nIs RX
J1856.5-3754 the first quark/strange star discovered ?
(Drake et al, 2002; Xu, 2002)
Þ Bare quark stars not covered by an
atmosphere would presumably emit a pure blackbody spectrum
Þ (2th component for the optical emission)
n Other options : NS models based on a two-T surface distribution
(Pons et al, 2002; Walter &
Lattimer, 2002 )
Þ May account for X-ray to optical
emission
Þ Give acceptable values for the star
radius
But how to produce a featureless spectrum from a NS covered with an
optically thick atmosphere ??
How the spectrum of a quark star looks like ??