Beyond small-scale transients: a closer look at the diffuse quiet solar corona
arXiv:2308.01640 · doi:10.1051/0004-6361/202345892
Abstract
Within the quiet Sun corona imaged at 1 MK, much of the field of view consists of diffuse emission that appears to lack the spatial structuring that is so evident in coronal loops or bright points. We seek to determine if these diffuse regions are categorically different in terms of their intensity fluctuations and spatial configuration from the more well-studied dynamic coronal features. We analyze a time series of observations from Solar Orbiter's High Resolution Imager in the Extreme Ultraviolet to quantify the characterization of the diffuse corona at high spatial and temporal resolutions. We then compare this to the dynamic features within the field of view, mainly a coronal bright point. We find that the diffuse corona lacks visible structuring, such as small embedded loops, and that this is persistent over the 25 min duration of the observation. The intensity fluctuations of the diffuse corona, which are within +/-5%, are significantly smaller in comparison to the coronal bright point. Yet, the total intensity observed in the diffuse corona is of the same order as the bright point. It seems inconsistent with our data that the diffuse corona is a composition of small loops or jets or that it is driven by discrete small heating events that follow a power-law-like distribution. We speculate that small-scale processes like MHD turbulence might be energizing the diffuse regions, but at this point we cannot offer a conclusive explanation for the nature of this feature.
arXiv commentAccepted for publication in A&A. 10 pages, 8 figures
References in corpus (31)
- The Solar Orbiter mission -- Science overview
- On Solving the Coronal Heating Problem
- A Tale Of Two Spicules: The Impact of Spicules on the Magnetic Chromosphere
- Prevalence of Small-scale Jets from the Networks of the Solar Transition Region and Chromosphere
- Coronal heating by MHD waves
- The Polarimetric and Helioseismic Imager on Solar Orbiter
- Solar fine-scale structures. I. Spicules and other small-scale, jet-like events at the chromospheric level: observations and physical parameters
- Generation of Solar Spicules and Subsequent Atmospheric Heating
- An Interface Region Imaging Spectrograph first view on Solar Spicules
- Structure of solar coronal loops: from miniature to large-scale
- The Unresolved Fine Structure Resolved - IRIS observations of the Solar Transition Region
- Coupling from the photosphere to the chromosphere and the corona
- Patterns of Nanoflare Storm Heating Exhibited by an Active Region Observed with SDO/AIA
- Solar coronal heating from small-scale magnetic braids
- Magnetic loops in the quiet Sun
- Impact of Type II Spicules in the Corona: Simulations and Synthetic Observables
- Quiet Sun Hα Transients and Corresponding Small-Scale Transition Region and Coronal Heating
- Extreme-ultraviolet bursts and nanoflares in the quiet-Sun transition region and corona
- A nanoflare model of quiet Sun EUV emission
- Energetic characterisation and statistics of solar coronal brightenings
- Capturing transient plasma flows and jets in the solar corona
- Multi-Wavelength Observations of the Spatio-Temporal Evolution of Solar Flares with AIA/SDO: II. Hydrodynamic Scaling Laws and Thermal Energies
- Rotating Network Jets in the quiet Sun as Observed by IRIS
- Propagating brightenings in small loop-like structures in the quiet Sun corona: Observations from Solar Orbiter/EUI
- First ALMA Observation of a Solar Plasmoid Ejection from an X-ray Bright Point
- Miniature loops in the solar corona
- First Spectral Analysis of a Solar Plasma Eruption Using ALMA
- Evidence of multithermal nature of spicular downflows. Impact on solar atmospheric heating
- Signatures of dynamic fibrils at the coronal base: Observations from Solar Orbiter/EUI
- Spectroscopic observation of a transition region network jet
- Diffuse solar coronal features and their spicular footpoints