The magnetospheric activity of bare strange quark stars

Understand

In Ruderman & Sutherland (RS75) model, the normal neutron stars as pulsars bear a severe problem, namely the binding energy problem that both ions (e.g., ${}_{26}^{56}$Fe) and electrons on normal neutron star surface can be pulled out freely by the unipolar generator induced electric field so that sparking on polar cap can hardly occur.

• {\bf This problem could be solved within the Partially Screened Gap (PSG) model in the regime of neutron stars}.
• However, in this paper we extensively study this problem in a bare strange quark star (BSS) model.
• We find that the huge potential barrier built by the electric field in the vacuum gap above polar cap could usually prevent electrons from streaming into the magnetosphere unless the electric potential of a pulsar is sufficiently lower than that at infinite interstellar medium.