2024/07/15 by Bidisha Sen, M. Linares, Manuel Linares +12 · 1 voice · 1 citation
Physics and Astronomy · #Gamma-ray bursts and supernovae #Pulsars and Gravitational Waves Research #Stellar, planetary, and galactic studies #astro-ph.HE
paper · pdf · doi:10.3847/1538-4357/ad6314
arxiv published 2024/07/15 · arxiv updated 2024/07/15 · openalex publication_date 2024/09/25 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/03
Abstract The companion to PSR J1622-0315, one of the most compact known redback millisecond pulsars, shows extremely low irradiation despite its short orbital period. We model this system to determine the binary parameters, combining optical observations from the New Technology Telescope in 2017 and the Nordic Optical Telescope in 2022 with the binary modeling code ICARUS . We find a best-fit neutron star mass of 2.3 ± 0.4 M ⊙ , and a companion mass of 0.15 ± 0.02 M ⊙ . We detect for the first time low-level irradiation from asymmetry in the minima as well as a change in the asymmetry of the maxima of its light curves over five years. Using starspot models, we find better fits than those from symmetric direct heating models, with consistent orbital parameters. We discuss an alternative scenario where the changing asymmetry is produced by a variable intrabinary shock. In summary, we find that PSR J1622-0315 combines low irradiation with variable light-curve asymmetry and a relatively high neutron star mass.