XMM-Newton Observation of the Nearby Pulsar B1133+16

We constrain the X-ray properties of the nearby (360 pc), old (5 Myr) pulsar B1133+16 with similar to 100 ks effective exposure time by XMM-Newton. The observed pulsar flux in the 0.2-3 keV energy range is similar to 10(-14) erg cm(-2) s(-1), which. results in the. recording of similar to 600 source counts with the EPIC pn and MOS detectors. The X-ray radiation is dominated by nonthermal radiation and is well described by both a single power-law model (PL) and a sum of blackbody and power-law emission (BB+PL). The BB+PL model results in a spectral photon index Gamma = 2.4(-0.3)(+0.4) and a nonthermal flux in the 0.2-3 keV energy range of. (7 +/- 2) x 10(-15)erg cm(- 2) s(-1). The thermal emission is consistent with the blackbody emission from a small hot spot with a. radius of R-pc approximate to 14(-5)(+7) m and a temperature of T-s = 2.9(-0.4)(+0.6) MK. Assuming that the hot spot corresponds to the polar cap of the pulsar, we can use the magnetic flux conservation law to estimate the magnetic field at the surface B-s approximate to 3.9 x 10(14) G. The observations are in good agreement with the predictions of the partially screened gap model, which assumes the existence of small-scale surface magnetic field structures in the polar cap region.