English
Related papers

Related papers: Sparse Bayesian Imaging of Solar Flares

200 papers

One way of imaging X-ray emission from solar flares is to measure Fourier components of the spatial X-ray source distribution. We present a new Compressed Sensing-based algorithm named VIS_CS, which reconstructs the spatial distribution…

Solar and Stellar Astrophysics · Physics 2017-11-01 Simon Felix , Roman Bolzern , Marina Battaglia

Solar flares are large-scale releases of energy in the solar atmosphere, which are characterised by rapid changes in the hydrodynamic properties of plasma from the photosphere to the corona. Solar physicists have typically attempted to…

Solar and Stellar Astrophysics · Physics 2012-06-26 S. Adamakis , C. L. Raftery , R. W. Walsh , P. T. Gallagher

Flares are a well-studied aspect of the Sun's magnetic activity. Detecting and classifying solar flares can inform the analysis of contamination caused by stellar flares in exoplanet transmission spectra. In this paper, we present a…

Solar and Stellar Astrophysics · Physics 2024-06-25 Nicole Hao , Laura Flagg , Ray Jayawardhana

The degree of linear polarization in solar flares has not yet been precisely determined despite multiple attempts to measure it with different missions. The high energy range in particular has very rarely been explored, due to its greater…

Astrophysics · Physics 2009-11-11 E. Suarez-Garcia , W. Hajdas , C. Wigger , K. Arzner , M. Guedel , A. Zehnder , P. Grigis

In this paper we present new optimization strategies for the reconstruction of X-ray images of solar flares by means of the data collected by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI). The imaging concept of the…

Instrumentation and Methods for Astrophysics · Physics 2014-06-26 S. Bonettini , M. Prato

We present an overview of solar flares and associated phenomena, drawing upon a wide range of observational data primarily from the RHESSI era. Following an introductory discussion and overview of the status of observational capabilities,…

We present a new analytical technique, combining Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI) high-resolution imaging and spectroscopic observations, to visualize solar flare emission as a function of spectral component…

Instrumentation and Methods for Astrophysics · Physics 2015-09-15 Amir Caspi , Albert Y. Shih , James M. McTiernan , Säm Krucker

We present a concept for a machine-learning classification of hard X-ray (HXR) emissions from solar flares observed by the Reuven Ramaty High Energy Solar Spectroscopic Imager (RHESSI), identifying flares that are either occulted by the…

Solar and Stellar Astrophysics · Physics 2021-02-24 Shin-nosuke Ishikawa , Hideaki Matsumura , Yasunobu Uchiyama , Lindsay Glesener

We present a principled Bayesian framework for signal reconstruction, in which the signal is modelled by basis functions whose number (and form, if required) is determined by the data themselves. This approach is based on a Bayesian…

Instrumentation and Methods for Astrophysics · Physics 2019-01-23 Edward Higson , Will Handley , Michael Hobson , Anthony Lasenby

A number of methods of flare prediction rely on classification of physical characteristics of an active region, in particular optical classification of sunspots, and historical rates of flaring for a given classification. However these…

Astrophysics · Physics 2009-11-10 M. S. Wheatland

Image super-resolution (SR) is one of the long-standing and active topics in image processing community. A large body of works for image super resolution formulate the problem with Bayesian modeling techniques and then obtain its…

Computer Vision and Pattern Recognition · Computer Science 2012-09-20 Haichao Zhang , David Wipf , Yanning Zhang

Current analysis of astronomical data are confronted with the daunting task of modeling the awkward features of astronomical data, among which heteroscedastic (point-dependent) errors, intrinsic scatter, non-ignorable data collection…

Instrumentation and Methods for Astrophysics · Physics 2011-12-19 S. Andreon

Polarization measurements of hard X-rays from solar flares can provide a direct handle on the extent to which the accelerated electrons are beamed, which, in turn, has important implications for particle acceleration models. Past efforts to…

Astrophysics · Physics 2009-11-07 M. L. McConnell , J. M. Ryan , D. M. Smith , R. P. Lin , A. G. Emslie

Machine learning techniques have been successfully applied to super-resolution tasks on natural images where visually pleasing results are sufficient. However in many scientific domains this is not adequate and estimations of errors and…

The Reuven Ramaty High Energy Spectroscopic Solar Imager (RHESSI) uses the rotational modulation principle to observe temporally, spatially, and spectrally resolved hard X ray and gamma ray images of solar flares. In order to track the…

Astrophysics · Physics 2009-11-10 Kaspar Arzner

We present and implement a probabilistic (Bayesian) method for producing catalogs from images of stellar fields. The method is capable of inferring the number of sources N in the image and can also handle the challenges introduced by noise,…

Instrumentation and Methods for Astrophysics · Physics 2015-06-12 Brendon J. Brewer , Daniel Foreman-Mackey , David W. Hogg

Image reconstruction based on indirect, noisy, or incomplete data remains an important yet challenging task. While methods such as compressive sensing have demonstrated high-resolution image recovery in various settings, there remain issues…

Numerical Analysis · Mathematics 2023-03-07 Jan Glaubitz , Anne Gelb , Guohui Song

We describe regularized methods for image reconstruction and focus on the question of hyperparameter and instrument parameter estimation, i.e. unsupervised and myopic problems. We developed a Bayesian framework that is based on the \post…

Instrumentation and Methods for Astrophysics · Physics 2012-11-16 F. Orieux , J. -F. Giovannelli , T. Rodet , A. Abergel

We present a Bayesian-odds-ratio-based algorithm for detecting stellar flares in light curve data. We assume flares are described by a model in which there is a rapid rise with a half-Gaussian profile, followed by an exponential decay. Our…

Solar and Stellar Astrophysics · Physics 2015-06-19 M. Pitkin , D. Williams , L. Fletcher , S. D. T. Grant

One of the big challenges in astrophysics is the comparison of complex simulations to observations. As many codes do not directly generate observables (e.g. hydrodynamic simulations), the last step in the modelling process is often a…

Instrumentation and Methods for Astrophysics · Physics 2018-05-08 Frederik Beaujean , Hans C. Eggers , Wolfgang E. Kerzendorf
‹ Prev 1 2 3 10 Next ›