Abstract Details
| Name: Jayanta Roy Affiliation: NCRA-TIFR Conference ID: ASI2018_1642 Title : J1227-4853 a transitional millisecond pulsar probing neutron star at crossroad Authors and Co-Authors : Paul Ray (NRL) and Bhaswati Bhattacharyya (NCRA-TIFR) Abstract Type : Poster Abstract Category : Stars,ISM and the Galaxy Abstract : Low-mass X-ray binaries (LMXBs) and radio millisecond pulsars (MSPs) are linked through stellar and binary evolution, where MSPs are end products of an episode of accretion of matter and angular momentum from the binary companion during the LMXB state. Over the last decade, the discovery of three transitional millisecond pulsars (tMSPs) has allowed detailed study of recycling process. Recent studies of PSR J1824−2452I (Papitto et al. 2013) and PSR J1023+0038 (Stappers et al. 2013; Takata et al. 2013; Patruno et al. 2014) have observationally demonstrated the LMXB – MSP evolutionary link. These systems show direct evidence of back-and-forth state switching between radio MSP and accreting X-ray millisecond pulsar regimes and opened a new avenue of research in pulsar astrophysics. Third such tMSP system, J1227-4853, was discovered by us using the GMRT (Roy et al. 2015). I will present the results from the radio and gamma-ray study of this pulsar for last 3 years, while highlighting a broad overview of tMSPs as a class and as laboratories to observationally map the hitherto unexplored evolutionary phase of MSPs. Simultaneous imaging and time-domain analysis for PSR J1227-4853 to directly probe the cause of eclipse will also be discussed. J1227-4853 a 1.69 millisecond pulsar at a dispersion measure of 43.4 pc cm$^{-3}$, transited into the active radio-MSP phase associated with sudden drop of its X-ray and optical luminosity. Systematic GMRT-Fermi-LAT timing campaigns over the last 3 years have provided detection of gamma-ray pulsations from this tMSP. Extreme orbital perturbations as well as signature of proper motion are revealed from the timing analysis. PSR J1227−4853 is the only transitioning system currently in an active rotation-powered state. With regular monitoring of the system with the GMRT, we are recently observing interesting changes in it's radio properties. We are in the process of understanding changes in radio properties in synergy with X-ray and gamma-ray properties of the source. Detailed study of such systems will help to determine whether these transitional systems will eventually be canonical radio MSPs or whether they will form a new sub-class of MSPs that will continue to transition back- and-forth between the two states. Also, such studies will result in better understanding of the spin evolution of the systems and dynamics of accretion during accretion-powered, propeller stage and rotation-powered phases. |