||Thermal and Non-Thermal Radiation from Pulsars: Hints of Physics
||466, Electromagnetic Radiation from Pulsars and Magnetars
||Dai, S.; Xu, R.
||Thermal and non-thermal radiation from pulsars carries significant
information from surface and would have profound implications on the
state of dense matter in compact stars. For the non-thermal radio
emission, subpulse drifting phenomena suggest the existence of
Ruderman-Sutherland-like gap-sparking and strong binding of
particles on pulsar polar caps. While conventional neutron star
models can hardly provide such a high binding energy, the strong
self-bound surface of quark-cluster stars can naturally solve this
problem. As for the thermal one, the featureless X-ray spectra of
pulsars may indicate a bare surface without atmosphere, and the
ultrarelativistic fireball of γ-ray bursts and supernovae
would also require strong self-bound surfaces.
Recent achievements in measuring pulsar mass and mass-radius
relation further indicate a stiff equation of state and a
Therefore, we conjecture that matters inside pulsar-like compact
stars could be in a quark-cluster phase. The surface of quark-cluster
stars is chromatically confined and could initially be bare. Such a
surface can not only explain above features, but may also promote a
successful core-collapse supernova, and the hydro-cyclotron oscillation
of the electron sea above the surface could be responsible for those
absorption features detected in the X-ray spectrum.