Related papers: Temporal Variability of Active Region Outflows
One of the major discoveries of Hinode's Extreme-ultraviolet Imaging Spectrometer (EIS) is the presence of upflows at the edges of active regions. As active regions are magnetically connected to the large-scale field of the corona, these…
Coronal upflows at the edges of active regions (AR), which are a possible source of slow solar wind, have been found to connect with dynamics in the transition region. To infer at what scale transition region dynamics connect to AR upflows,…
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 exploit the high spatial resolution and high cadence of the Interface Region Imaging Spectrograph (IRIS) to investigate the response of the transition region and chromosphere to energy deposition during a small flare. Simultaneous…
We report the discovery and characterization of high-speed (>100 km/s) horizontal flows in solar active regions, making use of the Sun-as-a-star spectroscopy in the range 5-105 nm provided by the EVE (Extreme Ultraviolet Variability…
Observations of transition region emission in solar active regions represent a powerful tool for determining the properties of hot coronal loops. In this Letter we present the analysis of new observations of active region moss taken with…
The profiles of emission lines formed in the corona contain information on the dynamics and the heating of the hot plasma. Only recently has data with sufficiently high spectral resolution become available for investigating the details 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…
We observed rapid variability ($\lesssim 60$ s) at the footpoints of transient hot ($\sim 8-10$ MK) coronal loops in active region cores, with the Interface Region Imaging Spectrograph (IRIS). The high spatial ($\sim 0.33$ arcsec) and…
Plasma upflows with a Doppler shift exceeding -10 km/s at active region (AR) boundaries are considered potential sources of the nascent slow solar wind. We investigate the driving mechanisms of a pair of coronal upflow regions on the…
Dynamic fibrils (DFs) are commonly observed chromospheric features in solar active regions. Recent observations from the Extreme Ultraviolet Imager (EUI) aboard the Solar Orbiter have revealed unambiguous signatures of DFs at the coronal…
Using detrended fluctuation analysis (DFA) and rescaled range (R/S) analysis, we investigate the scaling properties of EUV intensity fluctuations of low-latitude coronal holes (CHs) and neighboring quiet-Sun (QS) regions in signals obtained…
To study the dynamical evolution of trans-equatorial loops (TELs) using imaging and spectroscopy. We have used the images recorded by the Atmospheric Imaging Assembly and the Helioseismic Magnetic Imager on-board the Solar Dynamics…
It is well-known that extreme ultraviolet emission emitted at the solar surface is absorbed by overlying cool plasma. Especially in active regions dark lanes in EUV images suggest that much of the surface activity is obscured. Simultaneous…
Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal…
We performed a systematic study of 12 active regions (ARs) with a broad range of areas, magnetic flux and associated solar activity in order to determine whether there are upflows present at the AR boundaries and if these upflows exist,…
Transition-region explosive events (EEs) are characterized by non-Gaussian line profiles with enhanced wings at Doppler velocities of 50-150 km/s. They are believed to be the signature of solar phenomena that are one of the main…
Fast outflows and their interaction with slow shells (generally known as the fossil circumstellar envelope of asymptotic giant branch stars) play an important role in the structure and kinematics of protoplanetary and planetary nebulae…
The high temporal, spatial and spectral resolution of Interface Region Imaging Spectrograph (IRIS) has provided new insights into the understanding of different small-scale processes occurring at the chromospheric and transition region (TR)…
Using a full spectral scan of an active region from the Extreme-Ultraviolet Imaging Spectrometer (EIS) we have obtained Emission Measure EM$(T)$ distributions in two different moss regions within the same active region. We have compared…