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One of the primary science objectives of Parker Solar Probe (PSP) is to determine the structures and dynamics of the plasma and magnetic fields at the sources of the solar wind. However, establishing the connection between {\it in situ}…

The paper presents the results from a multi-year effort to develop and validate image processing methods for selecting the best physical models based on solar image observations. The approach consists of selecting the physical models based…

Image and Video Processing · Electrical Eng. & Systems 2022-01-06 V. Jatla , M. S. Pattichis , C. N. Arge

We search for signatures of high-frequency oscillations in the upper solar photosphere and low chromosphere in the context of acoustic heating of outer stellar atmospheres. We use ultraviolet image sequences of a quiet center-disk area from…

Astrophysics · Physics 2009-06-23 A. G. de Wijn , R. J. Rutten , T. D. Tarbell

We consider the problem of estimating a spatially varying density function, motivated by problems that arise in large-scale radiological survey and anomaly detection. In this context, the density functions to be estimated are the background…

Methodology · Statistics 2017-11-17 Wesley Tansey , Alex Athey , Alex Reinhart , James G. Scott

We undertake a first attempt towards a consistent reconstruction of the coronal magnetic field and the coronal density structure. We consider a stationary solar corona which has to obey the equations of magnetohydrostatics. We solve these…

Astrophysics · Physics 2009-06-25 T. Wiegelmann , B. Inhester

The solar corona is a highly-structured plasma which can reach temperatures of more than ~2 MK. At low frequencies (decimetric and metric wavelengths), scattering and refraction of electromagnetic waves are thought to considerably increase…

The atmosphere of the Sun is highly structured and dynamic in nature. From the photosphere and chromosphere into the transition region and the corona plasma-$\beta$ changes from above to below one, i.e. while in the lower atmosphere the…

Astrophysics · Physics 2008-11-26 H. Peter

Solar rotational tomography (SRT) applied to white-light coronal images observed at multiple aspect angles has been the preferred approach for determining the three-dimensional (3D) electron density structure of the solar corona. However,…

Solar and Stellar Astrophysics · Physics 2016-10-04 Didier Vibert , Christelle Peillon , Philippe Lamy , Richard A. Frazin , Julien Wojak

This paper presents some of the main aspects of the software library that has been developed for the reduction of optical and infrared images, an integral part of the end-to-end survey system being built to support public imaging surveys at…

Astrophysics · Physics 2009-11-07 Benoit Vandame

For the purpose of investigating the differential rotation of the solar corona, we analyzed ultraviolet (UV) spectral line observations acquired on both the east and west limbs at 1.7 $R_{\odot}$ by SOHO/UVCS during the solar minimum…

Solar and Stellar Astrophysics · Physics 2020-11-25 S. Mancuso , S. Giordano , D. Barghini , D. Telloni

Spectroscopic observations at extreme and far ultraviolet wavelengths have revealed systematic upflows in the solar transition region and corona. These upflows are best seen in the network structures of the quiet Sun and coronal holes,…

Solar and Stellar Astrophysics · Physics 2021-03-17 Hui Tian , Louise Harra , Deborah Baker , David H. Brooks , Lidong Xia

Current state-of-the-art spectrographs cannot resolve the fundamental spatial (sub-arcseconds) and temporal scales (less than a few tens of seconds) of the coronal dynamics of solar flares and eruptive phenomena. The highest resolution…

Understanding the initiation of solar flares and coronal mass ejections (CMEs) is essential for improving forecasts of extreme space weather. Soft X-ray (SXR) and Extreme Ultraviolet (EUV) observations provide critical diagnostics of the…

Coronal waves are large-scale disturbances often driven by coronal mass ejections (CMEs). We investigate a spectacular wave event on 7 March 2012, which is associated with an X5.4 flare (SOL2012-03-07). By using a running center-median…

Solar and Stellar Astrophysics · Physics 2020-11-04 Li Feng , Lei Lu , Bernd Inhester , Joseph Plowman , Beili Ying , Marilena Mierla , Matthew J. West , Weiqun Gan

We aim to reproduce the structure of the corona above a solar active region as seen in the extreme ultraviolet (EUV) using a three-dimensional magnetohydrodynamic (3D MHD) model. The 3D MHD data-driven model solves the induction equation…

Solar and Stellar Astrophysics · Physics 2019-04-30 Jörn Warnecke , Hardi Peter

8000 images of the Solar corona were captured during the June 2001 total Solar eclipse. New software for the alignment of the images and an automated technique for detecting intensity oscillations using multi scale wavelet analysis were…

Astrophysics · Physics 2009-11-10 A. C. Katsiyannis , F. Murtagh

How and where are coronal loops rooted in the solar lower atmosphere? The details of the magnetic environment and its evolution at the footpoints of coronal loops are crucial to understanding the processes of mass and energy supply to the…

Deciphering and understanding the small-scale magnetic activity of the quiet solar photosphere should help to solve many of the key problems of solar and stellar physics, such as the magnetic coupling to the outer atmosphere and the coronal…

Astrophysics · Physics 2007-05-23 J. Trujillo Bueno , N. Shchukina , A. Asensio Ramos

During non-flaring times, the radio flux of the Sun at the wavelength of a few centimeters to several tens of centimeters mostly originates from the thermal bremsstrahlung emission, very similar to the EUV radiation. Owing to such a…

Solar and Stellar Astrophysics · Physics 2020-03-11 Z. F. Li , S. H. Hua , X. Cheng , M. D. Ding

Inversion codes allow reconstructing a model atmosphere from observations. With the inclusion of optically thick lines that form in the solar chromosphere, such modelling is computationally very expensive because a non-LTE evaluation of the…

Solar and Stellar Astrophysics · Physics 2019-04-19 Alberto Sainz Dalda , Jaime de la Cruz Rodríguez , Bart De Pontieu , Milan Gošić