Single-pulse analysis and average emission characteristics of PSR J1820-0427 from observations made with the MWA and uGMRT
Abstract
We have studied the pulse-to-pulse variability in PSR J1820-0427 and its frequency dependence using high-quality, wide-band observations made with the upgraded Giant Metrewave Radio Telescope (uGMRT; 300-750 MHz) and the Murchison Widefield Array (~170-200 MHz). The low-frequency data reveal a previously unreported feature in the average profile (at 185 MHz) after accounting for the effects of temporal broadening arising from multipath scattering due to the interstellar medium. We advance a new method for flux density calibration of beamformed data from the uGMRT and use it to measure the single-pulse flux densities across the uGMRT band. Combined with previously published measurements, these flux densities are best fitted with a power-law spectrum with a low-frequency turnover. We also use calibrated flux densities to explore the relationship between pulse-to-pulse variability and the spectral index of individual pulses. Our analysis reveals a large scatter in the single-pulse spectral indices and a general tendency for brighter pulses to show a steepening of the spectral index. We also examine the frequency dependence of the pulse fluence distribution and its relation to the Stochastic Growth Theory.
- Publication:
-
Monthly Notices of the Royal Astronomical Society
- Pub Date:
- August 2023
- DOI:
- 10.1093/mnras/stad1797
- arXiv:
- arXiv:2306.08050
- Bibcode:
- 2023MNRAS.523.5934J
- Keywords:
-
- (stars:) pulsars: general;
- (stars:) pulsars: individual: J1820-0427;
- Astrophysics - High Energy Astrophysical Phenomena;
- Astrophysics - Solar and Stellar Astrophysics
- E-Print:
- 13 pages, 9 figures, 2 tables. Accepted for publication in MNRAS