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Related papers: Solar Flare Ion Temperatures

200 papers

Solar pores are strongly magnetized regions lacking a photospheric penumbra and characterized by predominantly vertical magnetic fields. We present a multi-line study of flashes in a solar pore using high-resolution observations from the…

Solar and Stellar Astrophysics · Physics 2026-02-11 Sandeep Dubey , Christian Beck , Rahul Yadav , Tobias Felipe , Shibu K Mathew

Flare kernels are compact features located in the solar chromosphere that are the sites of rapid heating and plasma upflow during the rise phase of flares. An example is presented from a M1.1 class flare observed on 2011 February 16 07:44…

Solar and Stellar Astrophysics · Physics 2015-06-12 Peter Young , George Doschek , Harry Warren , Hiro Hara

Aims. The main objective of this article is to provide a simple physical framework with permits a quantitative comparison of measurements of the temperature fluctuations in the ionized interstellar medium with possible mechanisms which can…

Astrophysics · Physics 2007-05-23 C. Giammanco , J. E. Beckman

(Abridged) We use high S/N spectra of 20 HII regions in the giant spiral galaxy M101 to derive electron temperatures for the HII regions and robust metal abundances over radii R = 0.19-1.25 Ro (6-41 kpc). We compare the consistency of…

Astrophysics · Physics 2009-11-07 Robert C. Kennicutt , Fabio Bresolin , Don R. Garnett

This work presents a magnetic reconnection experiment in which the kinetic, magnetic and thermal properties of the plasma each play an important role in the overall energy balance and structure of the generated reconnection layer. Magnetic…

The steep power-law dependence of element abundance enhancements on the mass-to-charge ratios [A/Q] of the ions in impulsive solar energetic-particle (SEP) events causes these enhancements to reflect the temperature-dependent pattern of Q…

Solar and Stellar Astrophysics · Physics 2015-10-05 Donald V. Reames , Edward W. Cliver , Stephen W. Kahler

We present long-slit spectrophotometric observations in the red and near infrared of 12 HII galaxies. The spectral range includes the sulphur lines [SII] at wavelengths 6716, 6731 angstroms and [SIII] at 6312 angstroms and 9069, 9532…

Astrophysics · Physics 2009-11-10 Enrique Perez-Montero , Angeles I. Diaz

Orbits six through nine of the Parker Solar Probe have been studied to show that solar wind core electrons emerged from 15 solar radii with temperatures that were constant to within ~10% although the solar wind speed varied from 300 to 800…

Solar and Stellar Astrophysics · Physics 2022-05-04 F. S. Mozer , S. D. Bale , C. A. Cattell , J. Halekas , I. Y. Vasko , J. L. Verniero , P. J. Kellogg

We perform a high-resolution two-dimensional fully-kinetic numerical simulation of a turbulent plasma system with observation-driven conditions, in order to investigate the interplay between turbulence, magnetic reconnection, and particle…

Heavy (O+) ion energization and field-aligned motion in and near the ionosphere are still not well understood. Based on observations from the CASSIOPE Enhanced Polar Outflow Probe (e-POP) at altitudes between 325 km and 730 km over one…

We study correlations of the temperature ratio (which is an indicator for perpendicular ion heating) and the differential flow of the alpha particles with the power of transverse fluctuations that have wave numbers between 0.01 and 0.1…

Solar and Stellar Astrophysics · Physics 2011-11-14 S. Bourouaine , E. Marsch , F. M. Neubauer

Putative organisms on the Martian surface would be exposed to potentially high doses of ionizing radiation during strong solar X-ray flares. We extrapolate the observed flare frequency-energy release scaling relation to releases much larger…

Astrophysics · Physics 2009-06-08 David S. Smith , John M. Scalo

We present a new diagnostic allowing one to measure the anisotropy of ion temperatures and non-thermal velocities as well as Doppler shifts with respect to the ambient magnetic field. This method provides new results, as well as independent…

Solar and Stellar Astrophysics · Physics 2015-06-12 M. Hahn , D. W. Savin

Spectral line widths are often observed to be larger than can be accounted for by thermal and instrumental broadening alone. This excess broadening is a key observational constraint for both nanoflare and wave dissipation models of coronal…

Solar and Stellar Astrophysics · Physics 2016-03-23 David H. Brooks , Harry P. Warren

Intending to solve the decade old problem of solar opacity, we report substantial photoabsorption uncertainty due to the effect of ion-ion correlations. By performing detailed opacity calculations of the solar mixture, we find that taking…

Solar and Stellar Astrophysics · Physics 2018-03-01 Menahem Krief , Yair Kurzweil , Alexander Feigel , Doron Gazit

Electron bulk heating during magnetic reconnection with symmetric inflow conditions is examined using kinetic particle-in-cell (PIC) simulations. The degree of electron heating is well correlated with the inflowing Alfv\'en speed $c_{Ar}$…

Plasma Physics · Physics 2015-06-23 M. A. Shay , C. C. Haggerty , T. D. Phan , J. F. Drake , P. A. Cassak , P. Wu , M. Oieroset , M. Swisdak , K. Malakit

Particle-in-cell direct simulation Monte Carlo simulations reveal that ion-acoustic instabilities excited in presheaths can cause significant ion heating. Ion-acoustic instabilities are excited by the ion flow toward a sheath when the…

Plasma Physics · Physics 2022-01-05 Lucas Beving , Matthew Hopkins , Scott Baalrud

Solar spectra of ultraviolet bursts and flare ribbons from the Interface Region Imaging Spectrograph (IRIS) have suggested high electron densities of $>10^{12}$ cm$^{-3}$ at transition region temperatures of 0.1 MK, based on large intensity…

Solar and Stellar Astrophysics · Physics 2018-04-25 P. R. Young , F. P. Keenan , R. O. Milligan , H. Peter

The \ion{Fe}{i} lines observed by the Hinode/SOT spectropolarimeter were always seen in absorption, apart from the extreme solar limb. Here we analyse a unique dataset capturing these lines in emission during a solar white-light flare. We…

Solar and Stellar Astrophysics · Physics 2018-12-19 Jan Jurcak , Jana Kasparova , Michal Svanda , Lucia Kleint

Scattering, during interplanetary transport in large, "gradual" solar energetic-particle (SEP) events, can cause element abundance enhancements or suppressions that depend upon the mass-to-charge ratio A/Q of the ions as an increasing…

Solar and Stellar Astrophysics · Physics 2016-01-21 Donald V. Reames