Results 41 to 50 of about 2,361 (168)

A burst model for line emission in the solar atmosphere. II - Coronal extreme ultraviolet lines

The Astrophysical Journal, 1992
We review the spectroscopic evidence for explosive events, hereafter referred to as bursts, occurring in solar coronal plasmas. Problems in the interpretation of extreme ultraviolet spectra from Mg-like ions, particularly Fe XV in solar flares can be obviated to certain extent if these ions are produced in an ionizing plasma, with the 3s3p 3 P levels ...
U. Feldman, J. M. Laming, P. Mandelbaum, W. H. Goldstein, A. Osterheld   +4 more
openaire   +1 more source

Emission lines of Fe xv in spectra obtained with the Solar Extreme-Ultraviolet Research Telescope and Spectrograph [PDF]

Monthly Notices of the Royal Astronomical Society, 2005
Recent R-matrix calculations of electron impact excitation rates in Mg-like Fe XV are used to derive theoretical emission-line ratios involving transitions in the 243‐418 A wavelength range. A comparison of these with a data set of solar active region, subflare and off-limb spectra, obtained during rocket flights by the Solar Extreme-Ultraviolet ...
Keenan, Francis, Aggarwal, Kanti, Milligan, Ryan, Ryans, Robert, Bloomfield, Shaun, Srigengan, Viji, O'Mullane, M.G., Lawson, K.D., Msezane, A.Z., Brosius, J.W., Davila, J.M., Thomas, R.J.   +11 more
openaire   +2 more sources

Enhanced Peak and Extended Cooling of the Extreme-ultraviolet Late Phase in a Confined Solar Flare

The Astrophysical Journal
We present observations and analysis of an X1.8 noneruptive solar flare on 2012 October 23, which is characterized by an extremely large late-phase peak seen in the warm coronal extreme-ultraviolet (EUV) emissions (∼3 MK), with the peak intensity over 1 ...
Shihan Li, Yu Dai, Mingde Ding, Zhen Li, Jinhan Guo, Hao Wu   +5 more
doaj   +1 more source

High precision, high time-cadence measurements of the Mg II index of solar activity by the GOES-R Extreme Ultraviolet Irradiance Sensor 1: EUVS-C design and preflight calibration

Journal of Space Weather and Space Climate
EUVS-C is one component of the Extreme Ultraviolet Irradiance Sensor (EUVS) instrument. EUVS, together with the X-Ray Sensor (XRS), comprise the Extreme Ultraviolet and X-ray Irradiances Sensors (EXIS) investigation aboard the GOES-R satellite series ...
McClintock William E., Snow Martin, Crotser David, Eparvier Francis G.   +3 more
doaj   +1 more source

Multi-spacecraft Observations of the 2022 March 25 CME and EUV Wave: An Analysis of Their Propagation and Interrelation

The Astrophysical Journal, 2023
This paper reports on a well-defined EUV wave associated with a coronal mass ejection (CME) observed on 2022 March 25. The CME was observed by Solar Orbiter (SolO) during its first close perihelion (0.32 au) and by several other spacecraft from different
Alessandro Liberatore, Paulett C. Liewer, Angelos Vourlidas, Carlos R. Braga, Marco Velli, Olga Panasenco, Daniele Telloni, Salvatore Mancuso   +7 more
doaj   +1 more source

Fe xiii emission lines in active region spectra obtained with the Solar Extreme-Ultraviolet Research Telescope and Spectrograph [PDF]

Monthly Notices of the Royal Astronomical Society, 2007
Abstract Recent fully relativistic calculations of radiative rates and electron impact excitation cross-sections for Fe xiii are used to generate emission-line ratios involving 3s23p2–3s3p3 and 3s23p2–3s23p3d transitions in the 170–225 and 235–450 Å wavelength ranges covered by the Solar Extreme-Ultraviolet Research Telescope and ...
Keenan, F. P., Jess, D. B., Aggarwal, K. M., Thomas, R. J., Brosius, J. W., Davila, J. M.   +5 more
openaire   +4 more sources

Time-dependent Hinode/EIS Atlas of a Coronal Mass Ejection Containing Cool Material

The Astrophysical Journal
We report the first time-dependent spectral atlas of a coronal mass ejection (CME) observed by the Hinode/Extreme Ultraviolet Imaging Spectrometer (EIS).
E. M. Wraback, E. Landi, W. B. Manchester   +2 more
doaj   +1 more source

Data-constrained 3D Modeling of a Solar Flare Evolution: Acceleration, Transport, Heating, and Energy Budget

The Astrophysical Journal, 2023
Solar flares are driven by the release of free magnetic energy and its conversion to other forms of energy—kinetic, thermal, and nonthermal. Quantification of partitions between these energy components and their evolution is needed to understand the ...
Gregory D. Fleishman, Gelu M. Nita, Galina G. Motorina   +2 more
doaj   +1 more source

Emission lines of Fe x in active region spectra obtained with the Solar Extreme-ultraviolet Research Telescope and Spectrograph [PDF]

Monthly Notices of the Royal Astronomical Society, 2008
Fully relativistic calculations of radiative rates and electron impact excitation cross sections for Fe X are used to derive theoretical emission-line ratios involving transitions in the 174-366 A wavelength range. A comparison of these with solar active region observations obtained during the 1989 and 1995 flights of the Solar Extreme-ultraviolet ...
Keenan, F. P., Jess, D. B., Aggarwal, K. M., Thomas, R. J., Brosius, J. W., Davila, J. M.   +5 more
openaire   +4 more sources

Fe xviii and Fe xx Forbidden Lines Observed by Solar Orbiter/SPICE

The Astrophysical Journal
The first simultaneous observations of the Fe xviii 974.86 Å and Fe xx 721.56 Å forbidden lines from the Spectral Imaging of the Coronal Environment (SPICE) spectrograph on Solar Orbiter are presented.
Peter R. Young, Andrew R. Inglis, Graham S. Kerr, Therese A. Kucera, Daniel F. Ryan   +4 more
doaj   +1 more source