相关论文: Hot Plasma in Non-Flaring Active Regions Observed …
We analyse the coronal elemental abundances during a small flare using Hinode/EIS observations. Compared to the pre-flare elemental abundances, we observed a strong increase in coronal abundance of Ca XIV 193.84 {\AA}, an emission line with…
Plasma flows within prominences/filaments have been observed for many years and hold valuable clues concerning the mass and energy balance within these structures. Previous observations of these flows primarily come from H-alpha and cool…
EUV imaging observations from several space missions (SOHO/EIT, TRACE, and SDO/AIA) have revealed a presence of propagating intensity disturbances in solar coronal loops. These disturbances are typically interpreted as slow magnetoacoustic…
We show that the Fe XVII I(17.10 A)/I(17.05 A) line ratio observed in the Chandra HETG spectrum of the intermediate polar EX Hydrae is significantly smaller than that observed in the Sun or other late-type stars. Using the Livermore X-ray…
The \textit{High resolution Coronal Imager (Hi-C)} has provided the sharpest view of the EUV corona to date. In this paper we exploit its impressive resolving power to provide the first analysis of the fine-scale structure of moss in an…
We have calculated the H$\alpha$ and Ca {\sc ii} 8542 {\AA} line profiles based on four different atmospheric models, including the effects of nonthermal electron beams with various energy fluxes. These two lines have different responses to…
Long-lasting, intense, stellar X-ray flares may approach conditions of breaking magnetic confinement and evolving in open space. We explore this hypothesis with hydrodynamic simulations of flares occurring in a non-confined corona: model…
The plasma of the solar corona harbors a multitude of coronal wave modes, some of which could be dissipated to provide the required energy and momentum to heat the corona and accelerate the solar wind. We present observations of the corona…
Solar active regions contain a broad range of temperatures, with the thermal plasma distribution often observed to peak in the few millions of kelvin. Differential emission measure (DEM) analysis can allow instruments with diverse…
We investigate the heating of an erupting prominence and loops associated with a coronal mass ejection and X-class flare. The prominence is seen in absorption in EUV at the beginning of its eruption. Later the prominence changes to…
We study plasma flows along selected coronal loops in NOAA Active Region 10926, observed on 3 December 2006 with Hinode's EUV Imaging Spectrograph (EIS). From the shape of the loops traced on intensity images and the Doppler shifts measured…
The energy released in a solar flare is partitioned between thermal and non-thermal particle energy and lost to thermal conduction and radiation over a broad range of wavelengths. It is difficult to determine the conductive losses and the…
Observational measurements of active region emission measures contain clues to the time-dependence of the underlying heating mechanism. A strongly non-linear scaling of the emission measure with temperature indicates a large amount of hot…
We present new HST-COS G130M spectroscopy for a sightline toward a filament projected 1.9 kpc from the nucleus of M87. The combination of the sensitivity of COS and the proximity of M87 allows us to study the structure of this filament in…
We have used the Extreme Ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft to observe large areas of outflow near an active region. These outflows are seen to persist for at least 6 days. The emission line profiles suggest…
Magnetohydrodynamic (MHD) waves and/or the braiding of magnetic field lines are largely thought to be responsible for heating the solar corona, both being mechanisms which are driven by the Sun's photospheric magnetic field. Recent…
We have previously found a temperature-dependent upflow in the dimming region following a coronal mass ejection (CME) observed by the {\it Hinode} EUV Imaging Spectrometer (EIS). In this paper, we reanalyzed the observations along with…
The intensity of the \oiv~2s$^{2}$ 2p $^{2}$P-2s2p$^{2}$ $^{4}$P and \siv~3 s$^{2}$ 3p $^{2}$P- 3s 3p$^{2}$ $^{4}$ P intercombination lines around 1400~\AA~observed with the \textit{Interface Region Imaging Spectrograph} (IRIS) provide a…
We present He-like line ratios (resonance, intercombination and forbidden lines) for totally and partially photoionized media. For solar plasmas, these line ratios are already widely used for density and temperature diagnostics of coronal…
It has previously been argued that 1. spicules do not provide enough pre-heated plasma to fill the corona, and 2. even if they did, additional heating would be required to keep the plasma hot as it expands upward. We here address the…