Is the High-Resolution Coronal Imager Resolving Coronal Strands? Results from AR 12712

Abstract

Following the success of the first mission, the High-Resolution Coronal Imager (Hi-C) was launched for a third time (Hi-C 2.1) on 29th May 2018 from the White Sands Missile Range, NM, USA. On this occasion, 329 seconds of 17.2 nm data of target active region AR 12712 was captured with a cadence of ~4s, and a plate scale of 0.129''/pixel. Using data captured by Hi-C 2.1 and co-aligned observations from SDO/AIA 17.1 nm we investigate the widths of 49 coronal strands. We search for evidence of substructure within the strands that is not detected by AIA, and further consider whether these strands are fully resolved by Hi-C 2.1. With the aid of Multi-Scale Gaussian Normalization (MGN), strands from a region of low-emission that can only be visualized against the contrast of the darker, underlying moss are studied. A comparison is made between these low-emission strands with those from regions of higher emission within the target active region. It is found that Hi-C 2.1 can resolve individual strands as small as ~202km, though more typical strands widths seen are ~513km. For coronal strands within the region of low-emission, the most likely width is significantly narrower than the high-emission strands at ~388km. This places the low-emission coronal strands beneath the resolving capabilities of SDO/AIA, highlighting the need of a permanent solar observatory with the resolving power of Hi-C.

19 pages, 10 images, 3 tables

References in corpus (27)

• The Interface Region Imaging Spectrograph (IRIS)
• Multi-scale Gaussian normalization for solar image processing
• The influence of numerical resolution on coronal density in hydrodynamic models of impulsive heating
• Structure of solar coronal loops: from miniature to large-scale
• Observing coronal nanoflares in active region moss
• On active region loops: Hinode/EIS observations
• Constraints on the Heating of High Temperature Active Region Loops: Observations from Hinode and SDO
• High Spatial Resolution Observations of Loops in the Solar Corona
• Coronal Loops: Observations and Modeling of Confined Plasma
• Solar Coronal Loops Associated with Small-scale Mixed Polarity Surface Magnetic Fields
• The Width Distribution of Loops and Strands in the Solar Corona -- Are we Hitting Rock Bottom ?
• The High-Resolution Coronal Imager, Flight 2.1
• Evidence for Steady Heating: Observations of an Active Region Core with Hinode and TRACE
• Anti-parallel EUV flows observed along active region filament threads with Hi-C
• Measuring the magnetic field of a trans-equatorial loop system using coronal seismology
• Trigger Mechanism of Solar Subflares in a Braided Coronal Magnetic Structure
• Force-free field modeling of twist and braiding-induced magnetic energy in an active-region corona
• Are Coronal Loops Isothermal or Multithermal? Yes!
• Data-driven model of the solar corona above an active region
• Plasma evolution within an erupting coronal cavity
• Properties and Modeling of Unresolved Fine Structure Loops Observed in the Solar Transition Region by IRIS
• Miniature loops in the solar corona
• Hydrodynamic Simulation of a nano-flare heated multi-strand solar atmospheric loop
• Automated detection of coronal mass ejections in three-dimensions using multi-viewpoint observations
• Flows and Waves in Braided Solar Coronal Magnetic Structures
• Global Energetics of Solar Flares. IX. Refined Magnetic Modeling
• EUV Observational consequences of the spatial localisation of nanoflare heating within a multi-stranded atmospheric loop

Cited by in corpus (23)

• The Solar Orbiter mission -- Science overview
• A solar coronal loop in a box: Energy generation and heating
• Weak damping of propagating MHD kink waves in the quiescent corona
• Stirring the Base of the Solar Wind: On Heat Transfer and Vortex Formation
• EUV fine structure and variability associated with coronal rain revealed by Solar Orbiter/EUI HRIEUV and SPICE
• Evidence for and Analysis of Multiple Hidden Coronal Strands in Cross-Sectional Emission Profiles: Further Results from NASA's High-resolution Solar Coronal Imager
• A model for heating the super-hot corona in solar active regions
• Effect of Coronal Loop Structure on Wave Heating by Phase Mixing
• Hi-C 2.1 Observations of Reconnection Nanojets
• The fine-scale structure of polar coronal holes
• Excitation and evolution of coronal oscillations in self-consistent 3D radiative MHD simulations of the solar atmosphere
• The dynamics and observability of circularly polarized kink waves
• Alfvén Waves in Solar Flares
• Nanoflare Diagnostics from Magnetohydrodynamic Heating Profiles
• Evolution Of Downflows In The Transition Region Above A Sunspot Over Short Time-Scales
• Multi-Stranded Coronal Loops: Quantifying Strand Number and Heating Frequency from Simulated Solar Dynamics Observatory (SDO) Atmospheric Imaging Assembly (AIA) Observations
• Diffuse solar coronal features and their spicular footpoints
• The need for new techniques to identify the high-frequency MHD waves of an oscillating coronal loop
• Can we rely on EUV emission to identify coronal waveguides?
• Case study on the identification and classification of small-scale flow patterns in flaring active region
• Inevitable consequences of ion-neutral damping of intermediate MHD waves in Sun-like stars
• Categorization model of moving small-scale intensity enhancements in solar active regions
• The cross-sectional shape and height expansion of coronal loops: High-resolution Coronal Imager (Hi-C) analysis of AR 12712