Study of emission behavior and pulse profile characteristics of a magnetar

Abstract

AnomalousX-RayPulsars(AXPs)areyoungneutronstarshavingamassofabout1.4M� withrotation periods of (2-12 s). They shows spin down behaviour with spin down rate ( 10−10- 10−13 s B−1) and typically X-ray luminosity’s about (L- 1033- 1036 erg B−1). These X-ray objects were thought to be young isolated neutron stars with ultra-strong magnetic fields (10−13 G, as determined by their spin and spin-down rates) known as " Magnetars " and powered entirely by the decay of this intense internal magnetic field. In this project, we present a study of the temporal and spectral behavior of one of the brightest magnetars, 4U 0142+61, using observations taken by the Large Area X-Ray Proportional Counter (LAXPC) & Soft X-ray Telescope onboard AstroSat on 10 January 2016 and 26 January 2016. In order to determine the timing solution of this magnetar, we also analyzed observations taken by the NICER telescope onboard the International Space Station (ISS) from July 2017 to January 2022. To understand the possible emission behavior, mechanisms, and emission regions, we studied the source spectrum in soft and intermediate X-ray bands (4-25 KeV). We determined the spin period (P) of the source and studied the pulse profile and evolution of pulse profile parameters e.g. pulse fraction, and amplitude using long-term timing studies in order to probe the magnetic field of this source and its complex morphologies. In the future, we intend to study the spectral behavior of this magnetar using data from NICER observations in order to better understand the complex behaviors of magnetars.