Related papers: Low-ionization structures in planetary nebulae: co…
Fifty five planetary nebulae containing micro-structures of low-ionization (LIS) are analyzed in this review in terms of LIS morphology, kinematics, and physical and excitation properties. We attempt to address the issue of their origin…
Though the small-scale, low-ionization knots, filaments and jets (LISs) of planetary nebulae (PNe) are known for ~30yr, some of their observational properties are not well established. In consequence our ability to include them in the wider…
We are developing a project aimed at studying the physical properties, origin and evolution of low-ionization structures in planetary nebulae. Within this project we have identified a number of pairs of highly collimated low-ionization…
Context. Low-ionization structures (LISs), found in all morphological types of planetary nebulae (PNe), are small-scale features prominent in emission from low-ionization species such as [N ii], [S ii], [O ii] and [O i]. Observational and…
Planetary nebulae (PNe) are known to possess a variety of small-scale structures that are usually in a lower ionization state than the main body of the nebulae. The morphological and kinematic properties of these low-ionization structures…
Nearly 30 years after the first detailed studies of low-ionization structures (LISs) in planetary nebulae (PNe), we perform a statistical analysis of their physical, chemical and excitation properties, by collecting published data in the…
We are carrying out a study of the physical parameters and excitation of low-ionization structures (LIS) in planetary nebulae (PNe). Since the optical morphology and kinematics of the LIS and the main components (rims, shells and haloes) of…
We present new results of a program aimed at studying the physical properties, origin and evolution of those phenomena which go under the somewhat generic definition of "low-ionization, small-scale structures in PNe". We have obtained…
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…
We present an alternative model for the formation of fast low-ionization emission regions (FLIERs) in planetary nebulae that is able to account for many of their attendant characteristics and circumvent the problems on the…
Some fast-moving pulsars, like the Guitar and the Lighthouse, exhibit asymmetric non-thermal emission features that extend well beyond their ram pressure confined pulsar wind nebulae (PWNe). Using 3D relativistic simulations we explain…
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…
Aims. Numerous planetary nebulae show complicated inner structures not obviously explained. For one such object we undertake a detailed 3D photoionization and kinematical model analysis for a better understanding of the underlying shaping…
We conduct three-dimensional hydrodynamical simulations of two opposite jets launched from a binary stellar system into a previously ejected shell and show that the interaction can form barrel-like and H-like shapes in the descendant…
Highly collimated supersonic jets and less collimated outflows are observed to emerge from a wide variety of astrophysical objects. They are seen in young stellar objects (YSOs), proto-planetary nebulae, compact objects (like galactic black…
We conduct numerical simulations of axisymmetrical jets expanding into a spherical AGB slow wind. The three-dimensional flow is simulated with an axially symmetric numerical code. We concentrate on jets that are active for a relatively…
The physico-chemical properties of the planetary nebula (PN) NGC 3242 are investigated in both 1D and 2D, using Integral Field Unit (IFU) data. This PN has a complex morphology with multiple shells and contains a pair of structures with a…
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…
We present results of an ongoing survey of low surface brightness planetary nebulae (PNe). Using both narrow-band imaging and long slit spectroscopy we have studied 15 new examples for interaction with the interstellar medium (ISM)…
Low-ionisation structures (LISs) are commonly found in planetary nebulae (PNe) but they are still poorly understood. The recent discovery of unforeseen molecular hydrogen gas (H2) has changed what we think we know about these…