Abstract Details

Name: Sushan Konar
Affiliation: National Centre for Radio Astrophysics
Conference ID: ASI2021_593
Title : The Curious Case of Nulling Pulsars
Authors and Co-Authors : Sushan Konar, Jayanta Roy, Bhaswati Bhattacharyya NCRA-TIFR, Pune
Abstract Type :
Abstract Category : Stars, ISM and Galaxy
Abstract : Radio pulsars are strongly magnetized rotating neutron stars characterized by short spin periods ($P \sim 10^{-3} - 10^2$~s) and large inferred surface magnetic fields ($B \sim 10^8 - 10^{15}$~G). Powered by the loss of rotational energy, they emit coherent radiation in narrow emission pulses. Abrupt cessation of this pulsed emission for several pulse periods, observed in a small subset, is known as nulling. It has been suggested that nulling pulsars are likely to be close to the death line, being active only when favourable conditions prevail. A comprehensive list of nulling pulsars has recently been compiled by Konar & Deka (2019). The data appears to suggest that pulsars with extremely curved magnetic fields and for which the emission comes predominantly from the polar cap are likely to experience nulling episodes. Because these nulling pulsars are bounded (in the spin-period -- magnetic field plane) by the death-line corresponding to such conditions. However, there exist quite a few active radio pulsars in the surrounding region of this death line which are not known to have experienced nulling episodes. Since pulsars in this region are slow objects with no apparent significance they have mostly not been studied in detail. However, it is quite clear that if these objects are carefully monitored, we would have a direct and definitive indication of the conclusion drawn in the above work. With this in mind, we have also initiated a program, of targeted observation of slow pulsars in the above mentioned region with the Giant Meterwave Radio Telescope (Konar, Roy, Bhattacharya 2020).--------------------------------------------- 1. Radio Pulsar Sub-Populations (I) : The Curious Case of Nulling Pulsars, Sushan Konar & Uddeepta Deka, Astrophys. Astron. (2019) 40, 42 2. An investigation into nulling pulsars, Sushan Konar, Jayanta Roy & Bhaswati Bhattacharyya, GMRT Proposal, Cycle-38 (2020), observation completed