Abstract Details

Name: Sanjay Kudale
Affiliation: National Centre for Radio Astrophysics
Conference ID: ASI2020_129
Title : Study of eclipses for Redback pulsar J1227-4853
Authors and Co-Authors : S Kudale, J. Roy, B. Bhattacharyya, B. Stappers, J. Chengalur
Abstract Type : Oral
Abstract Category : Stars, ISM and Galaxy
Abstract : We will present results from a study of the eclipses in the 3rd known transitional redback millisecond pulsar J1227-4853, which was discovered with the GMRT. Emission from this pulsar is eclipsed at 607 MHz for about 37% of its orbit around the superior conjunction. We also observe eclipse ingress and egress transitions for 12% and 15% of its orbit respectively, resulting in only 36% of orbit being free of any eclipsing effects. This makes PSR J1227-4853 one of the longest known eclipsing systems. The excess dispersion (DM) & electron column density (Ne) observed at the eclipse boundaries are also high compared to other known eclipsing binaries. From simultaneous dual-frequency observations we estimate the power-law index for frequency-dependent eclipse duration to be n <= -0.64. In addition to the superior conjunction, we also observe excess dispersion associated with fading of flux densities near the inferior conjunction, indicating that extreme intra-binary interactions result in occasional clustering of fragmented blobs of plasma around the inferior conjunction. From simultaneous timing and imaging studies we conclude eclipses in J1227-4853 are caused by absorption of the signal by intra-binary material rather than by temporal smearing due to excess dispersion and scattering.