Related papers: Chemical abundances in Galactic planetary nebulae …
We present mid-infrared Spitzer spectra of eleven planetary nebulae in the Galactic Bulge. We derive argon, neon, sulfur, and oxygen abundances for them using mainly infrared line fluxes combined with some optical line fluxes from the…
We surveyed a sample of compact Galactic planetary nebulae (PNe) with the Space Telescope Imaging Spectrograph on the Hubble Space Telescope (HST/STIS) to determine their gas-phase carbon abundances. Carbon abundances in PNe constrain the…
We present the Spitzer/IRS spectra of 157 compact Galactic PNe. These young PNe provide insight on the effects of dust in early post-AGB evolution, before much of the dust is altered or destroyed by the hardening stellar radiation field.…
We study the relation between the chemical composition and the type of dust present in a group of 20 Galactic planetary nebulae (PNe) that have high quality optical and infrared spectra. The optical spectra are used, together with the best…
In this study, we investigate the physical and chemical properties of planetary nebulae (PNe) from the Milky Way Galaxy using the largest number of sources to date, with 1,449 True PNe from the HASH database. Among the Galactic components…
We identify different dust features in our compilation of infrared spectra for 267 planetary nebulae (PNe) from the Spitzer, ISO, and IRAS telescopes. We classify 209 objects according to their dust type: mixed dust (MD), oxygen-rich dust…
A sample of 25 IR-bright planetary nebulae (PNe) towards the Galactic bulge is analysed through 8-13um spectroscopy. The classification of the warm-dust emission features provides a measure of the C/O chemical balance, and represents the…
We present 5 - 40 micron spectroscopy of 41 planetary nebulae (PNe) in the Magellanic Clouds, observed with the Infrared Spectrograph on board the Spitzer Space Telescope. The spectra show the presence of a combination of nebular emission…
We study the chemical abundances of a wide sample of 142 Galactic planetary nebulae (PNe) with good quality observations, for which the abundances have been derived more or less homogeneously, thus allowing a reasonable comparison with…
We investigate the galactic disk distribution of a sample of planetary nebulae characterised in terms of their mid-infrared spectral features. The total number of galactic disk PNe with 8-13mum spectra is brought up to 74 with the inclusion…
We present nucleosynthesis predictions (HeCNOCl) from asymptotic giant branch (AGB) models, with diffusive overshooting from all the convective borders, in the metallicity range Z/4 < Z < 2Zsun. They are compared to recent precise nebular…
We investigate the dual-dust chemistry (DDC) phenomenon in PNe and discuss reasons for its occurrence, by analyzing Spitzer/IRS spectra of a sample of 40 Galactic PNe among which 26 belong to the Galactic Bulge (GB). The mixed chemistry is…
Planetary nebulae (PNe) in the Magellanic Clouds (LMC, SMC) offer a unique opportunity to study both the population and evolution of low- and intermediate-mass stars in an environment which is free of the distance scale bias that hinder…
Our understanding of the chemical evolution of the Galactic bulge requires the determination of abundances in large samples of giant stars and planetary nebulae (PNe). We discuss PNe abundances in the Galactic bulge and compare these…
Low- and intermediate-mass ($\rm 0.8~M_\odot < M < 8~M_\odot$) stars that evolve into planetary nebulae (PNe) play an important role in tracing and driving Galactic chemical evolution. Spectroscopy of PNe enables access to both the initial…
We present an analysis of elemental abundances of He, N, O, Ne, S, and Ar in Magellanic Cloud planetary nebulae (PNe), and focus initially on 14 PNe in the Small Magellanic Cloud (SMC). We derived the abundances from a combination of deep,…
In this, the third of a series of papers, we present well determined chemical abundances for 124 Planetary nebulae (PNe) in the Galactic bulge from deep, long-slit FORS2 spectra from the 8.2 m ESO Very Large telescope (VLT). Prior to this…
We present emission line strengths, abundances, and element ratios (X/O for Ne, S, Cl, and Ar) for a sample of 38 Galactic disk planetary nebulae (PNe) consisting primarily of Peimbert classification Type I. Spectrophotometry for these PNe…
We derive abundances and central star parameters for 15 planetary nebulae (PNe) in M31: 12 in the bulge and 3 in a disk field 14 kpc from the nucleus. No single abundance value characterizes the bulge stars: although the median abundances…
Spitzer MIPS 24 um images were obtained for 36 Galactic planetary nebulae (PNe) whose central stars are hot white dwarfs (WDs) or pre-WDs with effective temperatures of ~100,000 K or higher. Diffuse 24 um emission is detected in 28 of these…