Status update on double pulsar: Multi-frequency multi-epoch observations with GMRT
Bhal Chandra Joshi
National Centre for Radio Astrophysics, TIFR, Pune
E-mail: bcj@ncra.tifr.res.in

Abstract. The double pulsar system, J0737-3039, a highly relativistic binary system with two radio pulsars (periods ∼23 ms and 2.8 s), is an excellent system to study the gravity theories, processes in pulsar magnetosphere and the effects of geodetic precession on the observed pulse emission. It is a highly relativistic binary system with two radio pulsars in a tight edge-on mildly eccentric orbit with a significant advance of angle of periastron (orbital period 2.4 hr, orbital inclination angle 87.7 deg, eccentricity 0.09). PSR J0737-3039A exhibits a double peaked profile independent of orbital phase with different spectral index for the two components, while PSR J0737-3039B exhibits a narrow profile, in two windows centered on orbital longitudes 210 and 280 deg (Lyne et al. 2004), called bright phase 1 and bright phase 2. Both profiles evolve significantly with observation frequency. The time-scale for geodetic precession is a factor of 4 shorter than that for Hulse-Taylor pulsar, PSR B1913+16, allowing these effects to be detected in a short time. Indeed, significant effects have been reported since the discovery of this system and in most recent observations with Giant Metrewave Radio Telescope (GMRT). A report on monitoring of this system at multiple frequencies and epochs with GMRT is presented and the implications of the results are discussed. An update on the current status of the research on this system is presented. In particular, the fading away of PSR J0737-3039B is reported.