Related papers: Active region transition region loop populations a…
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…
Previous solar observations have shown that coronal loops near 1 MK are difficult to reconcile with simple heating models. These loops have lifetimes that are long relative to a radiative cooling time, suggesting quasi-steady heating. The…
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…
I report on observations of a set of magnetic loops above a region with late-phase flux emergence taken by IRIS, Hinode and SDO. The loop system consists of many transition region loop threads with size of 5--12\arcsec\ in length and…
The evolution of a coronal loop is studied by means of numerical simulations of the fully compressible three-dimensional magnetohydrodynamic equations using the HYPERION code. The footpoints of the loop magnetic field are advected by random…
Coronal loops are plasma structures in the solar atmosphere with temperatures reaching millions of Kelvin, shaped and sustained by the magnetic field. However, their morphology and fundamental nature remain subjects of debate. By studying…
We present observations of high temperature emission in the core of a solar active region using instruments on Hinode and SDO. These multi-instrument observations allow us to determine the distribution of plasma temperatures and follow the…
We investigate the relative contributions from the transition region and corona of coronal loops observed by the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO). Using EBTEL (Enthalpy-Based Thermal Evolution of…
Loops are fundamental structures in the magnetized atmosphere of the sun. Their physical properties are crucial for understanding the nature of the solar atmosphere. Transition region loops are relatively dynamic and their physical…
The high densities, long lifetimes, and narrow emission measure distributions observed in coronal loops with apex temperatures near 1 MK are difficult to reconcile with physical models of the solar atmosphere. It has been proposed that the…
A complete understanding of Doppler shift in active region loops can help probe the basic physical mechanism involved into the heating of those loops. Here we present observations of upflows in coronal loops detected in a range of…
How the solar corona is heated to high temperatures remains an unsolved mystery in solar physics. In the present study we analyse observations of 50 whole active-region loops taken with the Extreme-ultraviolet Imaging Spectrometer (EIS) on…
Coronal loops are fundamental building blocks of the solar active regions and the corona. Therefore, a clear understanding of the physics of coronal loops will help us understand the physics of active region heating in particular and…
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…
Using Hinode EUV Imaging Spectrometer (EIS) spectra recorded daily at Sun center from the end of 2006 to early 2011, we studied the long-term evolution of the quiet corona. The light curves of the higher temperature emission lines exhibit…
Coronal loop oscillations are common phenomena in the solar corona, which are often classified as decaying and decayless oscillations. Using the high-resolution observation measured by the Extreme Ultraviolet Imager (EUI) onboard the Solar…
Two types of active region feature prominent at transition region temperatures are identified in Hinode/EIS data of AR 10938 taken on 2007 January 20. The footpoints of 1 MK TRACE loops are shown to emit strongly in emission lines formed at…
We report on the first Interface Region Imaging Spectrograph (IRIS) study of cool transition region loops. This class of loops has received little attention in the literature. A cluster of such loops was observed on the solar disk in active…
We present a study of the temporal evolution of coronal loops in active regions and its implications for the dynamics in coronal loops. We analyzed images of the Atmospheric Imaging Assembly (AIA) on the Solar Dynamics Observatory (SDO) at…
We present the first Hinode/EIS observations of 5 min quasi-periodic oscillations detected in a transition-region line (He II) and five coronal lines (Fe X, Fe XII, Fe XIII, Fe XIV, and Fe XV) at the footpoint of a coronal loop. The…