Discovery of nine gamma-ray pulsars in Fermi Large Area Telescope data using a new blind search method

Abstract

We report the discovery of nine previously unknown gamma-ray pulsars in a blind search of data from the Fermi Large Area Telescope (LAT). The pulsars were found with a novel hierarchical search method originally developed for detecting continuous gravitational waves from rapidly rotating neutron stars. Designed to find isolated pulsars spinning at up to kHz frequencies, the new method is computationally efficient and incorporates several advances, including a metric-based gridding of the search parameter space (frequency, frequency derivative, and sky location) and the use of photon probability weights. The nine pulsars have spin frequencies between 3 and 12Hz, and characteristic ages ranging from 17kyr to 3Myr. Two of them, PSRs J1803-2149 and J2111+ 4606, are young and energetic Galactic-plane pulsars (spin-down power above 6 × 1035ergs-1 and ages below 100kyr). The seven remaining pulsars, PSRs J0106+4855, J0622+3749, J1620-4927, J1746-3239, J2028+3332, J2030+4415, and J2139+4716, are older and less energetic; two of them are located at higher Galactic latitudes (|b| > 10°). PSR J0106+4855 has the largest characteristic age (3Myr) and the smallest surface magnetic field (2 × 1011G) of all LAT blind-search pulsars. PSR J2139+4716 has the lowest spin-down power (3 × 1033ergs-1) among all non-recycled gamma-ray pulsars ever found. Despite extensive multi-frequency observations, only PSR J0106+4855 has detectable pulsations in the radio band. The other eight pulsars belong to the increasing population of radio-quiet gamma-ray pulsars. © 2012 The American Astronomical Society. All rights reserved.