Related papers: Modeling the diffuse X-ray emission of Planetary N…
One key feature of the interacting stellar winds model of the formation of planetary nebulae (PNe) is the presence of shock-heated stellar wind confined in the central cavities of PNe. This so-called hot bubble should be detectable in…
We present a new synthetic model to follow the evolution of a planetary nebula (PN) and its central star, starting from the onset of AGB phase up to the white dwarf cooling sequence. The model suitably combines various analytical…
We carry out high resolution two-dimensional radiation-hydrodynamic numerical simulations to study the formation and evolution of hot bubbles inside planetary nebulae (PNe). We take into account the evolution of the stellar parameters, wind…
Two sources of X-ray emission are expected from planetary nebulae: the hot central stars with $T_{eff} > 10^5$ K, and shocked fast stellar winds at temperatures of 10$^6 - 10^7$ K. The stellar emission and nebular emission differ in spatial…
The radiation field of central stars of planetary nebulae (CSPNe) is crucial for determining the physical conditions of planetary nebulae (PNe). Many studies in the literature model PNe using the blackbody approximation (bb) or…
We calculate the X-ray emission from the shocked fast wind blown by the central stars of planetary nebulae (PNs) and compare with observations. Using spherically symmetric self similar solutions, we calculate the flow structure and X-ray…
This paper looks into various aspects brought to light by numerical work on the generalized interacting winds model for planetary nebulae. First, a detailed comparison between radiative and non-radiative models is made, showing that one's…
We conduct 2D numerical simulations of jets expanding into the slow wind of asymptotic giant branch stars. We show that the post-shock jets' material can explain the observed extended X-ray emission from some planetary nebulae (PNs). Such…
We present a homogeneous set of spectroscopic measurements secured with 4-meter class telescopes for a sample of 90 planetary nebulae (PNe) located in the direction of the Galactic bulge. We derive their plasma parameters and chemical…
XMM-Newton EPIC observations of the planetary nebula (PN) NGC 7009, the Saturn Nebula, have detected extended X-ray emission in its central cavity. The diffuse X-ray emission must originate in the shocked fast stellar wind. The spectra show…
Using a code that employs a self-consistent method for computing the effects of photoionization on circumstellar gas dynamics, we model the formation of wind-driven nebulae around massive Wolf-Rayet (W-R) stars. Our algorithm incorporates a…
We discuss our most recent findings on the diffuse X-ray emission from Wolf-Rayet (WR) nebulae. The best-quality X-ray observations of these objects are those performed by XMM-Newton and Chandra towards S308, NGC2359, and NGC6888. Even…
Close binary systems undergoing mass transfer or common envelope interactions can account for the morphological properties of some planetary nebulae. The search for close binary companions in planetary nebulae is hindered by the difficulty…
We present a possible evolutionary pathway to form planetary nebulae (PNe) with close neutron star (NS)-white dwarf (WD) binary central stars. By employing a comprehensive binary population synthesis technique we find that the evolution…
We present high resolution spectrophotometric data for 34 galactic planetary nebulae with [WC] nuclei (WRPNe).The sample includes PNe with early and late [WC] stars and some WELS. Physical conditions and chemical abundances have been…
Energetic pulsars power winds of relativistic leptons which produce photon nebulae (so- called pulsar wind nebulae, PWNe). Their spectral energy distribution has a double-humped structure: the first hump lies in the X-ray regime, the second…
The status of numerical hydrodynamical models for Planetary Nebulae is reviewed. Since all of the numerical work is based on the interacting winds model, we start with a description of this model and give an overview of the early analytical…
Planetary Nebulae (PNe) have been used satisfactory to test the effects of stellar evolution on the Galactic chemical environment. Moreover, a link exists between nebular morphology and stellar populations and evolution. We present the…
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…
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…