相关论文: X-ray spectra and polarization from magnetar candi…
Over the next year, a new era of observations of compact objects in X-ray polarization will commence. Among the key targets for the upcoming Imaging X-ray Polarimetry Explorer mission, will be the magnetars 4U 0142+61 and 1RXS…
The study of magnetars is of particular relevance since these objects are the only laboratories where the physics in ultra-strong magnetic fields can be directly tested. Until now, spectroscopic and timing measurements at X-ray energies in…
Emission spectra from magnetars in the soft X-ray band likely contain a thermal component emerging directly from the neutron star surface. However, the lack of observed absorption-like features in quiescent spectra makes it difficult to…
In the magnetar model, the quiescent non-thermal soft X-ray emission from Anomalous X-ray Pulsars and Soft-Gamma Repeaters is thought to arise from resonant comptonization of thermal photons by charges moving in a twisted magnetosphere.…
The quantum electrodynamics (QED) theory predicts that the quantum vacuum becomes birefringent in the presence of ultra-strong magnetic fields -- a fundamental effect yet to be directly observed. Magnetars, isolated neutron stars with…
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.…
X-ray polarimetry promises to give qualitatively new information about high-energy sources. Examples of interesting source classes are binary black hole systems, rotation and accretion powered neutron stars, Microquasars, Active Galactic…
The launch of IXPE telescope in late 2021 finally made polarization measurements in the 2-8 keV band a reality, more than 40 years after the pioneering observations of the OSO-8 satellite. In the first two years of operations IXPE targeted…
Magnetars, the most strongly magnetised neutron stars, are among the most promising targets for X-ray polarimetry. The Imaging X-ray Polarimetry Explorer (IXPE), the first satellite devoted to exploring the sky in polarised X-rays, has…
X-ray polarimetry promises us an unprecedented look at the structure of magnetic fields and on the processes at the base of acceleration of particles up to ultrarelativistic energies in relativistic jets. Crucial pieces of information are…
Magnetars are neutron stars that host huge, complex magnetic fields which require supporting currents to flow along the closed field lines. This makes magnetar atmospheres different from those of passively cooling neutron stars because of…
The anomalous X-ray pulsars and soft gamma-repeaters are peculiar high-energy sources believed to host a magnetar, i.e. an ultra-magnetized neutron star. Their persistent, soft X-ray emission (~1-10 keV)is usually modeled by the…
In this paper, we discuss our first attempts to model the broadband persistent emission of magnetars within a self consistent, physical scenario. We present the predictions of a synthetic model that we calculated with a new Monte Carlo 3-D…
We review the polarization properties of X-ray emission from highly magnetized neutron stars, focusing on emission from the stellar surfaces. We discuss how x-ray polarization can be used to constrain neutron star magnetic field and…
Magnetars are the strongest magnets in the present universe and the combination of extreme magnetic field, gravity and density makes them unique laboratories to probe current physical theories (from quantum electrodynamics to general…
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…
We argue that measurements of X-ray polarization using the recently launched Imaging X-ray Polarimetry Explorer will answer many open questions about magnetars in particular the physical state of their surfaces, whether vacuum birefringence…
Radiative corrections of quantum electrodynamics cause a vacuum threaded by magnetic field to be birefringent. This means that radiation of different polarizations travels at different speeds. Even in the strong magnetic fields of…
Magnetars are a unique class of neutron stars characterized by their incredibly strong magnetic fields. Unlike normal pulsars whose X-ray emission was driven by rotational energy loss, magnetars exhibit distinct X-ray emissions thought to…
We examine the expected X-ray polarization properties of neutron-star X-ray sources of various types, e.g., accretion and rotation powered pulsars, magnetars, and low-mass X-ray binaries. We summarize the model calculations leading to these…