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<jats:title>Abstract</jats:title> <jats:p>An analysis of model fit results of 15,210 electron velocity distribution functions (VDFs), observed within ±2 hr of 52 interplanetary (IP) shocks by the Wind spacecraft near 1 au, is presented as the third and final part on electron VDFs near IP shocks. The core electrons and protons dominate in the magnitude and change in the partial-to-total thermal pressure ratio, with the core electrons often gaining as much or more than the protons. Only a moderate positive correlation is observed between the electron temperature and the kinetic energy change across the shock, while weaker, if any, correlations were found with any other macroscopic shock parameter. No VDF parameter correlated with the shock normal angle. The electron VDF evolves from a narrowly peaked core with flaring suprathermal tails in the upstream to either a slightly hotter core with steeper tails or much hotter flattop core with even steeper tails downstream of the weaker and strongest shocks, respectively. Both quasi-static and fluctuating fields are examined as possible mechanisms modifying the VDF, but neither is sufficient alone. For instance, flattop VDFs can be generated by nonlinear ion acoustic wave stochastic acceleration (i.e., inelastic collisions), while other work suggested they result from the combination of quasi-static and fluctuating fields. This three-part study shows that not only are these systems not thermodynamic in nature; even kinetic models may require modification to include things like inelastic collision operators to properly model electron VDF evolution across shocks or in the solar wind.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>The intergalactic medium (IGM) at <jats:italic>z</jats:italic> ∼  5 to 6 is largely ionized, and yet the main source for the IGM ionization in the early universe is uncertain. Of the possible contributors are faint quasars with <jats:inline-formula> <jats:tex-math> <?CDATA $-26\lesssim {M}_{1450}\lesssim -23$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjab7bdeieqn1.gif" xlink:type="simple" /> </jats:inline-formula>, but their number density is poorly constrained at <jats:italic>z</jats:italic> ∼ 5. In this paper, we present our survey of faint quasars at <jats:italic>z</jats:italic> ∼ 5 in the European Large-Area <jats:italic>Infrared Space Observatory</jats:italic> Survey-North 1 (ELAIS-N1) field over a survey area of 6.51 deg<jats:sup>2</jats:sup> and examine if such quasars can be the dominant source of the IGM ionization. We use the deep optical/near-infrared data of the ELAIS-N1 field as well as the additional medium-band observations to find <jats:italic>z</jats:italic> ∼ 5 quasars through a two-step approach using the broadband color selection, and spectral energy distribution fitting with the medium-band information included. Adopting Bayesian information criterion, we identify 10 promising quasar candidates. Spectra of three of the candidates are obtained, confirming all of them to be quasars at <jats:italic>z</jats:italic> ∼ 5 and supporting the reliability of the quasar selection. Using the promising candidates, we derive the <jats:italic>z</jats:italic> ∼ 5 quasar luminosity function at −26 ≲ <jats:italic>M</jats:italic> <jats:sub>1450</jats:sub> ≲ −23. The number density of faint <jats:italic>z</jats:italic> ∼ 5 quasars in the ELAIS-N1 field is consistent with several previous results that quasars are not the main contributors to the IGM-ionizing photons at <jats:italic>z</jats:italic> ∼ 5.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Characterizing the large-scale structure and plasma properties of the inner corona is crucial to understanding the source and subsequent expansion of the solar wind and related space weather effects. Here, we apply a new coronal rotational tomography method, along with a method to narrow streamers and refine the density estimate, to COR2A/Solar Terrestrial Relations Observatory observations from a period near solar minimum and maximum, gaining density maps for heights between 4 and 8<jats:italic>R</jats:italic> <jats:sub>⊙</jats:sub>. The coronal structure is highly radial at these heights, and the streamers are very narrow: in some regions, only a few degrees in width. The mean densities of streamers is almost identical between solar minimum and maximum. However, streamers at solar maximum contain around 50% more total mass due to their larger area. By assuming a constant mass flux, and constraints on proton flux measured by Parker Solar Probe (PSP), we estimate an outflow speed within solar minimum streamers of 50–120 kms<jats:sup>−1</jats:sup> at 4<jats:italic>R</jats:italic> <jats:sub>⊙</jats:sub>, increasing to 90–250 kms<jats:sup>−1</jats:sup> at 8<jats:italic>R</jats:italic> <jats:sub>⊙</jats:sub>. Accelerations of around 6 ms<jats:sup>−2</jats:sup> are found for streamers at a height of 4<jats:italic>R</jats:italic> <jats:sub>⊙</jats:sub>, decreasing with height. The solar maximum slow wind shows a higher acceleration to extended distances compared with solar minimum. To satisfy the solar wind speeds measured by PSP, there must be a mean residual acceleration of around 1–2 ms<jats:sup>−2</jats:sup> between 8 and 40<jats:italic>R</jats:italic> <jats:sub>⊙</jats:sub>. Several aspects of this study strongly suggest that the coronal streamer belt density is highly variable on small scales, and that the tomography can only reveal a local spatial and temporal average.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>Recent analysis of high-cadence white-light images taken by the <jats:italic>Solar-Terrestrial RElations Observatory</jats:italic> near solar maximum has revealed that outflowing density structures are released in a ubiquitous manner in the solar wind. The present study investigates whether these density fluctuations could originate from the transient heating of the low corona observed during coronal bright points (CBPs). We assume that part of the intense heating measured during CBPs occurs at the coronal base of open magnetic fields that channel the forming solar wind. We employ the solar wind model MULTI-VP to quantify the plasma compression induced by transient heating and investigate how the induced perturbation propagates to the upper corona. We show that for heating rates with statistics comparable to those observed during CBPs, the compressive wave initially increases the local plasma density by a factor of up to 50% at 5 <jats:italic>R</jats:italic> <jats:sub>⊙</jats:sub>. The wave expands rapidly beyond 30 solar radii and the local enhancement in density decreases beyond. Based on the occurrence rates of CBPs measured in previous studies, we impose transient heating events at the base of thousands of open magnetic field lines to study the response of the entire 3D corona. The simulated density cubes are then converted into synthetic white-light imagery. We show that the resulting brightness variations occupy all position angles in the images on timescales of hours. We conclude that a significant part of the ubiquitous brightness variability of the solar corona could originate in the strong transient heating of flux tubes induced by CBPs.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>We discuss the production of multiple astrophysical messengers (neutrinos, cosmic rays, gamma-rays) in the Gamma-Ray Burst (GRB) internal shock scenario, focusing on the impact of the collision dynamics between two shells on the fireball evolution. In addition to the inelastic case, in which plasma shells merge when they collide, we study the Ultra Efficient Shock scenario, in which a fraction of the internal energy is re-converted into kinetic energy and, consequently, the two shells survive and remain in the system. We find that in all cases, a quasi-diffuse neutrino flux from GRBs at the level of 10<jats:sup>−11</jats:sup>–<jats:inline-formula> <jats:tex-math> <?CDATA ${10}^{-10}\,\mathrm{GeV}\,{\mathrm{cm}}^{-2}\,{{\rm{s}}}^{-1}\,{\mathrm{sr}}^{-1}$?> </jats:tex-math> <jats:inline-graphic xmlns:xlink="http://www.w3.org/1999/xlink" xlink:href="apjab7ea7ieqn1.gif" xlink:type="simple" /> </jats:inline-formula> (per flavor) is expected for protons and a baryonic loading of 10, which is potentially within the reach of IceCube-Gen2. The highest impact of the collision model for multi-messenger production is observed for the Ultra Efficient Shock scenario, that promises high conversion efficiencies from kinetic to radiated energy. However, the assumption that the plasma shells separate after a collision and survive as separate shells within the fireball is found to be justified too rarely in a multicollision model that uses hydrodynamical simulations with the <jats:sc>PLUTO</jats:sc> code for individual shell collisions.</jats:p>

<jats:title>Abstract</jats:title> <jats:p>In order to obtain an overview of gamma-ray bursts (GRBs), we need a full sample. In this paper, we collected 6289 GRBs (from GRB 910421 to GRB 160509A) from the literature, including their prompt emission, afterglow, and host galaxy properties. We hope to use this large sample to reveal the intrinsic properties of GRBs. We have listed all of the data in machine-readable tables, including the properties of the GRBs, correlation coefficients and linear regression results of two arbitrary parameters, and linear regression results of any three parameters. These machine-readable tables could be used as a data reservoir for further studies on the classifications or correlations. One may find some intrinsic properties from these statistical results. With these comprehensive tables, it is possible to find relations between different parameters and to classify the GRBs into different subgroups. Upon completion, they may reveal the nature of GRBs and may be used as tools like pseudo-redshift indicators, standard candles, etc. All of the machine-readable data and statistical results are available.</jats:p>