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This review paper outlines background information and covers recent advances made via the analysis of spectra and images of prominence plasma and the increased sophistication of non-LTE (ie when there is a departure from Local Thermodynamic…

Solar and Stellar Astrophysics · Physics 2011-05-10 N. Labrosse , P. Heinzel , J. -C. Vial , T. Kucera , S. Parenti , S. Gunar , B. Schmieder , G. Kilper

The structure of liquid N-methylformamide (NMF) has been investigated using synchrotron radiation at 77 and 95 keV. The use of high energy photons has several advantages, in this case especially the large accessible momentum transfer range,…

chem-ph · Physics 2015-06-24 J. Neuefeind , M. D. Zeidler , H. F. Poulsen

Comprehensive understanding of thermal transport in nanostructured materials needs large scale simulations bridging length scales dictated by different physics related to the wave versus particle nature of phonons. Yet, available…

Mesoscale and Nanoscale Physics · Physics 2020-04-10 Dhritiman Chakraborty , Hossein Karamitaheri , Laura de Sousa Oliveira , Neophytos Neophytou

Chain of calculations which have to be performed to predict any kind of signal in a deep underwater/ice neutrino detector necessarily includes the lepton propagation through thick layers of matter, as neutrino can be observed only by means…

High Energy Physics - Phenomenology · Physics 2007-05-23 I. A. Sokalski , E. V. Bugaev , S. I. Klimushin

We present a radiative transfer model, which is applicable to the study of submillimetre spectral line observations of protostellar envelopes. The model uses an exact, non-LTE, spherically symmetric radiative transfer `Stenholm' method,…

Astrophysics · Physics 2009-11-06 D. Ward-Thompson , H. D. Buckley

Most of the physical information about astrophysical objects is obtained via the analysis of their electromagnetic spectra. Observed data coupled with radiation transfer models in physical conditions representative of stars, planets,…

Solar and Stellar Astrophysics · Physics 2026-05-29 Maria Bergemann , Richard Hoppe

The shaping of planetary nebulae on their evolution from asymptotic giant branch circumstellar envelopes to their final, most often axisymmetrical, form is still a process with many unknown details. The key to understanding the whole…

High-fidelity simulated astronomical images are an important tool in developing and measuring the performance of image-processing algorithms, particularly for high precision measurements of cosmic shear -- correlated distortions of images…

Instrumentation and Methods for Astrophysics · Physics 2024-03-25 Claire-Alice Hébert , Joshua E. Meyers , My H. Do , Patricia R. Burchat , the LSST Dark Energy Science Collaboration

Despite the remarkable success of diffusion models (DMs) in data generation, they exhibit specific failure cases with unsatisfactory outputs. We focus on one such limitation: the ability of DMs to learn hidden rules between image features.…

Computer Vision and Pattern Recognition · Computer Science 2025-02-10 Yujin Han , Andi Han , Wei Huang , Chaochao Lu , Difan Zou

We present a new framework for radiation hydrodynamics simulations. Gas dynamics is modelled by the Smoothed Particle Hydrodynamics (SPH) method, whereas radiation transfer is simulated via a time-dependent Monte-Carlo approach that traces…

Instrumentation and Methods for Astrophysics · Physics 2015-05-13 Sergei Nayakshin , Seung-Hoon Cha , Alexander Hobbs

The widespread dissemination of machine learning tools in science, particularly in astronomy, has revealed the limitation of working with simple single-task scenarios in which any task in need of a predictive model is looked in isolation,…

High Energy Astrophysical Phenomena · Physics 2018-12-27 Ricardo Vilalta

We present a verification of a computational model, developed at the Los Alamos National Laboratory (LANL) for simulating radiation transfer in X-ray bursting neutron star atmospheres. We tested a baseline case and demonstrated strong…

High Energy Astrophysical Phenomena · Physics 2026-02-05 Lourenzo Colleyn , Zach Medin , Alan Calder

We study the transport of high-energy particles in pulsar wind nebulae (PWN) using three-dimensional MHD (see Porth et al. (2014) for details) and test-particle simulations, as well as a Fokker-Planck particle transport model. The latter…

High Energy Astrophysical Phenomena · Physics 2016-07-27 O. Porth , M. J. Vorster , M. Lyutikov , N. E. Engelbrecht

The modeling of the peculiar scattering polarization signals observed in some diagnostically important solar resonance lines requires the consideration of the detailed spectral structure of the incident radiation field as well as the…

Solar and Stellar Astrophysics · Physics 2015-12-02 Luca Belluzzi , Javier Trujillo Bueno , Egidio Landi Degl'Innocenti

Rendering highly scattering participating media using brute force path tracing is a challenge. The diffusion approximation reduces the problem to solving a simple linear partial differential equation. Flux-limited diffusion introduces…

Graphics · Computer Science 2018-07-03 David Koerner , Jamie Portsmouth , Wenzel Jakob

We develop a method of analyzing radio frequency spectral line observations to derive data on the temperature, density, velocity, and molecular abundance of the emitting gas. The method incorporates a radiative transfer code with a new…

Astrophysics · Physics 2009-11-10 Eric Keto , George B. Rybicki , Edwin A. Bergin , Rene Plume

We developed a three-dimensional radiative transfer code for an ultra-relativistic background flow-field by using the Monte Carlo (MC) method in the context of gamma-ray burst (GRB) emission. For obtaining reliable simulation results in the…

High Energy Astrophysical Phenomena · Physics 2017-09-13 Ayako Ishii , Naofumi Ohnishi , Hiroki Nagakura , Hirotaka Ito , Shoichi Yamada

We present a novel numerical implementation of radiative transfer in the cosmological smoothed particle hydrodynamics (SPH) simulation code {\small GADGET}. It is based on a fast, robust and photon-conserving integration scheme where the…

Astrophysics · Physics 2009-06-23 M. Petkova , V. Springel

This study investigate the effectiveness of using Deep Learning (DL) for the classification of planetary nebulae (PNe). It focusses on distinguishing PNe from other types of objects, as well as their morphological classification. We adopted…

Instrumentation and Methods for Astrophysics · Physics 2021-02-01 Dayang N. F. Awang Iskandar , Albert A. Zijlstra , Iain McDonald , Rosni Abdullah , Gary A. Fuller , Ahmad H. Fauzi , Johari Abdullah