Strange Quark Stars: Structural Properties and Possible Signatures for Their Existence

Abstract

We give a brief introduction tothe physics of strange quark matter, and explore the possibilitythis novel deconfined phase of matter might be absolutely stable.Strange quark stars represent one of the most intriguing consequencesof such a possibility. We study the structural properties of thishypothetical new class of stellar compact objects, both for non-rotatingand rapidly rotating configurations in general relativity. Next,using recent observational data for the X-ray burster 4U 1820-30,the newly discovered millisecond X-ray pulsar SAX J1808.4-3658, andfor the atoll source 4U 1728-34, we argue that the compact stars inthese X-ray sources are likely strange star candidates. Finally, westudy the conversion of a neutron star to a strange quark star. Weshow that the total amount of energy liberated in the conversionprocess is in the range (1 - 4) x10^53 erg, in agreement with theenergy required to power gamma-ray bursts at cosmological distances.