ﻻ يوجد ملخص باللغة العربية
We present a statistical study of the glitch population and the behaviour of the glitch activity across the known population of neutron stars. An unbiased glitch database was put together based on systematic searches of radio timing data of 898 rotation-powered pulsars obtained with the Jodrell Bank and Parkes observatories. Glitches identified in similar searches of 5 magnetars were also included. The database contains 384 glitches found in the rotation of 141 of these neutron stars. We confirm that the glitch size distribution is at least bimodal, with one sharp peak at approximately $20, rm{mu,Hz}$, which we call large glitches, and a broader distribution of smaller glitches. We also explored how the glitch activity $dot{ u}_{rm{g}}$, defined as the mean frequency increment per unit of time due to glitches, correlates with the spin frequency $ u$, spin-down rate $|dot{ u}|$, and various combinations of these, such as energy loss rate, magnetic field, and spin-down age. It is found that the activity is insensitive to the magnetic field and that it correlates strongly with the energy loss rate, though magnetars deviate from the trend defined by the rotation-powered pulsars. However, we find that a constant ratio $dot u_{rm{g}}/|dot u| = 0.010 pm 0.001$ is consistent with the behaviour of all rotation-powered pulsars and magnetars. This relation is dominated by large glitches, which occur at a rate directly proportional to $|dot{ u}|$. The only exception are the rotation-powered pulsars with the highest values of $|dot{ u}|$, such as the Crab pulsar and PSR B0540$-$69, which exhibit a much smaller glitch activity, intrinsically different from each other and from the rest of the population. The activity due to small glitches also shows an increasing trend with $|dot u|$, but this relation is biased by selection effects.
The sudden spin-down in the rotation of magnetar 1E 2259+586 observed by Archibald et al. (2013) was a rare event. However this particular event, referred to as an anti-glitch, was followed by another event which Archibald et al. (2013) suggested cou
We present in this article an overview of the problem of neutron star masses. After a brief appraisal of the methods employed to determine the masses of neutron stars in binary systems, the existing sample of measured masses is presented, with a high
We report on the timing and spectral properties of the soft X-ray emission from the magnetar 1E 2259+586 from January 2013, $sim 8$ months after the detection of an anti-glitch, until September 2019, using the Neil Gehrels Swift and NICER observatori
We present an analysis of regular timing observations of the high-magnetic-field Rotating Radio Transient (RRAT) J1819$-$1458 obtained using the 64-m Parkes and 76-m Lovell radio telescopes over the past five years. During this time, the RRAT has suf
The oscillation of neutrons $n$ into mirror neutrons $n$, their mass degenerate partners from dark mirror sector, can have interesting implications for neutron stars: an ordinary neutron star could gradually transform into a mixed star consisting in