Discovery of X-ray pulsations from the integral source IGR J11014-6103

We report the discovery of PSR J1101-6101, a 62.8 ms pulsar in IGR J11014-6103, a hard X-ray source with a jet and a cometary tail that strongly suggests it is moving away from the center of the supernova remnant (SNR) MSH 11-61A at v > 1000 km s^-1. Two XMM-Newton observations were obtained with the EPIC pn in small window mode, resulting in the measurement of its spin-down luminosity erg s^-1, characteristic age τ_c = 116 kyr, and surface magnetic field strength B_s = 7.4 × 10¹¹ G. In comparison to τ_c , the 10-30 kyr age estimated for MSH 11-61A suggests that the pulsar was born in the SNR with initial period in the range 54 ≤ P ₀ ≤ 60 ms. PSR J1101-6101 is the least energetic of the 15 rotation-powered pulsars detected by INTEGRAL, and has a high efficiency of hard X-ray radiation and jet power. We examine the shape of the cometary nebula in a Chandra image, which is roughly consistent with a bow shock at the velocity inferred from the SNR age and the pulsar's . However, its structure differs in detail from the classic bow shock, and we explore possible reasons for this.