Three Millisecond Pulsars in FERMI LAT Unassociated Bright Sources

TL;DR

This study discovered three millisecond pulsars in unassociated Fermi LAT sources, revealing their binary nature, gamma-ray emission, and typical X-ray luminosities, suggesting most radio MSPs are gamma-ray emitters.

Contribution

First detection of radio and gamma-ray millisecond pulsars in unassociated Fermi sources, highlighting their binary nature and gamma-ray emission characteristics.

Findings

All pulsars are in binary systems.

Pulsars are nearby, relatively normal MSPs.

Gamma-ray spectra show power-law with exponential cutoff.

Abstract

We searched for radio pulsars in 25 of the non-variable, unassociated sources in the Fermi LAT Bright Source List with the Green Bank Telescope at 820 MHz. We report the discovery of three radio and gamma-ray millisecond pulsars (MSPs) from a high Galactic latitude subset of these sources. All of the pulsars are in binary systems, which would have made them virtually impossible to detect in blind gamma-ray pulsation searches. They seem to be relatively normal, nearby (<=2 kpc) millisecond pulsars. These observations, in combination with the Fermi detection of gamma-rays from other known radio MSPs, imply that most, if not all, radio MSPs are efficient gamma-ray producers. The gamma-ray spectra of the pulsars are power-law in nature with exponential cutoffs at a few GeV, as has been found with most other pulsars. The MSPs have all been detected as X-ray point sources. Their soft X-ray luminosities of ~10^{30-31} erg/s are typical of the rare radio MSPs seen in X-rays.