相关论文: "Anti-glitches" in the Quark-Nova model for AXPs
The detection of optical/infrared counterparts to Anomalous X-ray Pulsars (AXPs) has greatly increased our understanding of these systems. Models for the AXP phenomenon were based upon their X-ray emission, and all but the magnetar model…
I review recent observational progress on Anomalous X-ray Pulsars, with an emphasis on timing, variability, and spectra. Highlighted results include the recent timing and flux stabilization of the notoriously unstable AXP 1E 1048.1-5937,…
Recently reported observations of magnetar glitches and coincident X-ray long term brightening events establish enough of a data base to indicate that the brightening events are accompanied by glitches at their outset, and that they are…
Anomalous X-ray Pulsars (AXPs) are a class of rare X-ray pulsars whose energy source has been perplexing for some 20 years. Unlike other, better understood X-ray pulsars, AXPs cannot be powered by rotation or by accretion from a binary…
Transient radio emission from X-ray binaries is associated with synchrotron emission from collimated jets that escape the system, and accreting millisecond X-ray pulsars (AMXPs) are no exception. Although jets from black hole X-ray binaries…
The origin of the recently discovered new class of transients, X-ray quasi-periodic eruptions (QPEs), remains a puzzle. Due to their periodicity and association with active galactic nuclei (AGN), it is natural to relate these eruptions to…
A neutron star in binary orbit with a low-mass non-degenerate companion becomes a source of x-rays with millisecond variability when mass accretion spins it up. Centrifugally driven changes in density profile may initiate a phase transition…
In a previous paper (Ouyed et al. 2004) we presented a new model for soft gamma-ray repeaters (SGR), based on the onset of colour superconductivity in quark stars. In this model, the bursts result from the reorganization of the exterior…
When a spinning-down neutron star undergoes a phase transition that produces quark matter in its core, a Super-Giant Glitch of the order ${\Delta} \Omega/\Omega\sim 0.3$ occurs on time scales from 0.05 seconds to a few minutes. The energy…
Assuming that AXPs and SGRs accrete matter from a fallback disk, we attempt to explain both the soft and the hard X-ray emission as the result of the accretion process. We also attempt to explain their radio emission or the lack of it. We…
The neutron star crust is rigid material floating on a neutron-proton liquid core. As the star's spin rate slows, the changing stellar shape stresses the crust and causes fractures. These starquakes may trigger pulsar glitches as well as…
A number of Anomalous X-ray Pulsars (AXPs) have recently been detected in the optical/IR wavelengths. We use their inferred brightness to place general constraints on any model for this emission within the magnetar framework. We find that…
We show that the Keplerian thin disk in quiescent Soft X-ray Transients cannot extend down to the last stable orbit around the central black hole. We analyse the properties of the Narayan, McClintock & Yi (1996) model of quiescent Soft…
We present evidence for three spin-down glitches (or `anti-glitches') in the ultraluminous accreting X-ray pulsar NGC 300 ULX-1 in timing observations made with the Neutron Star Interior Composition Explorer (NICER). Our timing analysis…
Accretion discs around black holes power some of the most luminous objects in the Universe. Discs that are misaligned to the black hole spin can become warped over time by Lense-Thirring precession. Recent work has shown that strongly…
Recent measurements of the spin-down rates of soft gamma ray repeaters (SGRs) and anomalous X-ray pulsars (AXPs) have been interpreted as evidence that these objects are ``magnetars'': neutron stars spinning down by magnetic dipole…
After at least 6 years of quiescence, Anomalous X-ray Pulsar (AXP) 4U 0142+61 entered an active phase in 2006 March that lasted several months and included six X-ray bursts as well as many changes in the persistent X-ray emission. The…
We show that old isolated neutron stars in groups and clusters of galaxies experiencing a Quark-Nova phase (QN: an explosive transition to a quark star) may be the source of FRBs. Each of the millions of fragments of the ultra-relativistic…
The magnetar model and a solid quark star model for anomalous X-ray pulsars/soft gamma-ray repeaters (AXPs/SGRs) are discussed. Different manifestations of pulsar-like stars are speculated to be due to both their nature (e.g., mass and…
We show that sudden variations in the composition and structure of an hybrid star can be triggered by its rapid spin-down, induced by r-mode instabilities. The discontinuity of this process is due to the surface tension between hadronic and…