Related papers: X-ray Observations of Planetary Nebulae
Our understanding of Pulsar Wind Nebulae (PWNe), has greatly improved in the last years thanks to unprecedented high resolution images taken from the HUBBLE, CHANDRA and XMM satellites. The discovery of complex but similar inner features,…
Pulsars are known to be efficient accelerators that produce copious amounts of relativistic particles and inject them into the Galactic medium. The radiation emitted by such a pulsar wind can be seen from radio through gamma-rays as a…
Observations with powerful X-ray telescopes, such as XMM-Newton and Chandra, significantly advance our understanding of massive stars. Nearly all early-type stars are X-ray sources. Studies of their X-ray emission provide important…
In latest years, the high sensitivity of the instruments on-board the XMM-Newton and Chandra satellites allowed us to explore the properties of the X-ray emission from hot subdwarf stars. The small but growing sample of X-ray detected hot…
X-ray emitting diffuse nebulae around hot stars are observed to have soft-band temperatures in the narrow range [1-3]$\times10^{6}$ K, independent of the stellar wind parameters and the evolutionary stage of the central star. We discuss the…
We review observations of several classes of neutron-star-powered outflows: pulsar-wind nebulae (PWNe) inside shell supernova remnants (SNRs), PWNe interacting directly with interstellar medium (ISM), and magnetar-powered outflows. We…
Planetary nebulae (PNe) represent the near endpoints of evolution for stars of initial mass $\sim$1-8 $M_\odot$, wherein the envelope of an asymptotic giant branch (AGB) star becomes photodissociated and ionized by high-energy radiation…
Pulsars are rapidly-rotating neutron stars born out of the death of stars. A diffuse nebula is formed when particles stream from these neutron stars and interact with the ambient medium. These pulsar wind nebulae (PWNe) are visible across…
Thanks to the high sensitivity of the instruments on board the XMM-Newton and Chandra satellites, it has become possible to explore the properties of the X-ray emission from hot subdwarfs. The small but growing sample of hot subdwarfs…
We present theoretical results of a piecewise isothermal shock wind model devised for predicting the luminosity and surface brightness profile of diffuse X-ray emissions primarily from the inner shocked downstream wind zone of a planetary…
Pulsar winds shocked in the ambient medium produce spectacular nebulae observable from the radio through gamma-rays. The shape and the spectrum of a pulsar wind nebula (PWN) depend on the angular distribution, magnetization and energy…
We review multiwavelength properties of pulsar wind nebulae (PWNe) created by supersonically moving pulsars and the effects of pulsar motion on the PWN morphologies and the ambient medium. Supersonic pulsar wind nebulae (SPWNe) are…
The number of plausible associations of extended VHE (TeV) sources with pulsars has been steadily growing, suggesting that many of these sources are pulsar wind nebulae (PWNe). Here we overview the recent progress in X-ray and TeV…
We present results from the most recent set of observations obtained as part of the Chandra X-ray observatory Planetary Nebula Survey (ChanPlaNS), the first comprehensive X-ray survey of planetary nebulae (PNe) in the solar neighborhood…
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…
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…
We present the results of Chandra X-ray Observatory (CXO) observations of the planetary nebulae (PNs) NGC 40 and Hen 2-99. Both PNs feature late-type Wolf-Rayet central stars that are presently driving fast ~1000 km/s, massive winds into…
A review of recent observations of the kinematics of six objects that represent the broad range of phenomena called planetary nebulae (PNe) is presented. It is demonstrated that Hubble-type outflows are predominant, consequently it is…
Planetary Nebulae (PNe) are very important kinematical tracers of the outer regions of early-type galaxies, where the integrated light techniques fail. Under ad hoc assumptions, they allow measurements of rotation velocity and velocity…
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…