English (United Kingdom)

https://curated-unify.zendy.io/wp-json/zendy-region/v1/featured_content/oa?rat=en

https://curated-unify.zendy.io/wp-json/zendy-region/v1/highlighted_journal/

Global: Zendy Plus annual

Presents the access of premium content as premium feature

Premium Content

Presents the keyphrase highlighting as premium feature

Keyphrase Highlighting

Presents the summarisation as premium feature

Summarisation

Insights

Presents the pdf analysis as premium feature

PDF Analysis

Presents the zaia usage as premium feature

ZAIA

Global: Zendy Tools annual

Global: Zendy Free Plan

Global: Zendy Tools monthly

Global: Zendy Plus monthly

We study the dust present in 56 Galactic planetary nebulae (PNe) throughtheir iron depletion factors, their C/O abundance ratios (in 51 objects), andthe dust features that appear in their infrared spectra (for 33 objects). Oursample objects have deep optical spectra of good quality, and most of them alsohave ultraviolet observations. We use these observations to derive the ironabundances and the C/O abundance ratios in a homogeneous way for all theobjects. We compile detections of infrared dust features from the literatureand we analyze the available Spitzer/IRS spectra. Most of the PNe have C/Oratios below one and show crystalline silicates in their infrared spectra. ThePNe with silicates have C/O < 1, with the exception of Cn 1-5. Most of the PNewith dust features related to C-rich environments (SiC or the 30 {\mu}m featureusually associated to MgS) have C/O $\gtrsim$ 0.8. PAHs are detected over thefull range of C/O values, including 6 objects that also show silicates. Ironabundances are low in all the objects, implying that more than 90% of theiriron atoms are deposited into dust grains. The range of iron depletions in thesample covers about two orders of magnitude, and we find that the highestdepletion factors are found in C-rich objects with SiC or the 30 {\mu}m featurein their infrared spectra, whereas some of the O-rich objects with silicatesshow the lowest depletion factors.

C/O abundance ratios, iron depletions, and infrared dust features in Galactic planetary nebulae