Related papers: Temperature distribution of a non-flaring active r…
In previous studies a very hot plasma component has been diagnosed in solar active regions through the images in three different narrow-band channels of SDO/AIA. This diagnostic from EUV imaging data has also been supported by the matching…
Nanoflares, short and intense heat pulses within spatially unresolved magnetic strands, are now considered a leading candidate to solve the coronal heating problem. However, the frequent occurrence of nanoflares requires that flare-hot…
We compare observations of the non-flaring solar corona made simultaneously with Hinode/XRT and with RHESSI. The analyzed corona is dominated by a single active region on 12 November 2006. The comparison is made on emission measures. We…
We present observations of transient active region heating events observed with the Extreme Ultraviolet Imaging Spectrometer (EIS) and X-ray Telescope (XRT) on Hinode. This initial investigation focuses on NOAA active region 10940 as…
Using data from the Extreme-ultraviolet Imaging Spectrometer aboard Hinode, we have studied the coronal plasma in the core of two active regions. Concentrating on the area between opposite polarity moss, we found emission measure…
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…
Previous observations have not been able to exclude the possibility that high temperature active region loops are actually composed of many small scale threads that are in various stages of heating and cooling and only appear to be in…
We perform plasma diagnostics, including that of the non-Maxwellian $\kappa$-distributions, in several structures observed in the solar corona by the Extreme-Ultraviolet Imaging Spectrometer (EIS) onboard the Hinode spacecraft. To prevent…
Measuring the relative amount of high-temperature, low-emission-measure plasma is considered to be a smoking gun observation to constrain the frequency of plasma heating in coronal structures. Often, narrowband, extreme ultraviolet images,…
We present new constraints on the high-temperature emission measure of a non-flaring solar active region using observations from the recently flown Focusing Optics X-ray Solar Imager sounding rocket payload. FOXSI has performed the first…
We use coronal imaging observations with SDO/AIA, and Hinode/EIS spectral data, to explore the potential of narrow band EUV imaging data for diagnosing the presence of hot (T >~5MK) coronal plasma in active regions. We analyze observations…
Determining the temperature distribution of coronal plasmas can provide stringent constraints on coronal heating. Current observations with the Extreme ultraviolet Imaging Spectrograph onboard Hinode and the Atmospheric Imaging Assembly…
Measurements of the temperature and density structure of the solar corona provide critical constraints on theories of coronal heating. Unfortunately, the complexity of the solar atmosphere, observational uncertainties, and the limitations…
This paper investigates a quiescent (non-flaring) active region observed on July 13, 2010 in EUV, SXR, and HXRs to search for a hot component that is speculated to be a key signature of coronal heating. We use a combination of RHESSI…
The recent analysis of observations taken with the EIS instrument on Hinode suggests that well constrained measurements of the temperature distribution in solar active regions can finally be made. Such measurements are critical for…
Based on observations from the EUV Imaging Spectrometer (EIS) on board Hinode, the existence of a broad distribution of blue and red Dopplershift in active region loops has been revealed; the distribution of Dopplershifts depends on the…
The temperature distribution of the emitting plasma is a crucial constraint when studying the heating of solar flare footpoints. However, determining this for impulsive phase footpoints has been difficult in the past due to insufficient…
EUV observations of warm coronal loops suggest that they are bundles of unresolved strands that are heated impulsively to high temperatures by nanoflares. The plasma would then have the observed properties (e.g., excess density compared to…
We discuss here various methodologies and an optimal strategy of the temperature and emission measure diagnostics based on Hinode X-Ray Telescope data. As an example of our results we present determination of the temperature distribution of…
The Extreme-ultraviolet Imaging Spectrometer (EIS) on the Hinode spacecraft obtains high resolution spectra of the solar atmosphere in two wavelength ranges: 170 - 210 and 250 - 290 angstroms. These wavelength regions contain a wealth of…