Related papers: A deep ensemble approach to X-ray polarimetry

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…

We review the tools and procedures for the analysis of the data collected by X-ray photoelectric gas polarimeters, like the ones on-board the Imaging X-ray Polarimetry Explorer (IXPE). Although many of such tools are in principle common…

Particle acceleration mechanisms in supermassive black hole jets, such as shock acceleration, magnetic reconnection, and turbulence, are expected to have observable signatures in the multi-wavelength polarization properties of blazars. The…

Weakly magnetized neutron stars (WMNS) are complicated sources with challenging phenomenology. For decades, they have been studied via spectrometry and timing. It has been established that the spectrum of WMNSs consists of several…

This paper presents a data processing algorithm with machine learning for polarization extraction and event selection applied to photoelectron track images taken with X-ray polarimeters. The method uses a convolutional neural network (CNN)…

We report the discovery of significant X-ray polarization from the dynamically confirmed black hole X-ray binary (BHXB) GS 1354-64 during its 2025-2026 outburst, obtained with the Imaging X-ray Polarimetry Explorer (IXPE). The observation,…

X-ray binaries hosting a compact object have been among the main targets of the Imaging X-ray Polarimetry Explorer (IXPE) since its launch, due to their high brightness in the 2-8 keV energy band. The spectropolarimetric analysis performed…

Polarimetry is an area of high energy astrophysics which is still relatively unexplored, even though it is recognized that this type of measurement could drastically increase our knowledge of the physics and geometry of high energy sources.…

In this paper, we introduce Deep Probabilistic Ensembles (DPEs), a scalable technique that uses a regularized ensemble to approximate a deep Bayesian Neural Network (BNN). We do so by incorporating a KL divergence penalty term into the…

The Gas Pixel Detector (GPD) is a new generation device which, thanks to its 50 um pixels, is capable of imaging the photoelectrons tracks produced by photoelectric absorption in a gas. Since the direction of emission of the photoelectrons…

In astronomy there are basically four kinds of observations to extract the information carried by electromagnetic radiation: photometry, imaging, spectroscopy and polarimetry. By optimal exploitation of the first three techniques, X-ray…

This work introduces a novel probabilistic deep learning technique called deep Gaussian mixture ensembles (DGMEs), which enables accurate quantification of both epistemic and aleatoric uncertainty. By assuming the data generating process…

Radiation from X-ray pulsars (XRPs) was expected to be strongly linearly polarized owing to a large difference in their ordinary and extraordinary mode opacities. The launch of IXPE allowed us to check this prediction. IXPE observed a dozen…

In this paper, we propose a novel Explanation Neural Network (XNN) to explain the predictions made by a deep network. The XNN works by learning a nonlinear embedding of a high-dimensional activation vector of a deep network layer into a…

Reconstructing the structure of thin films and multilayers from measurements of scattered X-rays or neutrons is key to progress in physics, chemistry, and biology. However, finding all structures compatible with reflectometry data is…

This dissertation elaborates on X-ray polarisation features of astrophysical environments near accreting black holes. Although the work was originally assigned to supermassive black holes in active galactic nuclei, the results are also…

Magnetic turbulence plays a crucial role in confining charged particles near the shock front of Supernova Remnants, enabling them to reach energies up to hundreds of TeV through a process known as Diffusive Shock Acceleration (DSA). These…

X-ray binary systems consist of a companion star and a compact object in close orbit. Thanks to their copious X-ray emission, these objects have been studied in detail using X-ray spectroscopy and timing. The inclination of these systems is…

X-ray polarimetry is still largely uncharted territory. With the upcoming launch of IXPE, we will learn a lot more about X-ray polarization at energies above 2 keV, but so far no current or accepted mission provides observational…

X-ray polarimetric observations from the Imaging X-ray Polarimeter Explorer (IXPE) is an excellent tool for probing the geometry and dynamics of X-ray emitting corona in active galactic nuclei (AGN). This work aims to investigate the…