Thin accretion disks around cold Bose-Einstein Condensate stars

TL;DR

This paper compares the electromagnetic and thermodynamic properties of thin accretion disks around Bose-Einstein Condensate stars, neutron stars, and quark stars to identify potential observational signatures distinguishing these compact objects.

Contribution

It provides a detailed comparative analysis of accretion disk properties around different compact stars, highlighting potential observational differences for the first time.

Findings

Differences in energy flux and temperature distribution among the stars.

Distinct electromagnetic spectra and efficiency of energy conversion.

Potential observational signatures to distinguish BEC stars from neutron/quark stars.

Abstract

Due to their superfluid properties some compact astrophysical objects, like neutron or quark stars, may contain a significant part of their matter in the form of a Bose-Einstein Condensate. Observationally distinguishing between neutron/quark stars and Bose-Einstein Condensate stars is a major challenge for this latter theoretical model. An observational possibility of indirectly distinguishing Bose-Einstein Condensate stars from neutron/quark stars is through the study of the thin accretion disks around compact general relativistic objects. In the present paper, we perform a detailed comparative study of the electromagnetic and thermodynamic properties of the thin accretion disks around rapidly rotating Bose-Einstein Condensate stars, neutron stars and quark stars, respectively. Due to the differences in the exterior geometry, the thermodynamic and electromagnetic properties of the disks (energy flux, temperature distribution, equilibrium radiation spectrum and efficiency of energy conversion) are different for these classes of compact objects. Hence in this preliminary study we have pointed out some astrophysical signatures that may allow to observationally discriminate between Bose-Einstein Condensate stars and neutron/quark stars, respectively.