PSR B1828–11: a precession pulsar torqued by a quark planet?

Abstract

The pulsar PSR B1828-11 has long-term, highly periodic and correlated variations in both pulse shape and the rate of slow-down. This phenomenon may provide evidence for precession of the pulsar as suggested previously within the framework of free precession as well as forced one. On a presumption of forced precession, we propose a quark planet model to this precession henomenon instead, in which the pulsar is torqued by a quark planet. We construct this model by constraining mass of the pulsar ($M_{\rm psr}$), mass of the planet ($M_{\rm pl}$) and orbital radius of the planet ($r_{\rm pl}$). Five aspects are considered: derived relation between $M_{\rm psr}$ and $r_{\rm pl}$, movement of the pulsar around the center of mass, ratio of $M_{\rm psr}$ and $M_{\rm pl}$, gravitational wave radiation timescale of the planetary system, and death-line criterion. We also calculate the range of precession period derivative and gravitational wave strength (at earth) permitted by the model. Under reasonable parameters, the observed phenomenon can be understood by a pulsar ($10^{-4}\sim10^{-1}M_{\odot}$) with a quark planet ($10^{-8}\sim10^{-3}M_{\odot}$) orbiting it. According to the calculations presented, the pulsar would be a quark star because of its low mass, which might eject a lump of quark matter (to become a planet around) during its birth.Comment: 6 pages, 3 figures, accepted by MNRAS (Letters

Periodicity in fast radio bursts due to forced precession by a fallback disk

“…A similar expression is also obtained when considering forced precession for PSR B1828−11 by a planet (Liu et al 2007).…”

Emission-rotation correlation in pulsars: new discoveries with optimal techniques

“…Long-term variability in both the pulse profile shape and spindown rate are well established in PSR J1830−1059, along with correlation between the two (Lyne et al 2010). The variability has been attributed to free precession (Stairs et al 2000;Jones 2012) or the effects of an orbiting quark planet (Liu et al 2007). Quasi-periodic profile changes can be seen clearly in Panels A and B of Figure 8.…”

Searching for substellar companions of young isolated neutron stars

“…In the context of our work, it is interesting to note, why forced precession, e.g., by a substellar companion, is impossible. For example, Liu et al (2007) discussed forced precession by a planet for PSR B1828-11. In the case of RX J0720.4-3125, we can apply the same formula as Liu et al (2007) to approximate the orbital radius needed for planets lighter than 15 Jupiter masses to cause the precession observed.…”

“…For example, Liu et al (2007) discussed forced precession by a planet for PSR B1828-11. In the case of RX J0720.4-3125, we can apply the same formula as Liu et al (2007) to approximate the orbital radius needed for planets lighter than 15 Jupiter masses to cause the precession observed. The largest orbital radius these planets could have, would be 1 × 10 −5 AU (for zero inclination, NS distortion of 4 × 10 −8 ).…”