Strange quark star I: the maximum gravitational mass and deformation of magnetized spinning model

TL;DR

This study models strange quark stars considering strong magnetic fields and rotation, revealing maximum masses over 2.3 solar masses and significant deformation, aligning with observed compact objects.

Contribution

It introduces a variable-density MIT bag model with Landau quantization to analyze the structure and maximum mass of magnetized, rotating strange quark stars.

Findings

Maximum gravitational mass exceeds 2.3 M_sun.

Deformation parameter reaches up to 1.55.

Maximum mass of 2.8 M_sun in fast-rotating models.

Abstract

We investigate the structural parameters of strange quark stars (SQS) under the influence of strong magnetic fields and varying rotational frequencies. The equation of state is computed using the MIT bag model with a density-dependent bag constant and considering the Landau quantization effect regarding the strong magnetic fields up to $5\times10^{17}\,$G in the interior of SQS. Employing the LORENE library, we calculate the structural parameters under different magnetic field strengths and rotational frequencies. Our models are compared in terms of maximum gravitational mass, deformation parameter, binding energy, and compactness. Our equation of state model demonstrates that the gravitational masses are higher than those computed using a MIT bag model with a fixed bag constant. We find the gravitational masses beyond $2.3 \,M_\odot$, which are compatible with the masses of observed compact objects, such as the ``black widow'' pulsar \emph{PSR J0952-0607}, and the \emph{GW190814} event detected by the LIGO/Virgo collaboration. The deformation parameter and maximum gravitational mass of SQS are characterized by fitted functions accounting for variations in both magnetic field strength and rotational frequency. We find the maximum deformation parameter of 1.55 and the maximum gravitational mass of $2.8\, M_\odot$ in the fast-rotating strongly magnetized model.