Related papers: Bubbles in Planetary Nebulae and Clusters of Galax…

We show that a fast wind that expands into a bipolar nebula composed of two opposite jet-inflated bubbles can form a pair of bipolar rings around giant stars. Our model assumes three mass loss episodes: a spherical slow and dense shell, two…

I derive the condition for narrow jets with varying axis, e.g., precessing jets, to inflate more or less spherical (fat) bubbles in planetary nebulae and clusters of galaxies. This work follows a previous work dealing with wide jets, i.e.,…

I point to an interesting similarity in the morphology and some non-dimensional quantities between pairs of X-ray-deficient bubbles in clusters of galaxies and pairs of optical-deficient bubbles in planetary nebulae (PNs). This similarity…

I conduct an analytical study of the interaction of jets, or a collimated fast wind (CFW), with a previously blown asymptotic giant branch (AGB) slow wind. Such jets (or CFWs) are supposedly formed when a compact companion, a main sequence…

I argue that the high percentage of PNe that are shaped by jets show that main sequence stars in binary systems can accrete mass at a high rate from an accretion disk and launch jets. Not only this allows jets to shape PNe, but this also…

Planetary Nebulae represent a powerful window into the evolution of low-intermediate mass stars that have undergone extensive mass-loss. The nebula manifests itself in an extremely wide variety of shapes, but exactly how the mass lost is…

I calculate the specific angular momentum of mass accreted by a binary system embedded in the dense wind of a mass losing asymptotic giant branch star. The accretion flow is of the Bondi-Hoyle-Lyttleton type. For most of the relevant…

We conduct a three-dimensional hydrodynamical simulation to study the interaction of two opposite inclined jets inside the envelope of a giant star, and find that the jets induce many vortexes inside the envelope and that they efficiently…

I derive constraints on jet properties for inflating pairs of bubbles in planetary nebulae and clusters of galaxies. This work is motivated by the similarity in morphology and some non-dimensional quantities between X-ray-deficient bubbles…

We conduct three-dimensional hydrodynamical simulations of two opposite jets launched obliquely to the orbital plane around an asymptotic giant branch (AGB) star and within its dense wind, and demonstrate the formation of a `messy'…

This paper reviews our knowledge on binary central stars of planetary nebulae and presents some personal opinions regarding their evolution. Three types of interactions are distinguished: type I, where the binary companion induces the mass…

Binarity among stellar clusters in galaxy is such a reality which has been realized for a long time, but still hides several questions and problems to be solved. Some of binary star clusters are formed by close encounter, but the others are…

This work presents three dimensional, magneto-hydrodynamical simulations of the formation and early evolution of a subgroup of planetary nebulae that exhibit a variety of point-symmetric structures. For bipolar nebulae, the formation of…

It is widely believed that central star binarity plays an important role in the formation and evolution of aspherical planetary nebulae, however observational support for this hypothesis is lacking. Here, we present the most recent results…

Stars are generally spherical, yet their gaseous envelopes often appear non-spherical when ejected near the end of their lives. This quirk is most notable during the planetary nebula phase when these envelopes become ionized. Interactions…

The morphology of planetary nebulae emerging from the common envelope phase of binary star evolution is investigated. Using initial conditions based on the numerical results of hydrodynamical simulations of the common envelope phase it is…

Fast highly-collimated outflows including bipolar knots, jet-like features, and point-symmetric filaments or string of knots are common in planetary nebulae (PNe). These features, generally named as jets, are thought to play an active role…

The star formation process in molecular clouds usually leads to the formation of multiple stellar systems, mostly binaries. Remaining disks around those stars may be located around individual stars (circumstellar disks) or around the entire…

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…

We simulate the formation of bipolar planetary nebulae (PNe) through very short impulsive mass ejection events from binary systems, where the asymptotic giant branch (AGB) star ejects a mass shell that is accelerated by jets launched from a…