Related papers: Heating and Ionization of X-Winds
In the context of the solar atmosphere, we re-examine the role of of neutral and ionized species in dissipating the ordered energy of intermediate-mode MHD waves into heat. We solve conservation equations for the hydrodynamics and for…
While it may seem counterintuitive that X-ray astronomy should give any insights into low-temperature planetary systems, planets orbit stars whose magnetized surfaces divert a small fraction of the stellar energy into high energy products:…
Magnetic, radiation pressure, and thermal driving are the three mechanisms capable of launching accretion disk winds. In X-ray binaries, radiation pressure is often not significant, as in many systems the luminosity is too low for driving…
We compute rest-frame reflection spectra and the corresponding energy-dependent linear polarization degree and angle for (un)polarized single-temperature blackbody spectra impinging on a partially ionized constant-density optically thick…
We investigate the interaction between the magnetized stellar wind plasma and the partially ionized hydrodynamic hydrogen outflow from the escaping upper atmosphere of non- or weakly magnetized hot Jupiters. We use the well-studied hot…
The differential heating of electrons and ions by turbulence in weakly collisional magnetized plasmas and the scales at which such energy dissipation is most effective are still debated. Using a large data sample measured in the Earth's…
We calculate the ionization fraction of protostellar alpha disks, taking into account vertical temperature structure, and the possible presence of trace metal atoms. Both thermal and X-ray ionization are considered. Previous investigations…
Although the mechanisms responsible for heating the Sun's corona and accelerating the solar wind are still being actively investigated, it is largely accepted that photospheric motions provide the energy source and that the magnetic field…
We present a further investigation into the increased ionization observed in element charge states in the fast solar wind compared to its coronal hole source regions. Once ions begin to be perpendicularly heated by ion cyclotron waves and…
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…
Many ultracompact HII regions exhibit a cometary morphology in radio continuum emission. In such regions, a young massive star is probably ablating, through its ultraviolet radiation, the molecular cloud clump that spawned it. On one side…
The discrepancy between expected and observed cooling rates of X-ray emitting gas has led to the {\it cooling flow problem} at the cores of clusters of galaxies. A variety of models have been proposed to model the observed X-ray spectra and…
By making spectral absorption-line observations of disk galaxies at intermediate inclinations, we have been able to determine the amplitude of their constituent stars' random motions in three dimensions. This full measure of the shape of…
In this paper, we study the heating of the magnetized solar chromosphere induced by the large fraction of neutral atoms present in this layer. The presence of neutrals, together with the decrease with height of the collisional coupling,…
Characterizing the plasma state in the near-Sun environment is essential to constrain the mechanisms that heat and accelerate the solar wind. In this study, we use Parker Solar Probe (PSP) observations from Encounters 1 through 24 to…
Several gamma-ray binaries show extended X-ray emission that may be associated to interactions of an outflow with the medium. Some of these systems are, or may be, high-mass binaries harboring young nonaccreting pulsars, in which the…
LS 5039 has been observed with several X-ray instruments so far. The source presents X-ray variability at orbital timescales in flux and photon index. The system harbors an O-type main sequence star with moderate mass loss. At present, the…
Polytropic models of stellar winds remain to be useful tools because they allow for a simple description of the energy balance of the expanding plasma without explicitly specifying potentially complex energy transport processes like, e.g.,…
A subset (~ 10%) of massive stars present strong, globally ordered (mostly dipolar) magnetic fields. The trapping and channeling of their stellar winds in closed magnetic loops leads to magnetically confined wind shocks (MCWS), with…
Protoplanetary disks are mainly heated by radiation from the central star. Since the incident stellar flux at any radius is sensitive to the disk structure near that location, an unstable feedback may be present. Previous investigations…