Related papers: Statistically-derived flaring chromospheric-corona…

The detailed knowledge of plasma heating and acceleration region properties presents a major observational challenge in solar flare physics. Using the Ramaty High Energy Solar Spectroscopic Imager (RHESSI), the high temperature differential…

X-ray and EUV observations are an important diagnostic of various plasma parameters of the solar atmosphere during solar flares. Soft X-ray and EUV observations often show coronal sources near the top of flaring loops, while hard X-ray…

Observations of solar flares with RHESSI have shown X-ray sources traveling along flaring loops, from the corona down to the chromosphere and back up. The 28 November 2002 C1.1 flare, first observed with RHESSI by Sui et al. 2006 and…

A novel method of using hard X-rays as a diagnostic for chromospheric density and magnetic structures is developed to infer sub-arcsecond vertical variation of magnetic flux tube size and neutral gas density.Using Reuven Ramaty High Energy…

Solar flare hard X-rays (HXRs) are produced as bremsstrahlung when an accelerated population of electrons interacts with the dense chromospheric plasma. HXR observations presented by using the Ramaty High-Energy Solar Spectroscopic Imager…

Flares close to the solar limb, where the footpoints are occulted, can reveal the spectrum and structure of the coronal loop-top source in X-rays. We aim at studying the properties of the corresponding energetic electrons near their…

The energy released during solar flares is believed to be stored in non-potential magnetic fields associated with electric currents flowing in the corona. While no measurements of coronal electric currents are presently available, maps of…

The thick-target model predicts that in flare foot points, we should observe lowering of HXR sources' altitude with increasing energy. The foot point of HXR sources result from the direct interaction of non-thermal electron beams with…

We report the detection of emission from a non-thermal electron distribution in a small solar microflare (GOES class A5.7) observed by the Nuclear Spectroscopic Telescope Array (NuSTAR), with supporting observation by the Reuven Ramaty High…

We analyse the spatial distribution and vertical stratification of the physical parameters of the solar atmosphere when an X-class flare occurs. We made use of observations acquired by the Interferometric Bidimensional Spectropolarimeter…

We present new RHESSI upper limits in the 3-200 keV energy range for solar hard X-ray emission in the absence of flares and active regions, i.e. the quiet Sun, using data obtained between July 2005 and April 2009. These new limits,…

The origin of the near-ultraviolet and optical continuum radiation in flares is critical for understanding particle acceleration and impulsive heating in stellar atmospheres. Radiative-hydrodynamic simulations in 1D have shown that high…

We report observations of white-light ejecta in the low corona, for two X-class flares on the 2013 May 13, using data from the Helioseismic and Magnetic Imager (HMI) of the Solar Dynamics Observatory. At least two distinct kinds of sources…

The bulk of solar flare emission originates from very compact sources located in the lower solar atmosphere and seen in various wavelength ranges: near optical, UV, EUV, soft and hard X-rays, and gamma-ray emission, yet very few spatially…

In previous works we have developed a method to convert solar X-ray data, collected with the Yohkoh/SXT, into templates of stellar coronal observations. Here we apply the method to several solar flares, for comparison with stellar X-ray…

We describe observations of a white-light flare (SOL2011-02-24T07:35:00, M3.5) close to the limb of the Sun, from which we obtain estimates of the heights of the optical continuum sources and those of the associated hard X-ray sources.For…

We use RHESSI high-resolution imaging and spectroscopy observations from ~6 to 100 keV to determine the statistical relationships between measured parameters (temperature, emission measure, etc.) of hot, thermal plasma in 37 intense (GOES…

A M-class behind-the-limb solar flare on 1 May 2013 (SOL2013-05-01T02:32), accompanied by a ($\sim$ 400 km/s) CME was observed by several space-based observatories with different viewing angles. We investigated the RHESSI-observed occulted…

Context: Solar flares release a large fraction of their energy into non-thermal electrons, but it is not clear where and how. Bremsstrahlung X-rays are observed from the corona and chromosphere. Aims: We aim to characterize the acceleration…

Red-shifted components of chromospheric emission lines in the hard X-ray impulsive phase of solar flares have recently been studied through their 30 s evolution with the high resolution of IRIS. Radiative-hydrodynamic flare models show that…