Unravelling the Mystery of Cosmic Baby: Triaxiality and Resolving the Companion Identification Problem of GW190814

Authors: Parui RK*

DOI: 10.23880/oaja-16000129

Volume 2, Issue 2

Abstract

Detection of Gravitational wave opens a new window to see the insights of Binary Systems. Using gravitational waves the secondary or companion object of binary system GW190814 has been detected which has estimated mass 2.5 – 2.67 M⊙. A puzzle is created on its identification i.e., whether it was a heaviest neutron star or lowest mass black hole or any other compact object. Taking into account the three important facts in the evolution of the (BH – NS) binary: • Consistency of no EM counterpart detection constrains neutron star surface magnetic field to ≲1015 G; • The case of joint GW detection and EM upper limit rule out the theoretical possibilities that Neutron Stars in GW 200105, GW200115, and GW 190814 retain the surface dipolar magnetic fields ≳1015 G until merger; • Rule out the formation scenario where strongly magnetized neutron stars (i.e. magnetar) quickly merge with Black Hole. I calculate the internal magnetic field and ellipticity of the companion compact object magnetar (i.e. neutron star) before marge with Black Hole in the event GW190814 are 1.861516 x 1018 G, 1.00696 x 10-3 and 3.4597071 x 1018 G, 2.218239 x 10-2, respectively for optimistic and pessimistic cases. The estimated ellipticity values of the magnetar lies within the range 10-3 – 10-2 satisfying for becoming a triaxial star. Based on these findings this author suggests that the companion compact object of GW190814 was a “triaxial star”.

Keywords: Gravitational Waves; Neutron Star; Magnetar; Triaxial Star

View PDF