Transition region features observed with Hinode/EIS
arXiv:0706.1856 · doi:10.1093/pasj/59.sp3.S727
Abstract
Two types of active region feature prominent at transition region temperatures are identified in Hinode/EIS data of AR 10938 taken on 2007 January 20. The footpoints of 1 MK TRACE loops are shown to emit strongly in emission lines formed at log T=5.4-5.8, allowing the temperature increase along the footpoints to be clearly seen. A density diagnostic of Mg VII yields the density in the footpoints, with one loop showing a decrease from 3x10^9 cm^-3 at the base to 1.5x10^9 cm^-3 at a projected height of 20 Mm. The second feature is a compact active region transition region brightening which is particularly intense in O V emission (log T=5.4) but also has a signature at temperatures up to log T=6.3. The Mg VII diagnostic gives a density of 4x10^10 cm^-3, and emission lines of Mg VI and Mg VII show line profiles broadened by 50 km/s and wings extending beyond 200 km/s. Continuum emission in the short wavelength band is also found to be enhanced, and is suggested to be free-bound emission from recombination onto He^+.
11 pages, 9 figures, submitted to PASJ Hinode first results issue
References in corpus (1)
Cited by in corpus (32)
- Solar UV and X-Ray Spectral Diagnostics
- EUV emission lines and diagnostics observed with Hinode/EIS
- High precision density measurements in the solar corona: I. Analysis methods and results for Fe XII and Fe XIII
- On active region loops: Hinode/EIS observations
- Solar ultraviolet bursts
- Multiwavelength Observations of Small-Scale Reconnection Events triggered by Magnetic Flux Emergence in the Solar Atmosphere
- Active region transition region loop populations and their relationship to the corona
- Emission Measure Distribution and Heating of Two Active Region Cores
- Velocity measurements for a solar active region fan loop from Hinode/EIS observations
- Hinode/Extreme-Ultraviolet Imaging Spectrometer Observations of the Temperature Structure of the Quiet Corona
- CHIANTI - An atomic database for emission lines. X. Spectral atlas of a cold feature observed with Hinode/EIS
- Different Patterns of Chromospheric Evaporation in a Flaring Region Observed with Hinode/EIS
- EUV spectral line formation and the temperature structure of active region fan loops: observations with Hinode/EIS and SDO/AIA
- Active Region Moss: Basic physical parameters and their temporal variation
- Temporal Variability of Active Region Outflows
- CHIANTI - An atomic database for emission lines. XI. EUV emission lines of Fe VII, Fe VIII and Fe IX observed by Hinode/EIS
- New EUV Fe IX emission line identifications from Hinode/EIS
- Evidence of Impulsive Heating in Active Region Core Loops
- A closer look at a coronal loop rooted in a sunspot umbra
- Observations of EUV and Soft X-ray Recurring Jets in an Active Region
- Spectroscopic Observations of a Coronal Loop: Basic Physical Plasma Parameters Along the Full Loop Length
- Underflight calibration of SOHO/CDS and Hinode/EIS with EUNIS-07
- Evolution of microflares associated with bright points in coronal holes and in quiet regions
- EUV lines observed with EIS/Hinode in a solar prominence
- Discovery of Molecular Loop 3 in the Galactic Center: Evidence for a Positive-Velocity Magnetically Floated Loop towards
- On the nature of spectral line broadening in solar coronal dimmings
- Determining Energy Balance in the Flaring Chromosphere from Oxygen V Line Ratios
- Formation Heights of Extreme Ultraviolet Lines in an Active Region Derived by Correlation of Doppler Velocity and Magnetic Field
- Direct Observations of Plasma Upflows and Condensation in a Catastrophically Cooling Solar Transition Region Loop
- Comparative Analysis of a Transition Region Bright Point with a Blinker and Coronal Bright Point Using Multiple EIS Emission Lines
- Interaction and Eruption of Two Filaments Observed by Hinode, SOHO, and STEREO
- Signatures of Helium continuum in cool flare loops observed by SDO/AIA