Related papers: A note on magnetized coronae
We investigate the formation of hot coronae and vertical outflows in accretion disks by magneto-rotational turbulence. We perform local three-dimensional (3D) MHD simulations with the vertical stratification by explicitly solving an energy…
Observations of the coronae of the Sun and of solar-like stars provide complementary information to advance our understanding of stellar magnetic activity, and of the processes leading to the heating of their outer atmospheres. While solar…
A hot corona is suggested to be above the standard thin disk. The anisotropy of hard X-ray emission in radio-quiet active galactic nuclei implies that the corona is not static and probably moves outwards like winds. We perform…
A large part of the hot corona consists of magnetically confined, bright plasma loops. These observed loops are in turn structured into bright strands. We investigate the relationship between magnetic field geometry, plasma properties and…
Like the solar corona, the external magnetic field of magnetars is twisted by surface motions of the star. The twist energy is dissipated over time. We discuss the theory of this activity and its observational status. (1) Theory predicts…
Relaxation of braided coronal magnetic fields through reconnection is thought to be a source of energy to heat plasma in active region coronal loops. However, observations of active region coronal heating associated with an untangling of…
The current status of understanding of the X-ray emission from Seyfert galaxies involves Comptonization of soft photons by hot subrelativistic electrons. After briefly reviewing the early theoretical basis for the presence of hot optically…
Heating mechanism in the solar atmosphere (from chromosphere to corona) is one of the top-challenges in modern astronomy. The classic mechanisms can be divided into two categories: wave heating (W) and magnetic reconnection heating (X).…
We present a systematic investigation of X-ray thermal coronae in 157 early-type galaxies and 22 late-type galaxies from a survey of 25 hot (kT>3 keV), nearby (z<0.05) clusters, based on CHANDRA archival data. Cool galactic coronae…
Hard x-ray emission, associated with hot electron preheat, in direct-drive implosions was observed to be enhanced by a factor of $1.5\pm0.1$ by application of a $10$ T magnetic field. The applied magnetic field reaches a quasi steady-state…
This publication provides an overview of magnetic fields in the solar atmosphere with the focus lying on the corona. The solar magnetic field couples the solar interior with the visible surface of the Sun and with its atmosphere. It is also…
The high-energy emission ($400$ keV $- 2$ MeV) of Cygnus X-1 --the most well-studied Galactic black hole-- was recently found to be strongly polarized. The origin of this radiation is still unknown. In this work, we suggest that it is the…
The solar corona, anomalously hot outer atmosphere of the Sun, is traditionally described by magnetohydrodynamic, fluid-like approach. Here we review some recent developments when, instead, a full kinetic description is used. It is shown…
The magnetic field plays a crucial role in heating the solar corona, but the exact energy release mechanism(s) is(are) still unknown. Here, we investigate in detail, the process of magnetic energy release in a situation where two initially…
A broad variety of observational methods allows us to see the effect of magnetic reconnection in high-temperature strongly-magnetized plasma of the solar corona. Some specific features of the large-scale reconnection in large solar flares…
It is extremely difficult to simulate the details of coronal heating and also make meaningful predictions of the emitted radiation. Thus, testing realistic models with observations is a major challenge. Observational signatures of coronal…
The corona of the Sun is dominated by emission from loop-like structures. When observed in X-ray or extreme ultraviolet emission, these million K hot coronal loops show a more or less constant cross section. In this study we show how the…
The magnetic field governs the corona; hence it is a crucial parameter to measure. Unfortunately, existing techniques for estimating its strength are limited by strong assumptions and limitations. These techniques include photospheric or…
Determining the heating mechanism (or mechanisms) that causes the outer atmosphere of the Sun, and many other stars, to reach temperatures orders of magnitude higher than their surface temperatures has long been a key problem. For decades…
Since the first discovery of an extrasolar planetary system more than a decade ago, hundreds more have been discovered. Surprisingly, many of these systems harbor Jupiter-class gas giants located close to the central star, at distances of…