Chromothermal oscillations and collapse of strange stars to black holes: astrophysical implications

Abstract

We study the effects of temperature on strange stars. It is found that the maximum mass of the star decreases with the increase of temperature, as at high temperatures the equations of state become softer. Moreover, if the temperature of a strange star increases, keeping its baryon number fixed, its gravitational mass increases and its radius decreases. This leads to a limiting temperature, where it turns into a black hole. These features are the result of a combined effect of the change of gluon mass and the quark distribution with temperature. We report on a new type of radial oscillation of strange stars, driven by what we call ‘chromothermal’ instability. We also discuss the relevance of our findings in the astrophysics of core collapse supernovae and gamma‐ray bursts.

A Three‐Stage Model for the Inner Engine of Gamma‐Ray Bursts: Prompt Emission and Early Afterglow

“…This point denotes an instability, and so if there is accretion onto a star having this maximum mass, it collapses into a black hole. We note, however, that thermally induced instabilities can drive the collapse to a black hole before reaching the Chandrasekhar limit (for details, see Bagchi et al 2006).…”

“…This process operates in three steps: (1) The quark nova (Ouyed et al 2002), where the core is converted to quark matter resulting in mass ejection. (2) Fall-back material from the supernova together with some of the matter ejected during the quark nova can form an accretion disk around the quark star.…”

r-Java 2.0: the astrophysics

“…Our focus of this application of r-Java 2.0 is to consider the Quark-Nova (henceforth QN) as just one of several possible ejection mechanisms for neutron star material. First proposed by as a means to power the central engine of gamma-ray bursts, it has since been developed in more detail (Keränen & Ouyed 2003;Keränen et al 2005) and discussed in many contexts such as GRBs (Ouyed & Sannino 2002;Ouyed et al 2005;Staff et al 2008), magnetic field decay of AXPs and SGRs (Niebergal et al 2006;Koning et al 2013), collapse to black holes (Bagchi et al 2008), ultra-luminous SNe (Leahy & Ouyed 2008;Ouyed et al 2012b) and reionization from the first stars (Ouyed et al 2009). The QN converts gravitational energy and nuclear binding energy partly into internal energy (heat) and partly into kinetic energy, with the majority energy release taken by neutrinos.…”