scholarly journals Pulsar glitches in a strangeon star model. II. The activity

2020 ◽  
Vol 500 (4) ◽  
pp. 5336-5349
Author(s):  
W H Wang ◽  
X Y Lai ◽  
E P Zhou ◽  
J G Lu ◽  
X P Zheng ◽  
...  

ABSTRACT Glitch is supposed to be a useful probe into pulsar’s interior, but the underlying physics remains puzzling. The glitch activity may reflect a lower limit of the crustal moment of inertia in conventional neutron star models. Nevertheless, its statistical feature could also be reproduced in the strangeon star model, which is focused here. We formulate the glitch activity of normal radio pulsars under the framework of starquake of solid strangeon star model, the shear modulus of strangeon matter is constrained to be $\mu \simeq 3\times 10^{34}~\rm erg\,cm^{-3}$, consistent with previous work. Nevertheless, about ten times the shift in oblateness accumulated during glitch interval is needed to fulfill the statistical observations. The fact that typical glitch sizes of two rapidly evolving pulsars (the Crab pulsar and PSR B0540-69) are about two orders of magnitude lower than that of the Vela pulsar, significantly lower than the oblateness change they can supply, indicates probably that only a part of oblateness change is relieved when a pulsar is young. The unreleased oblateness and stress may relax as compensation in the following evolution. The small glitch sizes and low glitch activity of the Crab pulsar can be explained simultaneously in this phenomenological model. Finally, we obtain energy release to be $\Delta E\sim 2.4\times 10^{40}~\rm erg$ and $\Delta E\sim 4.2\times 10^{41}~\rm erg$ for typical glitch size of Δν/ν ∼ 10−6 (Vela-like) and ∼10−8 (Crab-like). The upcoming SKA may test this model through the energy release and the power-law relation between the reduced recovery coefficient $Q/|\dot{\nu }|^{1/2}$ and Δν/ν.

1974 ◽  
Vol 53 ◽  
pp. 189-207 ◽  
Author(s):  
David Pines ◽  
Jacob Shaham ◽  
Malvin A. Ruderman

We examine what inferences can be made regarding neutron star structure from observations of micro- and macroglitch behavior. After considering various theories it seems plausible that crustquakes offer an explanation for the Crab microglitches, while corequakes can explain the Vela macroglitches. It is concluded that the Crab pulsar has a mass of less than 0.5 M⊙ and is ∼ 90% superfluid neutrons while the Vela pulsar may possess a solid neutron core and have a mass of ∼ 0.7 M⊙ with a superfluid neutron abundance of ∼ 15%.


2000 ◽  
Vol 177 ◽  
pp. 485-490
Author(s):  
Victoria M. Kaspi

AbstractThe evidence for associations between neutron stars and supernova remnants is reviewed. After summarizing the situation for young radio pulsars, I consider the evidence from associations that young neutron stars can have properties very different from those of radio pulsars. This, though still controversial, shakes our simple perception of the Crab pulsar as prototypical of the young neutron star population.


2000 ◽  
Vol 177 ◽  
pp. 699-702 ◽  
Author(s):  
E. V. Gotthelf ◽  
G. Vasisht

AbstractWe propose a simple explanation for the apparent dearth of radio pulsars associated with young supernova remnants (SNRs). Recent X-ray observations of young remnants have revealed slowly rotating (P∼ 10s) central pulsars with pulsed emission above 2 keV, lacking in detectable radio emission. Some of these objects apparently have enormous magnetic fields, evolving in a manner distinct from the Crab pulsar. We argue that these X-ray pulsars can account for a substantial fraction of the long sought after neutron stars in SNRs and that Crab-like pulsars are perhaps the rarer, but more highly visible example of these stellar embers. Magnetic field decay likely accounts for their high X-ray luminosity, which cannot be explained as rotational energy loss, as for the Crab-like pulsars. We suggest that the natal magnetic field strength of these objects control their subsequent evolution. There are currently almost a dozen slow X-ray pulsars associated with young SNRs. Remarkably, these objects, taken together, represent at least half of the confirmed pulsars in supernova remnants. This being the case, these pulsars must be the progenitors of a vast population of previously unrecognized neutron stars.


2013 ◽  
Vol 44 (11) ◽  
pp. 2389
Author(s):  
M. Pieńkos

2009 ◽  
Author(s):  
Valery Suleimanov ◽  
Thomas Rauch ◽  
Klaus Werner ◽  
Alexander Y. Potekhin ◽  
Juri Poutanen ◽  
...  
Keyword(s):  

2002 ◽  
Vol 381 (1) ◽  
pp. 178-196 ◽  
Author(s):  
R. Prix ◽  
G. L. Comer ◽  
N. Andersson
Keyword(s):  

1987 ◽  
Vol 125 ◽  
pp. 67-78
Author(s):  
Ramesh Narayan

The radio pulsars in the Galaxy are found predominantly in the disk, with a scale height of several hundred parsecs. After allowing for pulsar velocities, the data are consistent with the hypothesis that single pulsars form from massive stellar progenitors. The number of active single pulsars in the Galaxy is ∼ 1.5 × 105, and their birthrate is 1 per ∼ 60 yrs. There is some evidence that many single pulsars, particularly those with high magnetic fields, are born spinning slowly, with initial periods ∼ 0.5–1s. This could imply an origin through binary “recycling” followed by orbit disruption, or might suggest that the pre-supernova stellar core efficiently loses angular momentum to the envelope through magnetic coupling. The birthrate of binary radio pulsars, particularly of the millisecond variety, seems to be much larger than previous estimates, and might suggest that these systems do not originate in low mass X-ray binary systems.


1971 ◽  
Vol 46 ◽  
pp. 341-345
Author(s):  
G. Chanmugam ◽  
M. Gabriel

The Nemeth-Sprung equation of state is modified and used to obtain neutron star models. Contrary to the results of some authors it is found that neutron stars with central densities ≲ 1014 g cm-3 are dynamically stable. It is suggested that some pulsars may belong to this category of stars.


2005 ◽  
Vol 14 (06) ◽  
pp. 1075-1082 ◽  
Author(s):  
AŞKIN ANKAY ◽  
SERKAN ŞAHIN ◽  
GÖKÇE KARANFIL ◽  
EFE YAZGAN

Two Galactic isolated strong X-ray pulsars seem to be in the densest environments compared to other types of Galactic pulsar. X-ray pulsar J1846-0258 can be in an early phase of anomalous X-ray pulsars and soft gamma repeaters if its average braking index is ~1.8–2.0. X-ray pulsar J1811-1925 must have a very large average braking index (~11) if this pulsar was formed by SN 386AD. This X-ray pulsar can be in an early phase of the evolution of the radio pulsars located in the region P ~ 50–150 ms and Ṗ ~ 10-14–10-16 ss -1 of the P–Ṗ diagram. X-ray/radio pulsar J0540-69 seems to be evolving in the direction to the dim isolated thermal neutron star region on the P–Ṗ diagram. Possible progenitors of different types of neutron star are also discussed.


1978 ◽  
Vol 224 ◽  
pp. 993 ◽  
Author(s):  
P. G. Whitman ◽  
R. W. Redding

Sign in / Sign up

Export Citation Format

Share Document