Two types of glitches in a solid quark star model

TL;DR

This paper proposes a starquake model for solid quark stars, identifying two glitch types—Type I with no energy release and Type II with significant energy release—explaining different observational glitch phenomena.

Contribution

It introduces a two-type glitch model in solid quark stars, linking glitch types to energy release and stellar processes, advancing understanding of pulsar glitch mechanisms.

Findings

Type I glitches involve no significant energy release.

Type II glitches involve notable energy release and are possibly caused by accretion.

Different glitch types explain diverse pulsar observational phenomena.

Abstract

Glitch (sudden spinup) is a common phenomenon in pulsar observations. However, the physical mechanism of glitch is still a matter of debate because it depends on the puzzle of pulsar's inner structure, i.e., the equation of state of dense matter. Some pulsars (e.g., Vela-like) show large glitches ({\Delta}{\nu}/{\nu}~10^-6) but release negligible energy, whereas the large glitches of AXPs/SGRs (anomalous X-ray pulsars/soft gamma repeaters) are usually (but not always) accompanied with detectable energy releases manifesting as X-ray bursts or outbursts. We try to understand this aspect of glitches in a starquake model of solid quark stars. There are actually two kinds of glitches in this scenario: bulk-invariable (Type I) and bulk-variable (Type II) ones. The total stellar volume changes (and then energy releases) significantly for the latter but not for the former. Therefore, glitches accompanied with X-ray bursts (e.g., that of AXP/SGRs) could originate from Type II starquakes induced probably by accretion, while the others without evident energy release (e.g., that of Vela pulsar) would be the result of Type I starquakes due to, simply, a change of stellar ellipticity.