..45E

We present the first X-ray detection of the very young pulsar PSR J1357-6429 (characteristic age of 7.3kyr) using data from the XMM-Newton and Chandra satellites. We find that the spectrum is well described by a power-law plus blackbody model, with photon index Γ=1.4 and blackbody temperature k_BT=160eV. For the estimated distance of 2.5kpc, this corresponds to a 2-10keV luminosity of ∼1.2x10³²erg/s, thus the fraction of the spin-down energy channeled by PSRJ1357-6429 into X-ray emission is one of the lowest observed. The Chandra data confirm the positional coincidence with the radio pulsar and allow to set an upper limit of 3x10³¹erg/s on the 2-10keV luminosity of a compact pulsar wind nebula. We do not detect any pulsed emission from the source and determine an upper limit of 30% for the modulation amplitude of the X-ray emission at the radio frequency of the pulsar.