Related papers: Faint emission lines in planetary nebulae with a […
Small cationic fullerene fragments, produced by electron impact ionization of C60, were mass-selected and accumulated in cryogenic Ne matrixes. Optical absorption spectroscopy of these fragments with up to 18 carbon atoms revealed linear…
We present spectroscopy of three hydrogen-deficient central stars of faint planetary nebulae, with effective temperatures ($T_\mathrm{eff}$) in excess of 100,000 K. The nucleus of RaMul 2 is a Population II Wolf-Rayet star of spectral type…
During the start of a survey program using FORS2 long slit spectroscopy on planetary nebulae (PN) and their haloes, we serendipitously discovered six background emission line galaxies (ELG) with redshifts of z = 0.2057, 0.3137, 0.37281,…
We have used the Cornish radio catalogue combined with the use of multi-wavelength data to identify 62 new Planetary Nebula (PN) candidates close to the Galactic mid-plane. Of this sample 11 have weak optical counterparts in deep narrow…
We present high quality optical spectroscopic observations of the planetary nebula (PN) Hf 2-2. The spectrum exhibits many prominent optical recombination lines (ORLs) from heavy element ions. Analysis of the H {\sc i} and He {\sc i}…
We performed Herschel/HIFI observations of intermediate-excitation molecular lines in the far-infrared/submillimeter range in a sample of ten protoplanetary nebulae and young planetary nebulae. The high spectral resolution provided by HIFI…
CONTEXT: Until now, only one planetary nebula (PN) has been known in the Fornax dwarf spheroidal galaxy. AIMS: The discovery of a second PN candidate, associated with one of the 5 globular clusters in the Fornax dwarf, is reported. METHODS:…
We present observations of planetary nebulae with the LOw Frequency ARray (LOFAR) between 120 and 168 MHz. The images show thermal free-free emission from the nebular shells. We have determined the electron temperatures for spatially…
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…
Echelle spectrophotometry of the planetary nebula NGC 5307 is presented. The data consists of VLT UVES observations in the 3100 to 10360 A range. Electron temperatures and densities have been determined using different line intensity…
We present an overview of the initial results from the Chandra Planetary Nebula Survey (ChanPlaNS), the first systematic (volume-limited) Chandra X-ray Observatory survey of planetary nebulae (PNe) in the solar neighborhood. The first phase…
Emission line at the energy ~3.55 keV detected in different galaxies and galaxy clusters has caused a lot of discussion in high-energy astrophysics and particle physics communities. To reveal the origin of the line, we analyzed publicly…
I explore the effects of observational errors on nebular chemical abundances using a sample of 179 optical spectra of 42 planetary nebulae (PNe) observed by different authors. The spectra are analysed in a homogeneous way to derive physical…
The optical line and continuum emission in the very high ionization Galactic planetary nebula (PN) NGC 4361 (PN G294.1 +43.6), has been mapped with VLT MUSE Wide Field normal mode (4750-9300A) commissioning observations. The PN is larger…
We present results from an Halpha emission-line survey in a one square degree area centered on the Orion Nebula Cluster, obtained with the Wide Field Grism Spectrograph-2 on the 2.2-meter telescope of the University of Hawaii. We identified…
Context. There are more than 3000 true and probable known Galactic Planetary Nebulae (PNe), but only for 13% of them there is central star spectroscopic information available. Aims. To contribute to the knowledge of central stars of…
We present near-infrared spectra of ten planetary nebulae (PNe) in the Large and Small Magellanic Clouds (LMC and SMC), acquired with the FIRE and GNIRS spectrometers on the 6.5-m Baade and 8.1-m Gemini South Telescopes, respectively. We…
We present near-IR narrow-band continuum-subtracted images in the H$_2$ $2.122\mu$m, and Br$\gamma$ $2.166\mu$m emission lines for a sample of 15 bipolar planetary nebulae. H$_2$ emission was definitely detected for most of the objects in…
This paper discusses the location of a sample of planetary nebulae on the HR diagram. We determine the internal velocity fields of 14 planetary nebulae from high-resolution echelle spectroscopy, with the help of photoionization models. The…
Although the planetary nebula NGC 6781 appears to possess an elliptical morphology, its kinematic and emission characteristics are in many ways unusual, and it is possible that it may represent a bipolar source oriented close to the line of…