New views on the emission and structure of the solar transition region

Abstract

The Sun is the only star that we can spatially resolve and it can be regarded as a fundamental plasma laboratory of astrophysics. The solar transition region (TR), the layer between the solar chromosphere and corona, plays an important role in solar wind origin and coronal heating. Recent high-resolution observations made by SOHO, TRACE, and Hinode indicate that the TR is highly nonuniform and magnetically structured. Through a combination of spectroscopic observations and magnetic field extrapolations, the TR magnetic structures and plasma properties have been found to be different in coronal holes and in the quiet Sun. In active regions, the TR density and temperature structures also differ in sunspots and the surrounding plage regions. Although the TR is believed to be a dynamic layer, quasi-steady flows lasting from several hours to several days are often present in the quiet Sun, coronal holes, and active regions, indicating some kind of plasma circulation/convection in the TR and corona. The emission of hydrogen Lyman lines, which originates from the lower TR, has also been intensively investigated in the recent past. Observations show clearly that the flows and dynamics in the middle and upper TR can greatly modify the Lyman line profiles.

This paper has been withdrawn by the authors. This is a repetition of another record in ADS: New Astronomy Reviews, Volume 54, Issue 1-2, p. 13-30

References in corpus (26)

• Observing the Roots of Solar Coronal Heating - in the Chromosphere
• Ubiquitous High Speed Transition Region and Coronal Upflows in the Quiet Sun
• Observing Episodic Coronal Heating Events Rooted in Chromospheric Activity
• Similarities and Differences between Coronal Holes and the Quiet Sun: Are Loop Statistics the Key?
• Observational Test of Coronal Magnetic Field Models I. Comparison with Potential Field Model
• The nascent fast solar wind observed by EIS onboard Hinode
• Cool and hot components of a coronal bright point
• Links between magnetic fields and plasma flows in a coronal hole
• Catastrophic eruption of magnetic flux rope in the corona and solar wind with and without magnetic reconnection
• Upflows in funnel-like legs of coronal magnetic loops
• The Ly-alpha profile and center-to-limb variation of the quiet Sun
• Solar transition region above sunspots
• Characteristic Dependence of Umbral Dots on their Magnetic Structure
• Sizes of transition-region structures in coronal holes and in the quiet Sun
• Hydrogen Lyman-alpha and Lyman-beta spectral radiance profiles in the quiet Sun
• Signature of mass supply to quiet coronal loops
• Two-Current-Sheet Reconnection Model of Interdependent Flare and Coronal Mass Ejection
• Statistics of Flares Sweeping across Sunspots
• The Ly<alpha> and Ly<beta> profiles in solar prominences and prominence fine structure
• Emission heights of coronal bright points on Fe XII radiance map
• On The Mass and Energy Loading of EUV Brightpoints
• Hydrogen Lyman-alpha and Lyman-beta radiances and profiles in polar coronal holes
• The redshifted network contrast of transition region emission
• SUMER observations of the inverse Evershed effect in the transition region above a sunspot
• The SUMER Lyman-alpha line profile in quiescent prominences
• Radiance and Doppler shift distributions across the network of the quiet Sun

Cited by in corpus (5)

• Observation of High-speed Outflow on Plume-like Structures of the Quiet Sun and Coronal Holes with SDO/AIA
• Diagnostics of the Coronal Hole and the adjacent Quiet Sun by The Hinode/EUV Imaging Spectrometer (EIS)
• Probing the quiet solar atmosphere from the photosphere to the corona
• The Evolution of High Temperature Plasma in Magnetar Magnetospheres and its Implications for Giant Flares
• Spectroscopic study of solar transition region oscillations in the quiet-Sun observed by IRIS using Si IV spectral line