No significant change in the radio flux density of PSR B1259-63/LS 2883 near the 2022 apastron
ATel #15923; M. E. Lower (CSIRO), S. Johnston (CSIRO)
on 2 Mar 2023; 04:25 UT
Credential Certification: Marcus Lower (marcus.lower@csiro.au)
Subjects: Radio, Variables, Pulsar
Referred to by ATel #: 15942
The pulsar-binary system PSR B1259-63/LS 2883 has been regularly monitored using Murriyang, the 64-m Parkes radio telescope, as part of the Parkes young pulsar timing programme over the last 16 years (Weltevrede et al. 2010, PASA 27 64). As of 2019, our observations have been performed with the Parkes Ultra-Wideband Low receiver system providing continuous frequency coverage from 704-4032 MHz (Hobbs et al. 2020, PASA 37 e012). We use observations of a linearly polarised noise diode and on-/off-pointings of the radio galaxies PKS 0407-658 and PKS 1934-638 to correct for the absolute gain and phase of the system. The polarimetric response of the instrument as a function of parallactic angle is determined using matrix equivalent template matching on a rise-to-set scan of PSR J0437-4715.
Following ATel #15920 we computed the pulsar flux density across a subband covering 707-957 MHz using the method outlined in Lower et al. (2021, MNRAS 502 127). Ignoring non-detections during observations around the February 2021 periastron passage, we measure a mean flux density of 5.4 +/- 1.2 mJy. The measurements since the previous periastron passage show the normal type of flux density variability due to refractive scintillation and are unlikely to be caused by interactions with the intra-binary medium. There is no evidence for any excess flux density. ATel #15920 reports a circular polarisation fraction which is consistent with the 18.1 percent fractional circular polarisation in the pulse profile (Johnston and Kerr 2018, MNRAS 474 4629).
The Parkes radio telescope (Murriyang) is part of the Australia Telescope National Facility which is funded by the Australian Government for operation as a National Facility managed by CSIRO. We acknowledge the Wiradjuri people as the traditional owners of the Observatory site.
