相关论文: Impulsivity Parameter for Solar Flares

Understanding the physical processes that trigger solar flares is paramount to help with forecasting space weather and mitigating the effects on our technological infrastructure. A previously unknown phenomenon was recently identified in…

Large solar flares (GOES M-class or higher) are usually associated with eruptions of material. However, when considering flare irradiance enhancements and dynamics such as chromospheric evaporation, potential contributions from erupted…

Solar flares are extremely energetic phenomena in our Solar System. Their impulsive, often drastic radiative increases, in particular at short wavelengths, bring immediate impacts that motivate solar physics and space weather research to…

The Fermi Large Area Telescope (LAT) observed two bright X-class solar flares on 2012 March 7, and detected gamma-rays up to 4 GeV. We detected gamma-rays both during the impulsive and temporally-extended emission phases, with emission…

Based on a sample of 1114 flares observed simultaneously in hard X-rays (HXR) by the BATSE instrument and in soft X-rays (SXR) by GOES, we studied several aspects of the Neupert effect and its interpretation in the frame of the…

This paper presents measurements of the energy radiated by the lower solar atmosphere, at optical, UV, and EUV wavelengths, during an X-class solar flare (SOL2011-02-15T01:56) in response to an injection of energy assumed to be in the form…

Solar flares are observed and classified according to their intensity measured with the GOES X-ray Sensors. We show that the duration of a flare, as measured by the full width at half maximum (FWHM) in GOES is not related to the size of the…

Solar flares are powerful particle accelerators, and in the accepted standard flare model most of the flare energy is transported from a coronal energy-release region by accelerated electrons which stop collisionally in the chromosphere,…

Solar flares are transient yet dramatic events in the atmosphere of the Sun, during which a vast amount of magnetic energy is liberated. This energy is subsequently transported through the solar atmosphere or into the heliosphere, and…

[Abridged]We present analysis of a pair of unusually energetic coronal hard X-ray (HXR) sources detected by RHESSI during the impulsive phase of an X3.9 class solar flare on 2003 November 3, which simultaneously shows two intense footpoint…

Solar active regions and the processes that occur in them have been extensively studied and analyzed and many types of models and characterizations have been proposed for the occurrence of different eruptive events that take place in the…

The precise physical process that triggers solar flares is not currently understood. Here we attempt to capture the signature of this mechanism in solar image data of various wavelengths and use these signatures to predict flaring activity.…

This short paper reviews several recent key observations of the processes occurring in the lower atmosphere (chromosphere and photosphere) during flares. These are: evidence for compact and fragmentary structure in the flare chromosphere,…

Following our recent paper (Petrosian & Chen 2010), we have developed an inversion method to determine the basic characteristics of the particle acceleration mechanism directly and non-parametrically from observations under the leaky box…

Impulsive solar energetic-particle (SEP) events were first distinguished as the streaming electrons that produce type III radio bursts as distinct from shock-induced type II bursts. They were then observed as the surprisingly-enhanced…

In our recent paper (Solar Physics 261, 233) we investigated quasi-periodic oscillations of hard X-rays during impulsive phase of solar flares. We have come to conclusion that they are caused by magnetosonic oscillations of magnetic traps…

Solar active regions (ARs) that produce major flares typically exhibit strong plasma shear flows around photospheric magnetic polarity inversion lines (MPILs). It is therefore important to quantitatively measure such photospheric shear…

Solar eruptive events, like flares and coronal mass ejections, are characterized by the rapid release of energy that can give rise to emission of radiation across the entire electromagnetic spectrum and to an abrupt significant increase in…

Non-potential magnetic energy promptly released in solar flares is converted to other forms of energy. This may include nonthermal energy of flare-accelerated particles, thermal energy of heated flaring plasma, and kinetic energy of…

We present a statistical study of chromospheric evaporation in solar flares using simultaneous observations by the RHESSI X-ray telescope and the IRIS UV spectrograph. The results are compared with radiation hydrodynamic flare models from…