Related papers: The Last Hurrah: PPN Formation by a Magnetic Explo…
Forming massive stars launch outflows of magnetic origin, which in fact serve as a marker for finding sites of massive star formation. However, both the theoretical and observational study of the mechanisms that intervene in the formation…
As it is well-known that the hydrodinamic collapse of the massive star iron core should lead to the production of a hot neutron star. The assumption is made that the thermonuclear burning of the envelope matter, accreting onto the hot…
Mass loss is a determinant factor which strongly affects the evolution and the fate of massive stars. At low metallicity, stars are supposed to rotate faster than at the solar one. This favors the existence of stars near the critical…
The pattern of variations in the intensity of magnetodipole losses is studied with the relativistic effect of magnetic-field dissipation during collapse into a black hole taken into account. A burst-type solution can be obtained both for a…
Solar eruptions are due to a sudden destabilization of force-free coronal magnetic fields. But the detailed mechanisms which can bring the corona towards an eruptive stage, then trigger and drive the eruption, and finally make it explosive,…
Energetic outflows from main sequence stars accreting mass at very high rates might account for the powering of some eruptive objects, such as merging main sequence stars, major eruptions of luminous blue variables, e.g., the Great Eruption…
Star formation is thought to be triggered by the gravitational collapse of the dense cores of molecular clouds. Angular momentum conservation during the collapse results in the progressive increase of the centrifugal force, which eventually…
(Abridged) We propose that giant flares on Soft Gamma-Ray Repeaters produce relativistic, strongly magnetized, weakly baryon loaded magnetic clouds, somewhat analogous to solar coronal mass ejection (CME) events. Flares are driven by…
If the first (PopIII) stars were very massive, their final fate is to collapse into very massive black holes. Once a proto-black hole has formed into the stellar core, accretion continues through a disk. It is widely accepted, although not…
We present 2D results of simulations of the magnetorotational core collapsed supernova. For the first time we obtain strong explosion for the core collapsed supernova. In 2D approximation we show that amplification of the toroidal magnetic…
Planetary nebulae (PNe) are circumstellar gas ejected during an intense mass-losing phase in the the lives of asymptotic giant branch stars. PNe have a stunning variety of shapes, most of which are not spherically symmetric. The debate over…
The driving mechanism of massive outflows observed in high-mass star-forming regions is investigated using three-dimensional magnetohydrodynamics (MHD) and protostellar evolution calculations. In our previous paper, we showed that the mass…
Our current understanding of the physical processes of star formation is reviewed, with emphasis on processes occurring in molecular clouds like those observed nearby. The dense cores of these clouds are predicted to undergo gravitational…
We suggest that part of the infalling material during the core-collapse of a massive star goes into orbit around the compact core to form a hot, dense, centrifugally-supported accretion disk whose evolution is strongly influenced by…
Some accreting neutron stars and young stars show unexplained episodic flares in the form of quasi-periodic oscillations or recurrent outbursts. In a series of two papers we present new work on an instability that can lead to episodic…
We consider the spin evolution of highly magnetized neutron stars in a hypercritical inflow just after their birth in supernovae. Presence of a strong magnetic field could deform the star and if the symmetry axis of the field is misaligned…
Rotating and magnetized protoneutron stars (PNSs) may drive relativistic magneto-centrifugally accelerated winds as they cool immediately after core collapse. The wind fluid near the star is composed of neutrons and protons, and the…
We study the physics behind the neutrino-driven mechanism for gamma-ray bursts and hypernovae, deriving the critical density at which these outbursts occur in the collapsar model. The agreement between this derivation and results from past…
Numerical simulations of outflows formed during the collapse of 100 M_sun cloud cores are presented. We derive a generalised criterion from MHD wind theory to analyse the launching mechanism of these outflows. The criterion is successfully…
Current models of magnetars require extremely strong magnetic fields to explain their observed quiescent and bursting emission, implying that the field strength within the star's outer crust is orders of magnitude larger than the dipole…