Radio and gamma-ray timing of TRAPUM L-band Fermi pulsar survey discoveries

¹ INAF – Osservatorio Astronomico di Cagliari, Via della Scienza 5, I-09047 Selargius, (CA), Italy
² Max Planck Institute for Gravitational Physics (Albert Einstein Institute), D-30167 Hannover, Germany
³ Leibniz Universität Hannover, D-30167 Hannover, Germany
⁴ Max-Planck-Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany
⁵ South African Radio Astronomy Observatory, 2 Fir Street, Black River Park Observatory, Cape Town 7925, South Africa
⁶ Jodrell Bank Centre for Astrophysics, Department of Physics and Astronomy, The University of Manchester, Manchester M13 9PL, UK
⁷ National Astronomical Research Institute of Thailand, Don Kaeo, Mae Rim, Chiang Mai 50180, Thailand
⁸ LPC2E – Université d’Orléans/CNRS, 45071 Orléans cedex 2, France
⁹ Observatoire Radioastronomique de Nançay (ORN), Observatoire de Paris, Université PSL, Université d’Orléans, CNRS, 18330 Nançay, France
¹⁰ National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville, VA 22903, USA

^⋆ Corresponding author; marta.burgay@inaf.it

Received: 16 July 2024
Accepted: 26 September 2024

Abstract

This paper presents the results of a joint radio and gamma-ray timing campaign on the nine millisecond pulsars (MSPs) discovered as part of the L-band targeted survey of Fermi-LAT sources performed in the context of the Transients and Pulsars with MeerKAT (TRAPUM) Large Survey Project. Out of these pulsars, eight are members of binary systems; of these eight, two exhibit extended eclipses of the radio emission. Using an initial radio timing solution, pulsations were found in the gamma rays for six of the targets. For these sources, a joint timing analysis of radio times of arrival and gamma-ray photons was performed, using a newly developed code that optimises the parameters through a Markov chain Monte Carlo (MCMC) technique. This approach has allowed us to precisely measure both the short- and long-term timing parameters. This study includes a proper motion measurement for four pulsars, which a gamma ray-only analysis would not have been sensitive to, despite the 15-year span of Fermi data.