Similar users
Els Peeters
Research Scientist
Institution:
SETI Institute
Summary
Published articles Show More
Characterizing the Infrared Spectra of Small, Neutral, Fully Dehydrogenated Polycyclic Aromatic Hydrocarbons
Published in The Astrophysical Journal
We present the results of a computational study to investigate the infrared spectroscopic properties of a large number of polycyclic aromatic hydrocarbon (PAH) molecules and their fully dehydrogenated counterparts. We constructed a database of fully optimized geometries for PAHs that is complete for eight or fewer fused benzene rings, thus containi...
Carbon-rich dust past the asymptotic giant branch: aliphatics, aromatics, and fullerenes in the Magellanic Clouds
...Published in The Astrophysical Journal
Infrared spectra of carbon-rich objects that have evolved off the asymptotic giant branch reveal a range of dust properties, including fullerenes, polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons, and several unidentified features, including the 21 μm emission feature. To test for the presence of fullerenes, we used the position and ...
The NASA Ames PAH IR Spectroscopic Database Version 2.00: Updated Content, Web Site, and On (Off) line Tools
...Published in The Astrophysical Journal Supplement Series
A significantly updated version of the NASA Ames PAH IR Spectroscopic Database, the first major revision since its release in 2010, is presented. The current version, version 2.00, contains 700 computational and 75 experimental spectra compared, respectively, with 583 and 60 in the initial release. The spectra span the 2.5-4000 μm (4000-2.5 cm-1) r...
Preprints Show More
Spitzer Space Telescope spectra of post-AGB stars in the Large Magellanic Cloud ---polycyclic aromatic hydrocarbons at l...
...
This paper reports variations of polycyclic aromatic hydrocarbons (PAHs) features that were found in Spitzer Space Telescope spectra of carbon-rich post-asymptotic giant branch (post-AGB) stars in the Large Magellanic Cloud (LMC). The paper consists of two parts. The first part describes our Spitzer spectral observing programme of 24 stars includin...
An In-Depth View of the Mid-Infrared Properties of Point Sources and the Diffuse ISM in the SMC Giant HII Region, N66
(abridged)The focus of this work is to study mid-infrared point sources and the diffuse interstellar medium (ISM) in the low-metallicity (~0.2 solar) giant HII region N66 using the Spitzer Space Telescope's Infrared Spectrograph. We study 14 targeted infrared point sources as well as spectra of the diffuse ISM that is representative of both the pho...
The formation of cosmic fullerenes from arophatic clusters
Fullerenes have recently been identified in space and they may play a significant role in the gas and dust budget of various astrophysical objects including planetary nebulae (PNe), reflection nebulae (RNe) and H II regions. The tenuous nature of the gas in these environments precludes the formation of fullerene materials following known vaporizati...
Misc. Show More
Interstellar and circumstellar fullerenes
Fullerenes are a particularly stable class of carbon molecules in the shape of a hollow sphere or ellipsoid that might be formed in the outflows of carbon stars. Once injected into the interstellar medium (ISM), these stable species survive and are thus likely to be widespread in the Galaxy where they contribute to interstellar extinction, heating ...
The nature of circumstellar hydrocarbons
...
Infrared spectroscopy of carbon-rich objects past the asymptotic giant branch reveals a rich variety of dust, including fullerenes, polycyclic aromatic hydrocarbons (PAHs), aliphatic hydrocarbons, the unknown carrier of the 21 µm feature, and the 26–30 µm feature which may arise from MgS. Many of the spectra also show a strong 11 µm feature due pri...
The Circle of Dust: From Nanoparticles to Macromolecules and Beyond
There is increasing observational evidence that a non-negligible fraction of the cosmic carbon is locked up into macromolecules and nanoparticles. Carbonaceous nanoparticles and Hydrogenated Amorphous Carbon (HAC) nanoparticles represent one of the main components of interstellar dust. HAC nanoparticles have been proposed as a viable carrier for th...
