Searching for $\gamma$-ray emission from LOTAAS pulsars

TL;DR

This study searches for gamma-ray emissions from newly discovered LOTAAS pulsars using Fermi LAT data, finding one candidate and setting upper limits on others, suggesting most are unlikely detectable gamma-ray sources.

Contribution

First gamma-ray search for LOTAAS pulsars using Fermi LAT data, providing flux upper limits and candidate identification.

Findings

One candidate gamma-ray counterpart identified.

Most LOTAAS pulsars likely have low spin-down luminosities.

Upper limits suggest these pulsars are not detectable with current gamma-ray instruments.

Abstract

The LOw-Frequency ARray (LOFAR) has recently conducted a survey (LOFAR Tied-Array All-sky Survey; LOTAAS) for pulsars in the Northern hemisphere that resulted in discoveries of 73 new pulsars. For the purpose of studying the properties of these pulsars, we search for their $\gamma$-ray counterparts using the all-sky survey data obtained with the Large Area Telescope (LAT) onboard the Fermi Gamma-Ray Space Telescope (Fermi).We analyze the LAT data for 70 LOTAAS pulsars (excluding two millisecond pulsars and one with the longest known spin period of 23.5s). We find one candidate counterpart to PSRJ1017$+$30, which should be searched for the $\gamma$-ray pulsation signal once its timing solution is available. For other LOTAAS pulsars, we derive their 0.3--500GeV flux upper limits. In order to compare the LOTAAS pulsars with the known $\gamma$-ray pulsars, we also derive the 0.3--500GeV $\gamma$-ray fluxes for 112 of the latter contained in the Fermi LAT fourth source catalog.Based on the properties of the $\gamma$-ray pulsars, we derive upper limits on the spin-down luminosities of the LOTAAS pulsars. The upper limits are not very constraining but help suggest that most of the LOTAAS pulsars probably have $< 10^{33}$erg s$^{-1}$ spin-down luminosities and are not expected to be detectable with Fermi LAT.