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Related papers: Multimodal Differential Emission Measure in the So…

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Solar activity plays a quintessential role in influencing the interplanetary medium and space-weather around the Earth. Remote sensing instruments onboard heliophysics space missions provide a pool of information about the Sun's activity…

We study the spatial distribution and evolution of the slope of the Emission Measure between 1 and 3~MK in the core active region NOAA~11193, first when it appeared near the central meridian and then again when it re-appeared after a solar…

Solar and Stellar Astrophysics · Physics 2015-06-23 Giulio Del Zanna , Durgesh Tripathi , Helen Mason , Srividya Subramanian , Brendan O'Dwyer

Coronal holes are large-scale structures in the solar atmosphere that feature a reduced temperature and density in comparison to the surrounding quiet Sun and are usually associated with open magnetic fields. We perform a differential…

Solar and Stellar Astrophysics · Physics 2021-03-01 Stephan G. Heinemann , Jonas Saqri , Astrid M. Veronig , Stefan J. Hofmeister , Manuela Temmer

Coronal jets are short-lived eruptive features commonly observed in polar coronal holes and are thought to play a key role in the transfer of mass and energy into the solar corona. We describe unique contemporaneous observations of a…

The Extreme-ultraviolet Variability Experiment (EVE) onboard the Solar Dynamics Observatory (SDO) detects the solar EUV spectra with high temporal cadence and spectral resolution. The wavelength shifts of emission lines provide key…

Solar and Stellar Astrophysics · Physics 2021-04-21 Zhixun Cheng , Yuming Wang , Rui Liu

The goal of this paper is to study the smallest brightening events observed in the EUV quiet Sun. We use commissioning data taken by the EUI instrument onboard the recently launched Solar Orbiter mission. On 2020 May 30, EUI was situated at…

We benchmark new atomic data against a selection of irradiances obtained from medium-resolution quiet Sun spectra in the EUV, from 60 to 1040 \AA. We use as a baseline the irradiances measured during solar minimum on 2008 April 14 by the…

Solar and Stellar Astrophysics · Physics 2019-04-03 G. Del Zanna

New instruments sensitive to chromospheric radiation at X-ray, UV, Visible, IR, and sub-mm wavelengths have become available that significantly enhance our ability to understand the bi-directional flow of energy through the chromosphere. We…

Solar and Stellar Astrophysics · Physics 2022-07-27 Adam R. Kobelski , Lucas A. Tarr , Sarah A. Jaeggli , Nicholas Luber , Harry P. Warren , Sabrina L. Savage

The observations from 1998 April 20 taken with the Coronal Diagnostics Spectrometer CDS on SOHO of a coronal loop on the limb have shown that the plasma was multi-thermal along each line of sight investigated, both before and after…

Astrophysics · Physics 2009-11-13 J. T. Schmelz , P. C. H. Martens

The identification of large numbers of localised transient EUV brightenings, with small spatial scales, in the quiet-Sun corona has been one of the key early results from Solar Orbiter. However, much is still unknown about these events.…

The infrared solar spectrum contains a wealth of physical data about the Sun and is being explored using modern detectors and technology with new ground-based solar telescopes. One such instrument will be the ground-based Cryogenic Near-IR…

Solar and Stellar Astrophysics · Physics 2022-06-22 Aatiya Ali , Alin Paraschiv , Kevin Reardon , Philip Judge

During non-flaring times, the radio flux of the Sun at the wavelength of a few centimeters to several tens of centimeters mostly originates from the thermal bremsstrahlung emission, very similar to the EUV radiation. Owing to such a…

Solar and Stellar Astrophysics · Physics 2020-03-11 Z. F. Li , S. H. Hua , X. Cheng , M. D. Ding

The average Doppler shift shown by spectral lines formed from the chromosphere to the corona reveals important information on the mass and energy balance of the solar atmosphere, providing an important observational constraint to any models…

Solar and Stellar Astrophysics · Physics 2011-09-22 Neda Dadashi , Luca Teriaca , Sami K. Solanki

We present an analysis of EUV and soft X-ray emission detected toward Comet Lovejoy (C/2011 W3) during its post-perihelion traverse of the solar corona on December 16, 2011. Observations were recorded by the Atmospheric Imaging Assembly…

Earth and Planetary Astrophysics · Physics 2015-06-15 Patrick I. McCauley , Steven H. Saar , John C. Raymond , Yuan-Kuen Ko , Pascal Saint-Hilaire

The use of the coronal approximation to model line emission from the solar transition region has led to discrepancies with observations over many years, particularly for Li- and Na-like ions. Studies have shown that a number of atomic…

Solar and Stellar Astrophysics · Physics 2023-05-05 Roger Dufresne , Giulio Del Zanna , Helen Mason

Emerging dimming occurs in isolated solar active regions (ARs) during the early stages of magnetic flux emergence. Observed by the Atmospheric Imaging Assembly, it features a rapid decrease in extreme-ultraviolet (EUV) emission in the 171…

Solar and Stellar Astrophysics · Physics 2021-05-05 Anna V. Payne , Xudong Sun

Context: Hot coronal jets are a basic observed feature of the solar atmosphere whose physical origin is still being actively debated. Aims: We study six recurrent jets occurring in the active region NOAA 12644 on April 04, 2017. They are…

Thermal plasma of solar atmosphere includes a wide range of temperatures. This plasma is often quantified, both in observations and models, by a differential emission measure (DEM). DEM is a distribution of the thermal electron density…

Solar and Stellar Astrophysics · Physics 2021-06-23 Gregory D. Fleishman , Alexey A. Kuznetsov , Enrico Landi

Magnetic fields are the primary driver of the plasma thermodynamics in the upper solar atmosphere, especially in the corona. However, magnetic field measurements in the solar corona are sporadic, thereby limiting us from the complete…

Solar and Stellar Astrophysics · Physics 2024-06-12 Raveena Khan , Sarah E. Gibson , Roberto Casini , K. Nagaraju

Coronal loops form the basic building blocks of the magnetically closed solar corona yet much is still to be determined concerning their possible fine-scale structuring and the rate of heat deposition within them. Using an improved…

Solar and Stellar Astrophysics · Physics 2021-07-07 Thomas Williams , Robert W. Walsh , Stephane Regnier , Craig D. Johnston