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Related papers: Radiative transfer with opacity distribution funct…

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To measure the column densities of interstellar and intergalactic gas clouds using absorption line spectroscopy, the apparent optical depth technique (AOD) of Savage & Sembach (1991) can be used instead of a curve-of-growth analysis or…

Astrophysics · Physics 2008-11-26 Andrew J. Fox , Blair D. Savage , Bart P. Wakker

This thesis presents an original model for the FIR emission in spirals, developed from an existing radiative transfer code (Bianchi, Ferrara & Giovanardi, 1996, ApJ, 465, 127). The model's main features are: a complete treatment of multiple…

Astrophysics · Physics 2007-05-23 Simone Bianchi

High mobility environment leads to severe Doppler effects and poses serious challenges to the conventional physical layer based on the widely popular orthogonal frequency division multiplexing (OFDM). The recent emergence of orthogonal time…

Signal Processing · Electrical Eng. & Systems 2025-02-14 Qinwen Deng , Yao Ge , Zhi Ding

We have developed a public code, Optab, that outputs Rosseland, Planck, and two-temperature Planck mean gas opacity tables for radiation hydrodynamics simulations in astrophysics. The code is developed for modern high-performance computing,…

Instrumentation and Methods for Astrophysics · Physics 2022-03-14 Shigenobu Hirose , Peter Hauschildt , Takashi Minoshima , Kengo Tomida , Takayoshi Sano

We present the results of a series of calculations studying the collapse of molecular cloud cores performed using a three-dimensional smoothed particle hydr odynamics code with radiative transfer in the flux-limited diffusion approximation.…

Astrophysics · Physics 2009-11-13 Stuart C. Whitehouse , Matthew R. Bate

Radiative transfer is essential in astronomy, both for interpreting observations and simulating various astrophysical phenomena. However, self-consistent line radiative transfer is computationally expensive, especially in 3D. To reduce the…

Instrumentation and Methods for Astrophysics · Physics 2025-05-14 Thomas Ceulemans , Frederik De Ceuster , Leen Decin

The [CII] 158$\mu$m emission line can arise in all phases of the ISM, therefore being able to disentangle the different contributions is an important yet unresolved problem when undertaking galaxy-wide, integrated [CII] observations. We…

Astrophysics of Galaxies · Physics 2016-11-23 Gioacchino Accurso , Amélie Saintonge , Thomas. G. Bisbas , Serena Viti

Context. Three-dimensional non-local thermodynamical equilibrium (NLTE) radiative transfer calculations are a fundamental tool for a detailed spectral analysis in stellar atmospheres, but require vast amounts of computer power. This…

Solar and Stellar Astrophysics · Physics 2023-07-12 Elias R. Udnæs , Tiago M. D. Pereira

The atmospheres of massive O-type stars (O stars) are dynamic, turbulent environments resulting from radiatively driven instabilities over the iron bump, located slightly beneath the stellar surface. Here, complex radiation hydrodynamic…

Cosmic dust is present in many astrophysical objects, and recent observations across the electromagnetic spectrum show that the dust distribution is often strongly three-dimensional (3D). Dust grains are effective in absorbing and…

Instrumentation and Methods for Astrophysics · Physics 2015-06-15 Juergen Steinacker , Maarten Baes , Karl Gordon

We have developed a new model that uses a cellular approach to calculate radiative transfer of starlight through dusty media. The model is designed to be user friendly enough to be distributed as a tool for use by the general astronomical…

Astrophysics · Physics 2009-09-25 Matthew Trewhella , Barry F. Madore , Leslie Kuchinski

We discuss work toward developing a 2.5D non-LTE radiative transfer code. Our code uses the short characteristic method with modifications to handle realistic 3D wind velocities. We also designed this code for parallel computing facilities…

Astrophysics · Physics 2007-05-23 J. Zsargo , D. J. Hillier , L. N. Georgiev

Fitting spectral distributions of total fluxes or image intensities are two standard methods for estimating the masses of starless cores and protostellar envelopes. These mass estimates, which are the main source and basis of our knowledge…

Instrumentation and Methods for Astrophysics · Physics 2016-09-28 Alexander Men'shchikov

Diffusion models have achieved outstanding performance in unsupervised industrial anomaly detection (uIAD) by learning a manifold of normal data under the common assumption that off-manifold anomalies are harder to generate, resulting in…

Computer Vision and Pattern Recognition · Computer Science 2026-04-21 Boan Zhang , Wen Li , Guanhua Yu , Xiyang Liu , Wenchao Chen , Long Tian

(Abridged) We describe a new method to extract spectra of stars from observations of crowded stellar fields with integral field spectroscopy (IFS). Our approach extends the well-established concept of crowded field photometry in images into…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Sebastian Kamann , Lutz Wisotzki , Martin M. Roth

When considering particles produced in reactive plasmas, their basic properties, such as refractive index and grain size often need to be known. They can be constrained both ex-situ, e.g., by microscopy, and in-situ by polarimetry, i.e.,…

Plasma Physics · Physics 2022-06-28 Julia Kobus , Andreas Petersen , Franko Greiner , Sebastian Wolf

We propose a novel modulation scheme for intensity modulation and direct detection (IM/DD) based optical communication system employing orthogonal frequency division multiplexing (OFDM). This method utilizes the DC-bias, which typically is…

Information Theory · Computer Science 2014-10-28 Qian Gao , Chen Gong , Rui Wang , Zhengyuan Xu , Yingbo Hua

The use of 3D hydrodynamical simulations of stellar surface convection for model atmospheres is computationally expensive. Although these models have been available for quite some time, their use is limited because of the lack of extensive…

Solar and Stellar Astrophysics · Physics 2022-05-25 S. Bertran de Lis , C. Allende Prieto , H. -G. Ludwig , L. Koesterke

The thermal emission of dust is one of the most important tracers of the interstellar medium: multi-wavelength photometry in the far-infrared (FIR) and submillimeter (submm) can be fitted with a model, providing estimates of the dust mass.…

Astrophysics of Galaxies · Physics 2020-10-07 Lapo Fanciullo , Francisca Kemper , Peter Scicluna , Thavisha E. Dharmawardena , Sundar Srinivasan

The Doppler beaming effect, induced by the reflex motion of stars, introduces flux modulations and serves as an efficient method to photometrically determine mass functions for a large number of close binary systems, particularly those…

Solar and Stellar Astrophysics · Physics 2024-08-08 Chuanjie Zheng , Yang Huang , Jifeng Liu , Youjun Lu , Henggeng Han , Yuan Tan , Timothy C. Beers