XMM-Newton Observations of Young and Energetic Pulsar J2022+3842

• Published in: arXiv.org 2014-06
• Main Authors: Arumugasamy, P, Pavlov, G G, Kargaltsev, O
• Format: Article
• Language: English
• Subjects: Emission analysis; Nebulae; Pulsars; Pulsation; Stellar winds; XMM (spacecraft)
• ISSN: 2331-8422
• DOI: 10.48550/arxiv.1406.2349

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 \(P\approx 48.6\) ms, and its derivative \(\dot{P}\approx 8.6\times 10^{-14}\), twice larger than the previously reported values. The pulsar exhibits two very narrow (FWHM \(\sim 1.2\) ms) X-ray pulses each rotation, separated by \(\approx 0.48\) of the period, with a pulsed fraction of \(\approx 0.8\). Using the correct values of \(P\) and \(\dot{P}\), we calculate the pulsar's spin-down power \(\dot{E}=3.0 \times 10^{37}\) erg s\(^{-1}\) and magnetic field \(B=2.1\times 10^{12}\) G. The pulsar spectrum is well modeled with a hard power-law (PL) model (photon index \(\Gamma = 0.9\pm0.1 \), hydrogen column density \(n_H = (2.3\pm0.3) \times 10^{22}\,{\rm cm}^{-2}\)). We detect a weak off-pulse emission which can be modeled with a softer PL (\(\Gamma \approx 1.7\pm0.7\)), 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, \(\eta_{\rm PSR}= L_{\rm PSR}/\dot{E} = 2 \times 10^{-4} (D/10\,{\rm kpc})^2\), 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, \(\Gamma \approx 0.9 \pm 0.5\), spectrum and a low efficiency, \(\eta_{\rm PWN}\sim 2\times 10^{-5} (D/10\,{\rm kpc})^2\), for the compact pulsar wind nebula, unresolved in the \(XMM-Newton\) images.