Astron. Astrophys. 364, L89-L92 (2000)

1. Introduction

A calculation for cold strange stars (D98) enabled us to draw conclusions about chiral symmetry restoration in QCD when the EOS was used to get SS fitting definite mass-radius (MR) relations (D98; Li et al. 1999a; Li et al. 1999b; Ray et al. 2000b). The empirical MR relations were derived from astrophysical observations like luminosity variation and some properties of quasi-periodic oscillations from compact stars. The calculations are compared to these stars which emit X-rays, generated presumably due to accretion from their binary partner.

During the genesis of these stars higher T may be encountered and in this paper we deal with a generalized case of an object at a uniform T. We show at upto T = 70 MeV a self sustained system can be supported by the parameter set eos1 (D98) (called SS1 in Li et al. 1999a).

The changes in star masses are shown in the range of T mentioned above. The conclusions of D98 and Li et al. (1999a, 1999b) are still valid for the finite T cases. Secondly, parameters of the single particle potential at finite T are tabulated. In particular the entropy is studied and this can be compared with hadronic models. The comparison shows that the entropy may indeed be continuous supporting the idea of a continuous phase transition between hadrons and quarks.

© European Southern Observatory (ESO) 2000

Online publication: January 29, 2001
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