Related papers: Electron energy partition across interplanetary sh…
The degree of deviation from the thermodynamic equilibrium in the ion velocity distribution functions (VDFs), measured by the Magnetospheric Multiscale (MMS) mission in the Earth's turbulent magnetosheath, is quantitatively investigated.…
Thermal electrons cannot directly participate in the process of diffusive acceleration at electron-ion shocks because their Larmor radii are smaller than the shock transition width: this is the well-known electron injection problem of…
Context. In a previous paper (Afify et al. 2024), we have investigated the stability threshold of the ion-ion acoustic instability (IIAI) in parameter regimes compatible with recent Parker Solar Probe (PSP, (Fox et al. 2016)) observations,…
We present a survey of 1D kinetic particle-in-cell simulations of quasi-parallel non-relativistic shocks to identify the environments favorable for electron acceleration. We explore an unprecedented range of shock speeds $v_{\rm sh}\approx…
We present for the first time the joint distribution of electron heat flux and electron plasma beta, and the joint distribution of core electron drift velocity and electron plasma beta using a statistically large dataset of solar wind…
Non-Maxwellian $\kappa$ electron energy distributions (EEDs) have been proposed in recent years to resolve the so-called ``electron temperature and abundance discrepancy problem'' in the study of planetary nebulae (PNe). Thus the need to…
In this paper we model the high-energy tail of observed solar energetic proton energy distributions with a kappa distribution function. We employ a technique for deriving the thermodynamic parameters of solar energetic proton populations…
The formation of the observed core-halo feature in the solar wind electron velocity distribution function is a long-time puzzle. In this letter based on the current knowledge of nanoflares we show that the nanoflare-accelerated electron…
Electron velocity distribution functions in the solar wind according to standard models consist of 4 components, of which 3 are symmetric - the core, the halo, and the superhalo, and one is magnetic field-aligned, beam-like population,…
The stability of weakly collisional plasmas is well represented by linear theory, and the generated waves play an essential role in the thermodynamics of these systems. The velocity distribution functions (VDF) characterizing kinetic…
Analysis of Mark 4 and LASCO C2, C3 coronagraph data shows that, at the distance $R \leq 6$ R$_\odot$ from the center of the Sun, the thickness of a CME-generated shock-wave front ($\delta_F$) may be of order of the proton mean free path.…
The classic optical nebular diagnostics [N II], [O II], [O III], [S II], [S III], and [Ar III] are employed to search for evidence of non-Maxwellian electron distributions, namely $\kappa$ distributions, in a sample of well-observed…
The effect of driving frequency in the range of 13.56 MHz to 73 MHz on electron energy distribution and electron heating modes in a 50 mTorr capacitively coupled argon plasma discharge is studied using 1D-3V particle-in-cell simulations.…
Nonthermal sources located above bright flare arcades, referred to as the "above-the-loop-top" sources, have been often suggested as the primary electron acceleration site in major solar flares. The X8.2 limb flare on 2017 September 10…
To understand the essential physics needed to reproduce magnetic reconnection events in 2.5-D particle-in-cell (PIC) simulations, we revisit the Geospace Environmental Modeling (GEM) setup. We set up a 2-D Harris current sheet (that also…
We present observations of electron energization in magnetic reconnection outflows during the pre-impulsive phase of solar flare SOL2012-07-19T05:58. During a time-interval of about 20 minutes, starting 40 minutes before the onset of the…
Using spectroscopic data, we support the possibility of suprathermal distributions of coronal ions by fitting the equivalent kappa functions to their emission line profiles. We fit different kappa and Gaussian model functions to line…
During the formation of large-scale structures in the universe, weak internal shocks are induced within the hot ICM, while strong accretion shocks arise in the WHIM within filaments, and the warm-cold gas in voids surrounding galaxy…
In this work, more than a dozen solar energetic particle (SEP) events are identified where the source region is magnetically well-connected to at least one spacecraft at 1~au. The observed intensity-time profiles, for all available proton…
Analysis of 8,804,545 electron velocity distribution functions (VDFs), observed by the $\mathit{Wind}$ spacecraft near 1 AU between January 1, 2005 and January 1, 2022, was performed to determine the spacecraft floating potential,…