2014ApJ...790..103A

We report on XMM-Newton EPIC observations of the young pulsar J2022+3842, with a characteristic age of 8.9 kyr. We detected X-ray pulsations and found the pulsation period P ~ 48.6 ms, and its derivative {dot}P = 8.6 x 10^–14, which is two times larger than previously reported values. The pulsar exhibits two very narrow (FWHM ∼1.2 ms) X-ray pulses each rotation, separated by ~0.48 of the period, with a pulsed fraction of ~0.8. Using the correct values of P and {dot}P, we calculate the pulsar's spin-down power {dot}E = 3.0 x 10³⁷ erg/s and magnetic field B = 2.1x10¹² G. The pulsar spectrum is well modeled with a hard power-law (PL) model (photon index Γ = 0.9±0.1, hydrogen column density n_H= (2.3±0.3)x10²²/cm2). We detect a weak off-pulse emission, which can be modeled with a softer PL (Γ ~ 1.7±0.7), that is poorly constrained because of contamination in the EPIC-pn timing mode data. The pulsar's X-ray efficiency in the 0.5-8 keV energy band, n_PSR = L_PSR/{dot}E = 2 x 10^–4(D/10 kpc)², is similar to those of other pulsars. The XMM-Newton observation did not detect extended emission around the pulsar. Our re-analysis of Chandra X-ray Observatory archival data shows a hard, Γ ~ 0.9±0.5, spectrum and a low efficiency, η_PWN∼ 2x10^–5(D/10 kpc)², for the compact pulsar wind nebula, unresolved in the XMM-Newton images.