The Unresolved Fine Structure Resolved - IRIS observations of the Solar Transition Region

Abstract

The heating of the outer solar atmospheric layers, i.e., the transition region and corona, to high temperatures is a long standing problem in solar (and stellar) physics. Solutions have been hampered by an incomplete understanding of the magnetically controlled structure of these regions. The high spatial and temporal resolution observations with the Interface Region Imaging Spectrograph (IRIS) at the solar limb reveal a plethora of short, low lying loops or loop segments at transition-region temperatures that vary rapidly, on the timescales of minutes. We argue that the existence of these loops solves a long standing observational mystery. At the same time, based on comparison with numerical models, this detection sheds light on a critical piece of the coronal heating puzzle.

Published in Science on October 17 and can be found on: http://www.sciencemag.org/content/346/6207/1255757.full?sid=23ef14f7-7090-4270-8eb2-35af3def0fa6 17 pages, 5 figures. Movies are available at http://folk.uio.no/viggoh/download/science_movies/

References in corpus (10)

• The Interface Region Imaging Spectrograph (IRIS)
• On Solving the Coronal Heating Problem
• The stellar atmosphere simulation code Bifrost
• Approximations for radiative cooling and heating in the solar chromosphere
• On red shifs in the transition region and corona
• Low-lying magnetic loops in the solar internetwork
• Twisted flux tube emergence from the convection zone to the corona II: Later states
• Forward modeling of emission in SDO/AIA passbands from dynamic 3D simulations
• On the magnetic structure of the solar transition region
• Search for photospheric footpoints of quiet Sun transition region loops

Cited by in corpus (56)

• The FIP and Inverse FIP Effects in Solar and Stellar Coronae
• Solar UV and X-Ray Spectral Diagnostics
• A publicly available simulation of an enhanced network region of the Sun
• Extreme UV quiet Sun brightenings observed by Solar Orbiter/EUI
• On the prevalence of small-scale twist in the solar chromosphere and transition region
• Solar science with the Atacama Large Millimeter/submillimeter Array - A new view of our Sun
• Recent advances in coronal heating
• Are IRIS bombs connected to Ellerman bombs?
• Critical Science Plan for the Daniel K. Inouye Solar Telescope (DKIST)
• The Multi-slit Approach to Coronal Spectroscopy with the Multi-slit Solar Explorer (MUSE)
• Non-Equilibrium Processes in the Solar Corona, Transition Region, Flares, and Solar Wind \textit{(Invited Review)}
• Discovery of Scattering Polarization in the Hydrogen Lyman-$\alpha$ Line of the Solar Disk Radiation
• Ion-neutral interactions and non-equilibrium ionization in the solar chromosphere
• Element abundance ratios in the quiet Sun transition region
• Non-Maxwellian analysis of the transition-region line profiles observed by the Interface Region Imaging Spectrograph
• Emergence of granular-sized magnetic bubbles through the solar atmosphere. II. Non-LTE chromospheric diagnostics and inversions
• Stereoscopy of extreme UV quiet Sun brightenings observed by Solar Orbiter/EUI
• Statistical study of network jets observed in the solar transition region: A comparison between coronal holes and quiet sun regions
• Observational Evidence of Magnetic Reconnection for Brightenings and Transition Region Arcades in IRIS observations
• The Role of Partial Ionization Effects in the Chromosphere
• Spicules and downflows in the solar chromosphere
• Time Dependent Non-Equilibrium Ionization of Transition Region Lines Observed with IRIS
• Transition Region Abundance Measurements During Impulsive Heating Events
• Measuring the magnetic origins of solar flares, CMEs and Space Weather
• Properties and Modeling of Unresolved Fine Structure Loops Observed in the Solar Transition Region by IRIS
• A Steady-state Supersonic Downflow in the Transition Region above a Sunspot Umbra
• Temperature of Solar Orbiter/EUI quiet Sun small scale brightenings: evidence for a cooler component
• Resonant absorption in expanding coronal magnetic flux tubes with uniform density
• Miniature loops in the solar corona
• IRIS observations of the low-atmosphere counterparts of active region outflows
• Spectroscopic evidence of cool plasma in quiet Sun HRIEUV small scale brightenings
• Chromospheric counterparts of solar transition region unresolved fine structure loops
• Plasma flows in the cool loop systems
• Magnetic connections across the chromosphere-corona transition region
• Formation and Evolution of Coherent Structures in 3D Strongly Turbulent Magnetized Plasmas
• Power-law energy distributions of small-scale impulsive events on the active Sun: Results from IRIS
• Small-scale loops heated to transition region temperatures and their chromospheric signatures in the simulated solar atmosphere
• The dynamic chromosphere: pushing the boundaries of observations and models
• Quantifying the Influence of Key Physical Processes on the Formation of Emission Lines Observed by IRIS: I. Non-Equilibrium Ionization and Density-Dependent Rates
• Mechanism for flow generation/acceleration in dense degenerate stellar atmospheres
• Spectroscopic and imaging observations of transient hot and cool loops by IRIS and SDO
• Non-equilibrium ionization by a periodic electron beam II. Synthetic Si IV and O IV transition region spectra
• Temperature inversion in a gravitationally bound plasma: Case of the solar corona
• The formation and heating of chromospheric fibrils in a radiation-MHD simulation
• What Is the Source of Quiet Sun Transition Region Emission?
• Probing the quiet solar atmosphere from the photosphere to the corona
• Beyond small-scale transients: a closer look at the diffuse quiet solar corona
• Temperature inversion in a confined plasma atmosphere: coarse-grained effect of temperature fluctuations at its base
• The nature of small scale EUV solar brightenings investigated as impulsive heating of short loops in 1D hydrododynamics simulations
• Dynamics of Explosive Events by Interface Region Imaging Spectrograph
• Modelling solar low-lying cool loops with optically thick radiative losses
• The Transition Region of Solar Flare Loops
• Kinetic collisionless model of the solar transition region and corona with spatially intermittent heating
• A new view of the solar interface region from the Interface Region Imaging Spectrograph (IRIS)
• Solar Atmospheric Magnetic Energy Coupling: Broad Plasma Conditions and Spectrum Regimes
• Inevitable consequences of ion-neutral damping of intermediate MHD waves in Sun-like stars