Spectroscopic Observations of a Coronal Loop: Basic Physical Plasma Parameters Along the Full Loop Length

Abstract

Coronal loops are the basic structures of the solar transition region and corona. The understanding of physical mechanism behind the loop heating, plasma flows, and filling are still considered a major challenge in the solar physics. The mechanism(s) should be able to supply mass to the corona from the chromosphere and able to heat the plasma over 1 MK within the small distance of few hundred km from the chromosphere to the corona. This problem makes coronal loops an interesting target for detailed study. In this study, we focus on spectroscopic observations of a coronal loop, observed in its full length, in various spectral lines as recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) on-board Hinode. We derive physical plasma parameters such as electron density, temperature, pressure, column depth, and filling factors along the loop length from one foot-point to the another. The obtained parameters are used to infer whether the observed coronal loop is over-dense or under-dense with respect to gravitational stratification of the solar atmosphere. These new measurements of physical plasma parameters, from one foot-point to another, provide important constraints on the modeling of the mass and energy balance in the coronal loops.

accepted for publication in ApJ

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• Fan Loops Observed by IRIS, EIS and AIA
• The First Flight of the Marshall Grazing Incidence X-ray Spectrometer (MaGIXS)
• Spectroscopic evidence of Alfvén wave damping in the off-limb solar corona
• Exploring the damping of Alfvén waves along a long off-limb coronal loop, up to 1.4 R${}_{\odot }$
• Magnetic filed dynamics and varying plasma emission in large coronal loops
• Electron Densities in the Solar Corona Measured Simultaneously in the Extreme-Ultraviolet and Infra-Red
• On the Impulsive Heating of Quiet Solar Corona
• Transient Formation of Loops in the Core of an Active Region
• Non-equilibrium ionization by a periodic electron beam. I. Synthetic coronal spectra and implications for interpretation of observations
• On Doppler shift and its Center-to-Limb Variation in Active Regions in the Transition Region
• Center to limb variation of transition region Doppler shift in active regions
• How transverse MHD wave-driven turbulence influences the density filling factor in the solar corona?
• Multiwavelength Study of on-disk Coronal Hole Jets with IRIS and SDO observations
• Active region upflows in various coronal structures and their coupling to the lower atmosphere
• Understanding the magnetic field and plasma-$\beta$ along umbral fan loops traced using 3-min slow waves