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The aim of the thesis is the study of properties of solar flares via reconstruction of energy distributions of accelerated/heated electrons, diagnostics of flare plasma based on EUV and X-ray observations, as well as the estimation of the…

Solar and Stellar Astrophysics · Physics 2017-10-31 Galina G. Motorina

It is generally accepted that densities of quiet sun and active region plasma are sufficiently low to justify the optically thin approximation, and it is commonly used in the analysis of line emissions from plasma in the solar corona.…

Solar and Stellar Astrophysics · Physics 2018-02-14 Edward Thiemann , Phillip Chamberlin , Francis Eparvier , Luke Epp

Solar flares result in an increase of the solar irradiance at all wavelengths. While the distribution of the flare fluence observed in coronal emission has been widely studied and found to scale as f(E) ~ E^{-\alpha}, with \alpha slightly…

Solar and Stellar Astrophysics · Physics 2015-10-08 M. Kretzschmar

The extreme ultraviolet portion of the solar spectrum contains a wealth of diagnostic tools for probing the lower solar atmosphere in response to an injection of energy, particularly during the impulsive phase of solar flares. These include…

Solar and Stellar Astrophysics · Physics 2015-09-16 Ryan O. Milligan

Data from the Multiple EUV Grating Spectrograph (MEGS-A) component of the Extreme Ultraviolet Experiment (EVE) onboard the Solar Dynamics Observatory (SDO) were used to quantify the contribution of continuum emission to each of the EUV…

Solar and Stellar Astrophysics · Physics 2015-06-16 Ryan O. Milligan , Sarah A. McElroy

Previously-unexplored diagnostics of O IV in the extreme ultraviolet region 260-280 A are used to derive a temperature and density for a solar flare kernel observed on 2012 March 9 with the Extreme ultraviolet Imaging Spectrometer on the…

Solar and Stellar Astrophysics · Physics 2024-01-24 Peter R. Young

We present an analysis of soft X-ray (SXR) and extreme-ultraviolet (EUV) observations of solar flares with an approximate C8 GOES class. Our constraint on peak GOES SXR flux allows for the investigation of correlations between various flare…

Solar and Stellar Astrophysics · Physics 2013-05-09 Trevor A. Bowen , Paola Testa , Katharine K. Reeves

The hydrogen Lyman lines provide important diagnostic information about the dynamics of the chromosphere, but there have been few systematic studies of their variability during flares. We investigate Doppler shifts in these lines in several…

Solar and Stellar Astrophysics · Physics 2016-11-30 Stephen A Brown , Lyndsay Fletcher , Nicolas Labrosse

This thesis strives to improve our understanding of solar activity, specifically the behaviour of solar flares and coronal mass ejections. An investigation into the hydrodynamic evolution of a confined solar flare was carried out using…

Solar and Stellar Astrophysics · Physics 2012-10-19 Claire L. Raftery

X-Ray and Ultraviolet (UV) observations of the outer solar atmosphere have been used for many decades to measure the fundamental parameters of the solar plasma. This review focuses on the optically thin emission from the solar atmosphere,…

Solar and Stellar Astrophysics · Physics 2018-09-06 Giulio Del Zanna , Helen E. Mason

In addition to X-rays, extreme ultraviolet (EUV) rays radiated from solar flares can cause serious problems, such as communication failures and satellite drag. Therefore, methods for forecasting EUV dynamic spectra during flares are…

Solar and Stellar Astrophysics · Physics 2020-05-14 Toshiki Kawai , Shinsuke Imada , Shohei Nishimoto , Kyoko Watanabe , Tomoko Kawate

The properties of solar flare plasma can be determined from the observation of optically thin lines. The emitting ion distribution determines the shape of the line, with an isothermal Maxwellian ion distribution producing a Gaussian…

Solar and Stellar Astrophysics · Physics 2016-05-25 Natasha Jeffrey , Lyndsay Fletcher , Nicolas Labrosse

Daily differential emission measure (DEM) distributions of the solar corona are derived from spectra obtained by the Extreme-ultraviolet Variability Experiment (EVE) over a 4-year period starting in 2010 near solar minimum and continuing…

Solar and Stellar Astrophysics · Physics 2020-09-16 Samuel J. Schonfeld , Stephen M. White , Rachel A. Hock-Mysliwiec , R. T. James McAteer

The Solar Aspect Monitor (SAM) is a pinhole camera on the Extreme-ultraviolet Variability Experiment (EVE) aboard the Solar Dynamics Observatory (SDO). SAM projects the solar disk onto the CCD through a metallic filter designed to allow…

Solar and Stellar Astrophysics · Physics 2016-05-27 C. Y. Lin , S. M. Bailey , A. Jones , D. Woodraska , A. Caspi , T. N. Woods , F. G. Eparvier , S. R. Wieman , L. V. Didkovsky

The Extreme ultraviolet SpectroPhotometer (ESP) is one of five channels of the Extreme ultraviolet Variability Experiment (EVE) onboard the NASA Solar Dynamics Observatory (SDO). The ESP channel design is based on a highly stable…

Solar and Stellar Astrophysics · Physics 2015-05-14 Leonid Didkovsky , Darrell Judge , Seth Wieman , Tom Woods , Andrew Jones

This paper investigates the temporal evolution of temperature, emission measure, energy loss and velocity in a C-class solar flare from both an observational and theoretical perspective. The properties of the flare were derived by following…

Astrophysics · Physics 2009-11-13 Claire L. Raftery , Peter T. Gallagher , Ryan O. Milligan , James A. Klimchuk

We benchmark new atomic data against a selection of irradiances obtained from medium-resolution quiet Sun spectra in the EUV, from 60 to 1040 \AA. We use as a baseline the irradiances measured during solar minimum on 2008 April 14 by the…

Solar and Stellar Astrophysics · Physics 2019-04-03 G. Del Zanna

The solar irradiance in the Extreme Ultraviolet (EUV) spectral bands has been observed with a 15 sec cadence by the SOHO Solar EUV Monitor (SEM) since 1995. During remarkably intense solar flares the SEM EUV measurements are saturated in…

Astrophysics · Physics 2009-11-11 L. V. Didkovsky , D. L. Judge , A. R. Jones , S. Wieman , B. T. Tsurutani , D. McMullin

This paper presents a detailed study of excess line broadening in EUV emission lines during the impulsive phase of a C-class solar flare. In this work, which utilizes data from the EUV Imaging Spectrometer (EIS) onboard Hinode, the…

Solar and Stellar Astrophysics · Physics 2012-02-09 Ryan O. Milligan

The Extreme-ultraviolet Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO) detects the solar EUV spectra with high temporal cadence and spectral resolution. The wavelength shifts of emission lines provide key…

Solar and Stellar Astrophysics · Physics 2021-04-21 Zhixun Cheng , Yuming Wang , Rui Liu