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Related papers: Accretion Stream Mapping

200 papers

We present our second paper describing multi-wave-band, time-resolved spectroscopy of WZ Sge. We analyze the evolution of both optical and IR emission lines throughout the orbital period and find evidence, in the Balmer lines, for an…

Astrophysics · Physics 2015-06-24 E. Mason , W. Skidmore , S. B. Howell , D. R. Ciardi , S. Littlefair , V. S. Dhillon

We present a wavelet-based dual-stream network that addresses color cast and blurry details in underwater images. We handle these artifacts separately by decomposing an input image into multiple frequency bands using discrete wavelet…

Computer Vision and Pattern Recognition · Computer Science 2022-04-28 Ziyin Ma , Changjae Oh

Previous research centered on the hydrodynamics in X-ray pulsar accretion columns has largely focused on the single-fluid model, in which the super-Eddington luminosity inside the column decelerates the flow to rest at the stellar surface.…

High Energy Astrophysical Phenomena · Physics 2017-02-01 Brent F. West , Kenneth D. Wolfram , Peter A. Becker

Currently existing energy-stable parametric finite element methods for surface diffusion flow and other flows are usually limited to first-order accuracy in time. Designing a high-order algorithm for geometric flows that can also be…

Numerical Analysis · Mathematics 2024-07-15 Meng Li , Yihang Guo , Jingjiang Bi

Standard diffuse approximations of the Willmore flow often lead to intersecting phase boundaries that in many cases do not correspond to the intended sharp interface evolution. Here we introduce a new two-variable diffuse approximation that…

Analysis of PDEs · Mathematics 2019-11-01 Andreas Rätz , Matthias Röger

In the past few years more and more pieces of evidence have been presented for a revision of the widely accepted Unified Model of Active Galactic Nuclei. A model based solely on orientation cannot explain all the observed phenomenology. In…

Cosmology and Nongalactic Astrophysics · Physics 2015-06-03 Andrea Marinucci , Stefano Bianchi , Fabrizio Nicastro , Giorgio Matt , Andy D. Goulding

Discrete flow mapping was recently introduced as an efficient ray based method determining wave energy distributions in complex built up structures. Wave energy densities are transported along ray trajectories through polygonal mesh…

Computational Physics · Physics 2016-12-21 Janis Bajars , David Chappell , Niels Sondergaard , Gregor Tanner

In the past few years, the Event Horizon Telescope (EHT) has provided the first-ever event horizon-scale images of the supermassive black holes (BHs) (M87*) and Sagittarius A$^*$ (Sgr A*). The next-generation EHT project is an extension of…

A radiative transfer method for the treatment of molecular lines is presented. We apply this method to previous SWAS and ISO observations of water vapor in the source S140 in order to make models to plan for, and to interpret, HIFI data.…

Astrophysics · Physics 2009-11-11 D. R. Poelman , M. Spaans

This work introduces a generalized characteristic mapping method designed to handle non-linear advection with source terms. The semi-Lagrangian approach advances the flow map, incorporating the source term via the Duhamel integral. We…

Numerical Analysis · Mathematics 2026-02-25 Xi-Yuan Yin , Philipp Krah , Jean-Christophe Nave , Kai Schneider

This paper enhances the Diffuse Interface Method (DIM) for simulating compressible multiphase flows across all Mach numbers by addressing the accuracy challenges posed at low Mach regimes. A correction to the Riemann solver is introduced,…

Numerical Analysis · Mathematics 2025-03-17 Ghanshyam Bharate , J. C. Mandal

In this paper, we propose a novel method to precisely match two aerial images that were obtained in different environments via a two-stream deep network. By internally augmenting the target image, the network considers the two-stream with…

Computer Vision and Pattern Recognition · Computer Science 2020-02-05 Jae-Hyun Park , Woo-Jeoung Nam , Seong-Whan Lee

This paper presents a convergence analysis for the Hessian Discretisation Method (HDM) applied to fourth-order semilinear elliptic equations involving a trilinear nonlinearity and general source, based on two complementary approaches. The…

Numerical Analysis · Mathematics 2026-04-14 Devika Shylaja

The physical world consists of spatially varying media, such as the atmosphere and the ocean, in which light and sound propagates along non-linear trajectories. This presents a challenge to existing ray-tracing based methods, which are…

Graphics · Computer Science 2014-09-16 Qi Mo , Hengchin Yeh , Dinesh Manocha

The Event Horizon Telescope (EHT) has produced images of two supermassive black holes, Messier~87* (M 87*) and Sagittarius~A* (Sgr A*). The EHT collaboration used these images to indirectly constrain black hole parameters by calibrating…

High Energy Astrophysical Phenomena · Physics 2022-11-30 Daniel C. M Palumbo , Zachary Gelles , Paul Tiede , Dominic O. Chang , Dominic W. Pesce , Andrew Chael , Michael D. Johnson

A planetary growth rate, a.k.a., the mass accretion rate, is a fundamental parameter in planet formation, as it determines a planet's final mass. Planetary mass accretion rates have been estimated using hydrogen lines, based on the models…

Earth and Planetary Astrophysics · Physics 2024-11-20 Jun Hashimoto , Yuhiko Aoyama

We present StreamNet, an autoencoder architecture for the analysis of the highly heterogeneous geometry of large collections of white matter streamlines. This proposed framework takes advantage of geometry-preserving properties of the…

Quantitative Methods · Quantitative Biology 2022-10-20 Andrew Lizarraga , Katherine L. Narr , Kirsten A. Donald , Shantanu H. Joshi

U Gem is unique in having a direct measurement of K1 = 107 +- 2 km/s, Long et al. 1999). We present high-resolution optical spectra of the dwarf nova U Gem in quiescence taken to test the accuracy to which the HST value can be recovered…

Astrophysics · Physics 2009-11-11 E. Unda-Sanzana , T. R. Marsh , L. Morales-Rueda

Plasma discharge lamps are widely utilized in the practice of angle-resolved photoemission spectroscopy (ARPES) experiments as narrow-linewidth ultraviolet photon sources. However, many emission lines such as Ar-I, Ne-I, and Ne-II have…

Instrumentation and Detectors · Physics 2023-03-15 Yaoju Tarn , Mekhola Sinha , Christopher Pasco , Darrell G. Schlom , Tyrel M. McQueen , Kyle M. Shen , Brendan D. Faeth

Two-stream radiative transfer is a workhorse in the Earth, planetary and exoplanetary sciences due to its simplicity and ease of implementation. However, a longstanding limitation of the two-stream approximation is its inaccuracy in the…

Earth and Planetary Astrophysics · Physics 2018-08-08 Kevin Heng , Matej Malik , Daniel Kitzmann