We have used an electron beam ion trap to measure electron-density-diagnostic line-intensity ratios for extreme ultraviolet lines from F XII, XIII, and XIV at wavelengths of 185-205 255-276 Angstroms. These ratios can be used as density diagnostics for astrophysical spectra and are especially relevant to solar physics. We found that density diagnostics using the Fe XIII 196.53/202.04 and the Fe XIV 264.79/274.21 and 270.52A/274.21 line ratios are reliable using the atomic data calculated with the Flexible Atomic Code. On the other hand, we found a large discrepancy between the FAC theory and experiment for the commonly used Fe XII (186.85 + 186.88)/195.12 line ratio. These FAC theory calculations give similar results to the data tabulated in CHIANTI, which are commonly used to analyze solar observations. Our results suggest that the discrepancies seen between solar coronal density measurements using the Fe XII (186.85 + 186.88)/195.12 and Fe XIII 196.54/202.04 line ratios are likely due to issues with the atomic calculations for Fe XII.
Using the multiconfiguration Dirac-Hartree-Fock and the relativistic configuration interaction methods, a consistent set of transition energies and radiative transition data for the lowest 546 (623, 701, 745) states of the $3p^4 3d$, $3s 3p^2 3d^2$, $3s 3p^3 4p$, $3s 3p^4$, $3s^2 3d^3$, $3s^2 3p^2 3d$, $3s^2 3p^2 4d$, $3s^2 3p^2 4s$, $3p^3 3d^2$, $3p^5$, $3s 3p 3d^3$, $3s 3p^3 3d$, $3s 3p^3 4s$, $3s^2 3p 3d^2$, %$3s^2 3p^2 4f$, $3s^2 3p^2 4p$, $3s^2 3p^3$ configurations in Mn~XI (Fe~XII, Co~XIII, Ni~XIV) is provided. The comparison between calculated excitation energies for the $n=4$ states an…
A collection of the best solar and laboratory spectra in the soft X-rays is used here to perform a preliminary benchmark in this wavelength region, by comparing observed vs. predicted wavelengths and calibrated solar irradiances. The benchmark focuses on the Fe IX - Fe XIV ions,for which we have recently calculated the relevant atomic data, however a few other ions have also been benchmarked. The iron ions are dominating the soft X-rays, however a large fraction of the strongest soft X-ray lines due to n=4 -> n=3 transitions were previously unidentified. The strongest transitions are all ident…
This report summarizes laboratory measurements of atomic wavelengths, energy levels, hyperfine and isotope structure, energy level lifetimes, and oscillator strengths. Theoretical calculations of lifetimes and oscillator strengths are also included. The bibliography is limited to species of astrophysical interest. Compilations of atomic data and internet databases are also included. Papers are listed in the bibliography in alphabetical order, with a reference number in the text.
This paper presents a detailed study of excess line broadening in EUV emission lines during the impulsive phase of a C-class solar flare. In this work, which utilizes data from the EUV Imaging Spectrometer (EIS) onboard Hinode, the broadened line profiles were observed to be co-spatial with the two HXR footpoints as observed by RHESSI. By plotting the derived nonthermal velocity for each pixel within the Fe XV and Fe XVI rasters against its corresponding Doppler velocity a strong correlation (|r| > 0.59) was found between the two parameters for one of the footpoints. This suggested that the ex…
We have measured electron-ion recombination for Fe XII forming Fe XI using a merged beams configuration at the heavy-ion storage ring TSR located at the Max Planck Institute for Nuclear Physics in Heidelberg, Germany. The measured merged beams recombination rate coefficient (MBRRC) for collision energies from 0 to 1500 eV is presented. This work uses a new method for determining the absolute MBRRC based on a comparison of the ion beam decay rate with and without the electron beam on. For energies below 75 eV, the spectrum is dominated by dielectronic recombination (DR) resonances associated wi…
We present a study of the physical plasma parameters such as electron temperature, electron density, column depth and filling factors in the moss regions and their variability over a short (an hour) and a long period (5 consecutive days) of time. Primarily, we have analyzed the spectroscopic observations recorded by the Extreme-ultraviolet Imaging Spectrometer (EIS) aboard Hinode. In addition we have used supplementary observations taken from TRACE and the X-Ray Telescope (XRT). We find that the moss emission is strongest in the Fe xii and Fe xiii lines. Based on analyses using line ratios and…
The aim of this paper is to try to explain the physical origin of the non-thermal electron distribution that is able to form the enhanced intensities of satellite lines in the X-ray line spectra observed during the impulsive phases of some solar flares. Synthetic X-ray line spectra of the distributions composed of the distribution of shock reflected electrons and the background Maxwellian distribution are calculated in the approximation of non-Maxwellian ionization, recombination, excitation and de-excitation rates. The distribution of shock reflected electrons is determined analytically. We f…
We present an investigation of a coronal cavity observed above the western limb in the coronal red line Fe X 6374 Å using a telescope of Peking University and in the green line Fe XIV 5303 Å using a telescope of Yunnan Observatories, Chinese Academy of Sciences during the total solar eclipse on 2017 August 21. A series of magnetic field models are constructed based on the magnetograms taken by the Helioseismic and Magnetic Imager onboard the Solar Dynamics Observatory (SDO) one week before the eclipse. The model field lines are then compared with coronal structures seen in images taken by the …
We present the first Hinode/EIS observations of 5 min quasi-periodic oscillations detected in a transition-region line (He II) and five coronal lines (Fe X, Fe XII, Fe XIII, Fe XIV, and Fe XV) at the footpoint of a coronal loop. The oscillations exist throughout the whole observation, characterized by a series of wave packets with nearly constant period, typically persisting for 4-6 cycles with a lifetime of 20-30 min. There is an approximate in-phase relation between Doppler shift and intensity oscillations. This provides evidence for slow magnetoacoustic waves propagating upwards from the tr…
Comparing First Ionisation Potential bias diagnostics in the solar atmosphere
Dublin City University（都柏林城市大学）；Dublin Institute for Advanced Studies（都柏林高等研究院）；European Space Agency (ESA), European Space Research and Technology Centre (ESTEC)（欧洲空间局（ESA），欧洲空间研究与技术中心（ESTEC））
Ejecta clumps revealed by study of reverse-shocked ejecta through MUSE integral field spectroscopy of SNR 0509-67.5
The University of New South Wales（新南威尔士大学）；Australian National University（澳大利亚国立大学）；Naval Research Laboratory（海军研究实验室）；The University of Manitoba（曼尼托巴大学）；RIKEN Center for Interdisciplinary Theoretical and Mathematical Sciences (iTHEMS)（理化学研究所跨学科理论与数学科学中心（iTHEMS））
Spectroscopic Observations of the Solar Corona during the 2017 August 21 Total Solar Eclipse: Comparison of Spectral Line Widths and Doppler Shifts Between Open and Closed Magnetic Structures
(Abridged) The results of a Chandra X-ray Observatory High-Energy Transmission Grating (HETG) observation of the nova-like cataclysmic binary AE Aqr are described. First, the X-ray spectrum is that of an optically thin multi-temperature thermal plasma; the X-ray emission lines are broad, with widths that increase with the line energy, from sigma~1 eV for O VIII to sigma~5.5 eV for Si XIV; the X-ray spectrum is reasonably well fit by a plasma model with a Gaussian emission measure distribution that peaks at log T(K)=7.16, has a width sigma=0.48, an Fe abundance equal to 0.44 times solar, and ot…
A preliminary assessment of the in-flight radiometric calibration of the Hinode EUV Imaging Spectrometer (EIS) is presented. This is done with the line ratio technique applied to a wide range of observations of the quiet Sun, active regions and flares from 2006 until 2012. The best diagnostic lines and the relevant atomic data are discussed in detail. Radiances over the quiet Sun are also considered, with comparisons with previous measurements. Some departures in the shapes of the ground calibration responsivities are found at the start of the mission. These shapes do not change significantly …
Daily differential emission measure (DEM) distributions of the solar corona are derived from spectra obtained by the Extreme-ultraviolet Variability Experiment (EVE) over a 4-year period starting in 2010 near solar minimum and continuing through the maximum of solar cycle 24. The DEMs are calculated using six strong emission features dominated by Fe lines of charge states VIII, IX, XI, XII, XIV, and XVI that sample the non-flaring coronal temperature range 0.3--5 MK. A proxy for the non-XVIII emission in the wavelength band around the 93.9 Å line is demonstrated. There is little variability in…
We present coordinated coronal observations of the August 21, 2017 total solar eclipse with the Airborne Infrared Spectrometer (AIR-Spec) and the Extreme-ultraviolet Imaging Spectrometer (EIS). These instruments provide an unprecedented view of the solar corona in two disparate wavelength regimes, the near to mid infrared (IR) and the extreme ultraviolet (EUV), opening new pathways for characterizing the complex coronal plasma environment. During totality, AIR-Spec sampled coronal IR spectra near the equatorial west limb, detecting strong sources of Mg VIII, S XI, Si IX, and Si X in two passba…
We present some new accurate CCD photometry analysis of the white light solar corona at the time of the last 20 March 2015 total eclipse (airborne observations on a Falcon 7X and at ground-based Svalbard). We measured coronal brightness profiles taken along radial directions from 1.001 to 3 solar radii in the northern, southern and equatorial regions, after removing the F corona and the sky background. These studies allow to evaluate the density gradients, structures and temperature heterogeneity, by considering the Thomson scattering in white light of the K corona and also emissions of the EU…
