Related papers: Unbinned Likelihood Analysis for X-ray Polarizatio…
Unfolding, in the context of high-energy particle physics, refers to the process of removing detector distortions in experimental data. The resulting unfolded measurements are straightforward to use for direct comparisons between…
We analyze atomic photoexcitation into the discrete states by twisted photons, or photons carrying extra orbital angular momentum along their direction of propagation. From the angular momentum and parity considerations, we are able to…
Filled arrays of bolometers are currently being employed for use in astronomy from the far-infrared through millimeter parts of the electromagnetic spectrum. Because of the large range of wavelengths for which such detectors are applicable,…
Low-Luminosity Active Galactic Nuclei (LLAGN) provides a unique view of Comptonization and non-thermal emission from accreting black holes in the low-accretion rate regime. However, to decipher the exact nature of the Comptonizing corona in…
We study the polarization characteristics of x-ray photons scattered by hydrogenic atoms, based on the Dirac equation and second-order perturbation theory. The relativistic states used in calculations are obtained using the finite basis set…
In this paper we propose a way to use optical polarisation observations to provide independent constraints and guide to the modelling of the spectral energy distribution (SED) of blazars, which is particularly useful when two-zone models…
Light has many properties that vision sensors can passively measure. Colour-band separated wavelength and intensity are arguably the most commonly used for monocular 6D object pose estimation. This paper explores how complementary…
X-ray polarimetry will soon open a new window on the high energy universe with the launch of NASA's Imaging X-ray Polarimetry Explorer (IXPE). Polarimeters are currently limited by their track reconstruction algorithms, which typically use…
Context. In September 2022, the transient neutron star low-mass X-ray binary XTE J1701-462 went into a new outburst. Aims. The objective of this work is to examine the evolution of the accretion geometry of XTE J1701-462 by studying the…
We report on the coordinated observations of the neutron star low-mass X-ray binary (NS-LMXB) \gx in X-rays (IXPE, NICER, Nustar and INTEGRAL), optical (REM and LCO), near-infrared (REM), mid-infrared (VLT VISIR), and radio (ATCA). This…
An angle-resolved x-ray spectroscopic scheme is presented for determining the hyperfine splitting of highly charged ions. For helium-like ions, in particular, we propose to measure either the angular distribution or polarization of the…
This study presents an X-ray spectropolarimetric characterisation of the Z-source GX 340+0 during the normal branch (NB) and compares it with that obtained for the horizontal branch (HB), using IXPE, NICER and NuSTAR observations. The…
The X-ray polarization of Sco X-1 was measured for the first time with very high significance by the Imaging X-ray Polarimeter Explorer (IXPE). A polarization degree of 1.0% $\pm$ 0.2% at a PA of 8{\deg} $\pm$ 6{\deg} at 90% confidence…
The paper presents model pulse profiles from binary accreting X-ray pulsars using high-resolution numerical simulations for pencil and fan emission beam geometries, each with two different optical depths obtained using a new numerical code…
Quantum measurements that use the entangled photons' polarization to encode quantum information require calibration and alignment of the measurement bases between spatially separate observers. Because of the changing birefringence in…
The X-ray binary pulsar Her X-1 shows a wide variety of long and short term variabilities in the X-ray light curve. The 35 d variability of the source is interpreted as the influence of a warped, inclined, and twisted accretion disk…
We present detailed instructions for constructing and operating an apparatus to produce and detect polarization-entangled photons. The source operates by type-I spontaneous parametric downconversion in a two-crystal geometry. Photons are…
The Imaging X-ray Polarimetry Explorer (IXPE) observations of the X-ray binary 4U 1630-47 in the high soft state revealed high linear polarization degrees (PDs) rising from 6% at 2 keV to 10% at 8 keV. We discuss in this letter three…
We introduce a method for extracting spectral information from energy-resolved light curves folded at the neutron star spin period (known as pulse profiles) in accreting X-ray binaries. Spectra of these sources are sometimes characterized…
New X-ray polarisation results are challenging our understanding of the accretion flow geometry in black hole binary systems. Even spectra dominated by a standard disc can give unexpected results, such as the high inclination black hole…