Related papers: Spoke formation under moving plasma clouds
The formation of planets is one of the major unsolved problems in modern astrophysics. Planets are believed to form out of the material in circumstellar disks known to exist around young stars, and which are a by-product of the star…
HI observations have revealed in several shell galaxies the presence of gaseous shells slightly displaced from the stellar shells radially, in the outward direction. We propose a mechanism to form this gaseous shells, based on the…
It has been conjectured that the velocity of sound in any medium is smaller than the velocity of light in vacuum divided by $\sqrt{3}$. Simple arguments support this bound in non-relativistic and/or weakly coupled theories. The bound has…
Whistler-mode waves are generated within and can propagate upstream of collisionless shocks. They are known to play a role in electron thermodynamics/acceleration and, under certain conditions, are markedly observed as wave trains preceding…
Ring structures are observed by (sub-)millimeter dust continuum emission in various circumstellar disks from early stages of Class 0 and I to late stage of Class II young stellar objects (YSOs). In this paper, we study one of the possible…
Radio images of protoplanetary disks demonstrate that dust grains tend to organize themselves into rings. These rings may be a consequence of dust trapping within gas pressure maxima wherein the local high dust-to-gas ratio is expected to…
It is shown that pulsar radio emission can be generated effectively through a streaming motion in the polar-cap regions of a pulsar magnetosphere causing nonresonant growth of waves that can escape directly. As in other beam models, a…
We analyze several thousand Cassini ISS images in order to study the inner edge of the Keeler gap in Saturn's outer A ring. We find strong evidence for an m=32 perturbation with a mean amplitude of radial variation of 4.5 km. Phase analysis…
Rotating, turbulent cosmic fluids are generally pervaded by coherent structures such as vortices and magnetic flux tubes. The formation of such structures is a robust property of rotating turbulence as has been confirmed in computer…
In this article, we investigate experimentally and numerically the time evolution of vortex rings generated by the translation of a rigid disk in a fluid initially at rest and submitted to an acceleration followed by a deceleration. The…
We investigate the formation and evolution of circumstellar disks in turbulent cloud cores until several 104 years after protostar formation using smoothed particle hydrodynamics (SPH) calculations. The formation and evolution process of…
We present initial results of the first self-consistent numerical model of the outer magnetosphere of a pulsar. By using the relativistic ``particle-in-cell'' method with special boundary conditions to represent plasma dynamics in 3D, we…
We use a semi-analytic circumstellar disk model that considers movement of the snow line through evolution of accretion and the central star to investigate how gas giant frequency changes with stellar mass. The snow line distance changes…
We propose that bound, young massive stellar clusters form from dense clouds that have escape speeds greater than the sound speed in photo-ionized gas. In these clumps, radiative feedback in the form of gas ionization is bottled up,…
In the ionization region above circular planar magnetrons well defined regions of high emissivity are observed, when the discharge is driven in the HiPIMS regime. Once their mode is stabilized, these structures rotate in the E x B direction…
We suppose that some large trans-Neptunian objects could be formed directly by the compression of rarefied dust condensations of the protoplanetary disk, but not by the accretion of smaller planetesimals. About 0.0015 of former…
Soap bubbles can be easily generated by varies methods, while their formation process is complicated and still worth study. A model about the bubble formation process was proposed in Phys. Rev. Lett. 116, 077801 recently, and it was…
We study the vertical extent of propeller structures in Saturn's rings. Our focus lies on the gap region of the propeller and on non-inclined propeller moonlets. In order to describe the vertical structure of propellers we extend the model…
It is proposed that radiation belts similar to the ones in the planetary magnetosphere can exist for a pulsar with a relatively long period and a strong magnetic field. In the belts located in the closed field line region near the light…
Many scientific reports document that asymptomatic and presymptomatic individuals contribute to the spread of COVID-19, probably during conversations in social interactions. Droplet emission occurs during speech, yet few studies document…