Related papers: Iron Depletion into Dust Grains in Galactic Planet…
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 here preliminary results of an analysis of the iron abundance in the ionized gas of three planetary nebulae and one H II region of the Large Magellanic Cloud (LMC). These results are compared with the ones we obtain for a sample…
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…
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 explore the elemental abundances in Galactic planetary nebulae (PNe) compared with those of their stellar progenitors (Red Giant Branch and Asymptotic Giant Branch, RGB and AGB, stars), to explore and quantify the expected -- i.e., due…
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 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 have performed a statistical analysis using broad band IRAS data on about 500 planetary nebulae with the aim of characterizing their dust content. Our approach is different from previous studies in that it uses an extensive grid of…
The origin and depletion of iron differ from all other abundant refractory elements that make up the composition of the interstellar dust. Iron is primarily synthesized in Type Ia supernovae (SNe Ia) and in core collapse supernovae (CCSN),…
We consider the depletion of elements from the interstellar gas onto a population of very small dust grains. Adopting a grain model in which of order 4% of the cosmic C abundance is in grains with radii <= 10 Angstroms, we find that the…
A study of gas-phase element abundances reported in the literature for 17 different elements sampled over 243 sight lines in the local part of our Galaxy reveals that the depletions into solid form (dust grains) are extremely well…
A broad array of interstellar absorption features that appear in the ultraviolet spectra of bright sources allows us to measure the abundances and ionization states of many important heavy elements that exist as free atoms in the…
Dust and associated depletion of heavy elements from the gas phase can modify the thermal properties of HII regions from the dust-free case, with significant consequences for the emergent optical spectrum. We present the results of…
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…
In this work we report spectrophotometric observations of a planetary nebula sample towards the galactic bulge. A total of 45 PNe was observed and their physical parameters (electron density and temperature) were derived. Ionic abundances…
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 have searched for the emission from \fex and \fexiv that is expected from the gas emitting in diffuse X-rays in \bd, NGC 6543, NGC 7009, and NGC 7027. Neither line was detected in any object. Models that fit the X-ray spectra of these…
The depletion of elements onto dust grains is characterized using a generalized depletion strength $F_*$ for any sightline, and trend-line parameters $A_X, B_X$ and $z_X$. The parameters $A_X, B_X$ and $z_X$ define the relative depletion…
We present a novel method to characterize dust depletion, namely, the depletion of metals into dust grains. We used observed correlations among relative abundances combining a total of 17 metals in diverse galactic environments, including…
We study metal depletion due to dust in the interstellar medium (ISM) to infer the properties of dust grains and characterize the metal and dust content of galaxies, down to low metallicity and intermediate redshift z. We provide metal…