相关论文: Magnetar Hard X-Ray Emission from Axion-like Parti…
Coupling of axions or axion-like particles (ALPs) with photons may lead to photons escaping optically opaque regions by oscillating into ALPs. This phenomenon may be viewed as the Light Shining through Wall (LSW) scenario. While this LSW…
X-ray emission from many rotation-powered millisecond pulsars (MSPs) is observed to be of predominantly thermal nature. In PSR J0437--4715, the nearest MSP known, an additional faint power-law tail is observed above 2.5 keV, commonly…
Reactor neutrino experiments provide a rich environment for the study of axionlike particles (ALPs). Using the intense photon flux produced in the nuclear reactor core, these experiments have the potential to probe ALPs with masses below 10…
The existence of an axion-like particle (ALP) would induce anomalous scattering of light by light. This process can be probed at the Large Hadron Collider in central exclusive production of photon pairs in proton-proton collisions by…
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…
If axion-like particles (ALPs) exist, photons can convert to ALPs on passage through regions containing magnetic fields. The magnetised intracluster medium of large galaxy clusters provides a region that is highly efficient at ALP-photon…
The axion-like particle (ALP)-photon mixing in the magnetic field around $\gamma$-ray sources or along the line-of-sight could induce oscillation between photons and ALPs, which then causes irregularities in the $\gamma$-ray spectra. In…
Soft Gamma-ray Repeaters (SGRs) and Anomalous X-ray Pulsars (AXPs) are interpreted as young highly magnetized neutron stars (NSs). Their X-ray luminosity in quiescence, exceeding 10^{35} erg s^{-1} cannot be explained as due to cooling of a…
The X-ray afterglow that is observed following large flares on magnetars can be accurately fit by simple and quantitative theoretical models: The long term afterglow, lasting of order weeks, can be understood as thermal radiation of a…
The surprising discovery by MAGIC of an intense, rapidly varying emission in the energy range 70 - 400 GeV from the flat spectrum radio quasar PKS 1222+216 represents a challenge for all interpretative scenarios. Indeed, in order to avoid…
The surfaces of neutron stars are likely sources of strongly polarized soft X rays due to the presence of strong magnetic fields. Scattering transport in the surface layers is critical to the determination of the emergent anisotropy of…
High energy gamma-rays propagating in external magnetic fields may convert into axion-like particles (ALPs). In this case, the observed gamma-ray spectra are modified by the resulting energy-dependent conversion probability. In this study,…
Axion-like particles (ALP) are promising candidates to comprise all the dark matter in the universe. We investigate the ALP couplings to photons and electrons via astrophysical measurements through the search for very-high-energy gamma rays…
Axion-Like Particles (ALPs) are predicted by several Beyond the Standard Model theories, in particular, string theory. In the presence of an external magnetic field perpendicular to the direction of propagation, ALPs can couple to photons.…
Photons propagating in an external magnetic field may oscillate into axions or axion-like particles (ALPs). Such oscillations will lead to characteristic features in the energy spectrum of high-energy photons from astrophysical sources that…
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…
Magnetars are the most luminous compact objects in the stellar mass range observed in the Milky Way, with giant flares of hard X-ray power ~10^45 erg/sec being detected from three soft gamma repeaters in the Galactic neighborhood.…
Axionlike particles (ALPs) are a common prediction of theories beyond the Standard Model of particle physics that could explain the entirety of the cold dark matter. These particles could be detected through their mixing with photons in…
The hard X-ray emission from magnetars and other isolated neutron stars remains under-explored. An instrument with higher sensitivity to hard X-rays is critical to understanding the physics of neutron star magnetospheres and also the…
Recently it has been suggested that dark radiation in the form of axions produced during the decay of string theory moduli fields could be responsible for the soft x-ray excess in galaxy clusters. These soft X-ray photons come about due to…