射电天文研究室知识库

In this paper, we modify our previous research carefully, and derive a new expression of electron energy density in superhigh magnetic fields. Based on our improved model, we re-compute the electron capture rates and the magnetic fields' evolutionary timescales t of magnetars. According to the calculated results, the superhigh magnetic fields may evolve on timescales similar to(10(6)-10(7)) yrs for common magnetars, and the maximum timescale of the field decay, ta parts per thousand 2.9507x10(6) yrs, corresponding to an initial internal magnetic field B (0)=3.0x10(15) G and an initial inner temperature T (0)=2.6x10(8) K. Motivated by the results of the neutron star-supernova remnant (SNR) association of Zhang and Xie (2011), we calculate the maximum B (0) of magnetar progenitors, B (max)similar to(2.0x10(14)-2.93x10(15)) G when T (0)=2.6x10(8) K. When T (0)similar to 2.75x10(8)-1.75x10(8) K, the maximum B (0) will also be in the range of similar to 10(14)-10(15) G, not exceeding the upper limit of magnetic field of a magnetar under our magnetar model. We also investigate the relationship between the spin-down ages of magnetars and the ages of their SNRs, and explain why all AXPs associated with SNRs look older than their real ages, whereas all SGRs associated with SNRs appear younger than they are.