Article

# Quark Stars as inner engines for Gamma Ray Bursts?

(Impact Factor: 4.38). 03/2001; 387(2). DOI: 10.1051/0004-6361:20020409
Source: arXiv

ABSTRACT

A model for Gamma ray bursts inner engine based on quark stars (speculated to exist in nature) is presented. We describe how and why these objects might constitute new candidates for GRB inner engines. At the heart of the model is the onset of exotic phases of quark matter at the surface of such stars, in particular the 2-flavor color superconductivity. A novel feature of such a phase is the generation of particles which are unstable to photon decay providing a natural mechanism for a fireball generation; an approach which is fundamentally different from models where the fireball is generated during collapse or conversion of neutron star to quark star processes. The model is capable of reproducing crucial features of Gamma ray bursts, such as the episodic activity of the engine (multiple and random shell emission) and the two distinct categories of the bursts (two regimes are isolated in the model with \sim 2 s and \sim 81 s burst total duration). Comment: 8 pages, 3 figures, new and more appropriate title. Major changes in the text (aspects of the models discussed in more details), better quality Figure 1 and Figure 2 and added Figure 3, version to appear in Astronomy&Astrophysics

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Available from: Francesco Sannino, Nov 17, 2012
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##### Article: Quark-Nova
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ABSTRACT: We explore the scenario where the core of a neutron star (having experienced a transition to an up and down quark phase) shrinks into the equilibrated quark object after reaching strange quark matter saturation density (where a composition of up, down and strange quarks is the favored state of matter). The overlaying (envelope) material free-falls following the core contraction releasing upto 10^{53} {\rm ergs} in energy as radiation, partly as a result of the conversion of envelope material to quarks. This phenomena, we named Quark-Nova, leads to a wide variety of ejectae ranging form the Newtonian, "dirty" to the ultra-relativistic fireball. The mass range of the corresponding compact remnant (the quark star) ranges from less than 0.3M_{\odot} up to a solar mass. We discuss the connection between Quark-Novae and Gamma ray bursts and suggest the recently studied GRB011211 event as a plausible Quark-Nova candidate. Comment: 4 pages, 2 figures, shortened title. Major changes in the text, version to appear in Astronomy&Astrophysics
Preview · Article · May 2001 · Astronomy and Astrophysics
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##### Article: Gamma-Ray Bursts from Delayed Collapse of Neutron Stars to Quark Matter Stars
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ABSTRACT: We propose a model to explain how a Gamma Rays Burst can take place days or years after a supernova explosion. Our model is based on the conversion of a pure hadronic star (neutron star) into a star made at least in part of deconfined quark matter. The conversion process can be delayed if the surface tension at the interface between hadronic and deconfined-quark-matter phases is taken into account. The nucleation time (i.e. the time to form a critical-size drop of quark matter) can be extremely long if the mass of the star is small. Via mass accretion the nucleation time can be dramaticaly reduced and the star is finally converted into the stable configuration. A huge amount of energy, of the order of 10$^{52}$--10$^{53}$ erg, is released during the conversion process and can produce a powerful Gamma Ray Burst. The delay between the supernova explosion generating the metastable neutron star and the new collapse can explain the delay proposed in GRB990705 and in GRB011211.
Full-text · Article · Oct 2002 · The Astrophysical Journal
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##### Article: Gamma-ray bursts: a Centauro's cry?
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ABSTRACT: A new candidate for the gamma-ray bursts central engine is proposed: if in some energetic cosmic event a macroscopic amount of bubbles of the disoriented chiral condensate can be formed, then their subsequent decays will produce a relativistic fireball without the baryon loading problem. The neutron star to strange star transition is considered as a candidate example of such cosmic event.
Preview · Article · Apr 2003 · Acta Physica Polonica Series B