相关论文: Iron Depletion in ionized Nebulae of the Large Mag…

We constrain the iron abundance in a sample of 33 low-ionization Galactic planetary nebulae (PNe) using [Fe III] lines and correcting for the contribution of higher ionization states with ionization correction factors (ICFs) that take into…

We present preliminary results of an analysis of the iron depletion factor into dust grains for a sample of 20 planetary nebulae (PNe) from the Galactic bulge. We compare these results with the ones we obtained in a prior analysis of 28…

The iron depletion factors found in Galactic planetary nebulae (PNe) span over two orders of magnitude, suggesting that there are differences in the grain formation and destruction processes from object to object. We explore here the…

Iron suffers from high levels of depletion in the highly ionized environments of planetary nebulae, making the direct determination of undepleted elemental iron abundances difficult. Zinc, which does not suffer from the same depletion…

We perform a homogeneous analysis of the Fe/Ni abundance ratio in eight Galactic planetary nebulae (PNe) and three Galactic H II regions that include the Orion nebula, where we study four nebular zones and one shocked region. We use [Fe…

We use very deep spectra obtained with the Ultraviolet-Visual Echelle Spectrograph at the Very Large Telescope to derive physical conditions and chemical abundances of four H II regions of the Large Magellanic Cloud (LMC) and four H II…

We study the dust present in 56 Galactic planetary nebulae (PNe) through their iron depletion factors, their C/O abundance ratios (in 51 objects), and the dust features that appear in their infrared spectra (for 33 objects). Our sample…

We use very deep spectra obtained with the Ultraviolet-Visual Echelle Spectrograph in the Very Large Telescope in order to determine the physical conditions, the chemical abundances and the iron depletion factors of four H II regions of the…

We present the first attempt to determine the iron abundance in hot central stars of planetary nebulae. We perform an analysis with fully metal-line blanketed NLTE model atmospheres for a sample of ten stars (T_eff >= 70.000 K) for which…

We present a study of the composition of gas and dust in the Large and Small Magellanic Clouds (LMC and SMC, together -- the MCs) as measured by UV absorption spectroscopy. We have measured P II and Fe II along 85 sightlines toward the MCs…

A key component of the baryon cycle in galaxies is the depletion of metals from the gas to the dust phase in the neutral ISM. The METAL (Metal Evolution, Transport and Abundance in the Large Magellanic Cloud) program on the Hubble Space…

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,…

High-resolution HST ultra-violet spectra for five B-type stars in the Magellanic Bridge and in the Large and Small Magellanic Clouds have been analysed to estimate their iron abundances. Those for the Clouds are lower than estimates…

The metallicity and gas density dependence of interstellar depletions, the dust-to-gas (D/G), and dust-to-metal (D/M) ratios have important implications for how accurately we can trace the chemical enrichment of the universe; either by…

The chemical abundances of neon and sulfur for 25 planetary nebulae (PNe) in the Magellanic Clouds are presented. These abundances have been derived using mainly infrared data from the Spitzer Space Telescope. The implications for the…

We summarize recent studies of the predominantly neutral gas in the Magellanic Clouds (MC), based on combinations of high-resolution optical spectra and UV spectra obtained with IUE, HST, and FUSE. Similarities in relative gas-phase…

Available X-ray data are collected and organized concerning the iron and gas content of galaxy clusters and groups, together with the optical luminosity, mass and iron abundance of cluster galaxies. Several astrophysical inferences are then…

We consider a small sample of oxygen-rich, asymptotic giant branch stars in the Large Magellanic Cloud, observed by the Spitzer Space Telescope, exhibiting a peculiar spectral energy distribution, which can be hardly explained by the common…

Metal Evolution, Transport, and Abundance in the LMC (METAL) is a large Cycle 24 program on the Hubble Space Telescope aimed at measuring dust extinction properties and interstellar depletions in the Large Magellanic Cloud (LMC) at…

We present a Spitzer Space Telescope spectroscopic study of a sample of 25 planetary nebulae in the Magellanic Clouds. The low-resolution modules are used to analyze the dust features present in the infrared spectra. This study complements…