| Name: | Sangita Kumari |
| Affiliation: | NCRA-TIFR pune |
| Conference ID : | ASI2023_659 |
| Title : | Probing the drastic changes in the frequency dependent eclipsing for PSR J1544+4937 |
| Authors : | Sangita Kumari, Bhaswati Bhattacharyya, Devojyoti Kansabanik, Jayanta Roy |
| Mode of Presentation: | Poster |
| Abstract Category : | Stars, ISM and Galaxy |
| Abstract : | We report very drastic changes in the eclipse cut-off frequency for the black widow pulsar J1544+4937. Majority of such systems often exhibit relatively long duration ~ 15% radio eclipses caused by ablated material from the companion stars (e.g. Polzin et al. 2020). The eclipse observed in such systems are frequency dependent and are more pronounced at lower frequencies (< 1.5 MHz). PSR J1544+4937 is a Fermi black-widow MSP with spin period 2.16 ms discovered by Giant Metrewave Radio Telescope (GMRT, Bhattacharyya et al. 2013). The previous studies reported an eclipse cut-off frequency of 345 MHz for a few epochs of observations for this system (Kansabanik et al. 2013). We observed a factor of two increase in the cut-off frequency for this system from our observations on 12th February 2022. Later follow-up observations showed that the cut-off frequency is changing with time. In this presentation we will report a systematic study of variation of eclipse cut-off frequency for about a decade, where we observed significant differences in the cut-off frequency values in a few day’s time scale. Such drastic variations in cut-off frequency is not reported for this system or any other spider millisecond pulsar system before. This shows that PSR J1544+4937 is clearly undergoing some kind of transition, where the eclipse environment is dynamically evolving over short timescales. These changes in the observed eclipse cut-off frequency could depict temporal changes of the magnetic field strength and electron density in the eclipse region. |
