Related papers: "Anti-glitches" in the Quark-Nova model for AXPs
The recently observed antiglitch of AXP 1E 2259+586 is inconsistent with magnetar models, but may be explained as the consequence of sudden accretion of retrograde matter or "propeller" interaction with surrounding matter. AXP/SGR are…
(Abridged) XTE J1810-197 and 1E 1547.0-5408 are two transient AXPs exhibiting radio emission with unusual properties. In addition, their spin down rates during outburst show opposite trends, which so far has no explanation. Here, we extend…
Quark-novae leave behind quark stars with a surrounding metal-rich fall-back (ring-like) material. These compact remnants have high magnetic fields and are misconstrued as magnetars; however, several observational features allow us to…
Magnetars are fascinating objects that are thought to be neutron stars powered by their strong internal magnetic fields. Clear evidence of a sudden spin-down was detected in the Anomalous X-ray Pulsar AXP 1E 2259+586, an object cataloged as…
We explore the formation and evolution of debris ejected around quark stars in the Quark Nova scenario, and the application to Soft Gamma-ray Repeaters (SGRs) and Anomolous X-ray Pulsars (AXPs). If an isolated neutron star explodes as a…
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…
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…
Three sudden spin-down events, termed `anti-glitches', were recently discovered in the accreting pulsar NGC 300 ULX-1 by the \textit{Neutron Star Interior Composition Explorer} (NICER) mission. Unlike previous anti-glitches detected in…
We examined the fall-back disk models, and in general accretion, proposed to explain the properties of anomalous X-ray pulsars (AXPs), soft gamma repeaters (SGRs), and radio pulsars (PSRs). We checked the possibility of some gas remaining…
We consider the accretion model for anomalous X-ray pulsars proposed recently by Chatterjee, Hernquist and Narayan, in which the emission is powered by accretion from a fossil disk formed by the fallback of material from a supernova…
TThe glitch of anomalous X-ray pulsars \& soft gamma repeaters (AXP/SGRs) usually accompanied with detectable energy releases manifesting as X-ray bursts or outbursts, while the glitch of some pulsars like Vela release negligible energy. We…
The Anomalous X-ray Pulsar (AXP) 1E 1547.0-5408 reactivated in 2009 January with the emission of dozens of short bursts. Follow-up observations with Swift/XRT and XMM-Newton showed the presence of multiple expanding rings around the…
Some accreting neutron stars and young stars show unexplained episodic flares in the form of quasi-periodic oscillations or recurrent outbursts. In a series of two papers we present new work on an instability that can lead to episodic…
During 2003 and 2004 the Anomalous X-Ray Pulsar XTE J1810-197 went through a series of four bursts. The spectrum in the tail of one of these bursts shows a strong, significant emission feature ~13 keV, thereby encoding a wealth of…
We attribute the rapid spindown of magnetar 1E 2259+586 observed by Archibald et al. (2013), termed the "anti-glitch", to partial opening of the magnetosphere during the X-ray burst, followed by changes of the structure of the closed field…
We present a model for the anomalous X-ray pulsars (AXPs) in which the emission is powered by accretion from a fossil disk, established from matter falling back onto the neutron star following its birth. The time-dependent accretion drives…
Magnetars are neutron stars showing dramatic X-ray and soft $\gamma$-ray outbursting behaviour that is thought to be powered by intense internal magnetic fields. Like conventional young neutron stars in the form of radio pulsars, magnetars…
P-stars are compact stars made of up and down quarks in $\beta$-equilibrium with electrons in a chromomagnetic condensate. We discuss p-stars endowed with super strong dipolar magnetic field which, following consolidated tradition in…
We explore a possibility to explain the phenomenon of the Anomalous X-ray Pulsars (AXP) and Soft Gamma-ray Repeaters (SGR) within the scenario of fall-back magnetic accretion onto a young isolated neutron star. The X-ray emission of the…
The origin and stability of a thin sheet of plasma in the magnetosphere of an accreting neutron star is investigated. First the radial extension of such a magnetospheric disc is explored. Then a mechanism for magnetospheric accretion is…