Related papers: Are jets rotating at the launching?
In the solar convection zone, rotation couples with intensely turbulent convection to build global-scale flows of differential rotation and meridional circulation. Our sun must have rotated more rapidly in its past, as is suggested by…
We review the theoretical efforts to understand why pre-main-sequence stars spin much more slowly than expected. The first idea put forward was that massive stellar winds may remove substantial angular momentum. Since then, it has become…
Observations of accreting black holes often provoke suggestions that their jets precess. The precession is usually supposed to result from a combination of the Lense-Thirring effect and accretion disc viscosity. We show that this is…
We present the results of 2.5-dimensional resistive magnetohydrodynamic (MHD) simulations of the magnetic interaction between a weakly magnetized neutron star and its accretion disk. General relativistic effects are simulated by using the…
We present the results of a detailed kinematic analysis of a significant fraction of the known population of Galactic star clusters aimed at constraining the physical mechanisms driving the onset and evolution of cluster rotation. Our study…
A technique by which a spacecraft can interact with flows of ionized gas in space (the solar wind or interstellar medium) to be accelerated to velocities greater than the wind velocity is explored. Inspired by the dynamic soaring maneuvers…
There is now unequivocal evidence that the jets in FR I radio galaxies are initially relativistic, decelerating flows. On the assumption that they are axisymmetric and intrinsically symmetrical (a good approximation close to the nucleus),…
In the last decades there have been an increasing interest in improving the accuracy of spacecraft navigation and trajectory data. In the course of this plan some anomalies have been found that cannot, in principle, be explained in the…
Using the multi-wavelength data from the Atmospheric Imaging Assembly (AIA) on board the Solar Dynamics Observatory (SDO) spacecraft, we study a jet occurred in coronal hole near the northern pole of the Sun. The jet presented distinct…
Coronal jets are believed to be the miniature version of large-scale solar eruptions. In particular, the eruption of a mini-filament inside the base arch is suggested to be the trigger and even driver of blowout jets. Here we propose an…
Astrophysical jets, launched from the immediate vicinity of accreting black holes, carry away large amounts of power in a form of bulk kinetic energy of jet particles and electromagnetic flux. Here we consider a simple analytical model for…
I present the results of a multiyear survey of very low mass stars and brown dwarfs, at high spectral resolution. The spectra were gathered with the HIRES echelle at the Keck Observatory. Some of these objects are stellar and others are…
We review some of the reasons for believing that the generic core-collapse supernova is neutrino-driven, not MHD-jet driven. We include a discussion of the possible role of rotation in supernova blast energetics and morphology, and…
Small, impulsive jets commonly occur throughout the solar corona, but are especially visible in coronal holes. Evidence is mounting that jets are part of a continuum of eruptions that extends to much larger coronal mass ejections and…
Solar jets, characterized by small-scale plasma ejections along open magnetic field lines or the legs of large-scale coronal loops, play a crucial role in the dynamics of the solar atmosphere. Although spectral and EUV images have been…
We present high angular resolution millimeter wavelength continuum and 13CO(2-1) observations of the circumstellar disk surrounding the TTauri star DG Tauri. We show that the velocity pattern in the inner regions of the disk is consistent…
Non-relativistic, magnetically-driven jets are constructed by taking self-consistently into account the feedback on the underlying accretion disc. It is shown that such jets are mostly described by the ejection index $\xi= \mbox{d} \ln \dot…
Outflowing motions, whether a wind launched from the disk, a jet launched from the protostar, or the entrained molecular outflow, appear to be an ubiquitous feature of star formation. These outwards motions have a number of root causes, and…
Newly formed stars are often observed to possess circumstellar disks, from which mass continues to be accreted onto the star and fed into outflowing jets, and which eventually may evolve into dusty debris disks and planetary systems. Recent…
The dynamics of the coherent structures in jets generated by nozzles of different shapes is analyzed through DNS at $Re_{D_e}=565$, by considering circular, square, fractal and star-like nozzles. The jets generated from orifices with…