Multiwavelength analysis of four millisecond pulsars

TL;DR

This study combines radio and gamma-ray observations to analyze four millisecond pulsars, revealing their emission properties, detecting gamma-ray pulsations, and modeling their light curves to understand their magnetospheric emission regions.

Contribution

It provides the first gamma-ray pulsation detections for two MSPs discovered via radio searches and offers multiwavelength analysis and modeling of four pulsars' emission characteristics.

Findings

Gamma-ray pulsations detected from PSR B1937+21 and B1957+20.

Radio searches discovered two new MSPs, PSRs J2017+0603 and J2302+4442.

Multiwavelength timing and spectral analysis performed on all four pulsars.

Abstract

Radio timing observations of millisecond pulsars (MSPs) in support of Fermi LAT observations of the gamma-ray sky enhance the sensitivity of high-energy pulsation searches. With contemporaneous ephemerides we have detected gamma-ray pulsations from PSR B1937+21, the first MSP ever discovered, and B1957+20, the first known black-widow system. The two MSPs share a number of properties: they are energetic and distant compared to other gamma-ray MSPs, and both of them exhibit aligned radio and gamma-ray emission peaks, indicating co-located emission regions in the outer magnetosphere of the pulsars. However, radio observations are also crucial for revealing MSPs in Fermi unassociated sources. In a search for radio pulsations at the position of such unassociated sources, the Nan\c{c}ay Radio Telescope discovered two MSPs, PSRs J2017+0603 and J2302+4442, increasing the sample of known Galactic disk MSPs. Subsequent radio timing observations led to the detection of gamma-ray pulsations from these two MSPs as well. We describe multiwavelength timing and spectral analysis of these four pulsars, and the modeling of their gamma-ray light curves in the context of theoretical models.