Abstract Details

Name: Ketan Rikame
Affiliation: CHRIST (Deemed to be University)
Conference ID: ASI2021_601
Title : Discovery of Quasi Periodic Oscillations in the Accreting Binary X-ray Pulsar LMC X-4
Authors and Co-Authors : Ketan Rikame (Raman Research Institute, Bangalore; CHRIST (Deemed to be University), Bangalore), Biswajit Paul (Raman Research Institute, Bangalore), Pragati Pradhan (MIT Kavli Institute for Astrophysics and Space Research), KT Paul (CHRIST (Deemed to be University), Bangalore)
Abstract Type : Poster
Abstract Category : Stars, ISM and Galaxy
Abstract : We report for the first time, the discovery of quasi-periodic oscillations (QPOs) in the High Mass X-ray Binary (HMXB) pulsar LMC X-4 in its non-flaring (persistent) state using observations with XMM-Newton. In addition to the 74 mHz coherent pulsations, the steady-state light curve shows a QPO feature in the frequency range of 20-30 mHz. QPOs in X-ray binaries are generally thought to be related to the rotation of the inner accretion disk. Any inhomogeneous matter distribution or blobs of material in the inner disk may result in QPOs in the power spectrum. In HMXBs such as LMC X-4 where the compact object is a neutron star with a high magnetic field, the radius of the inner accretion disk is determined by the mass accretion rate and the magnetic moment of the neutron star. As the accretion disk can’t exist inside the magnetosphere, the radius of the inner accretion disk is equal to the radius of the magnetosphere. Assuming the beat frequency model for the QPOs and a Keplerian disk, the radius of the inner accretion disk can be determined from the observed QPO frequency. We use the X-ray luminosity and the magnetospheric radius to have an approximate value of the magnetic field strength of the neutron star in LMC X-4. Key words: X-ray Binaries, Neutron Stars, Accretion Disk, Quasi Periodic Oscillations, LMC X-4