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...
A Sensitive Spectral Survey of Interstellar Features in the Near-UV [3050-3700 Å]
Published in The Astrophysical Journal Supplement Series
We present a comprehensive and sensitive unbiased survey of interstellar features in the near-UV range (3050–3700 Å). We combined a large number of VLT/UVES archival observations of a sample of highly reddened early-type stars—typical diffuse interstellar band targets—and unreddened standards. We stacked the individual observations to obtain a redd...
The Gas-rich Circumbinary Disk of HR 4049. II. A Detailed Study of the Near-infrared Spectrum
Published in The Astrophysical Journal
HR 4049 is a peculiar evolved binary surrounded by a circumbinary disk. Mid- infrared observations show that the disk is rich in molecular gas and radially extended. To study the properties of this disk, we re-analyzed a set of near-infrared observations at high spectral resolution obtained with Gemini-Phoenix. These data cover absorption lines ori...
Preprints Show More
A sensitive spectral survey of interstellar features in the near-UV [3050-3700{\AA}]
We present a comprehensive and sensitive unbiased survey of interstellar features in the near-UV range (3050-3700 {\AA}). We combined a large number of VLT/UVES archival observations of a sample of highly reddened early type stars -- typical diffuse interstellar band (DIB) targets -- and unreddened standards. We stacked the individual observations ...
The Gas-Rich Circumbinary Disk of HR 4049 I: A Detailed Study of the Mid-Infrared Spectrum
We present a detailed analysis of the mid-infrared spectrum of the peculiar evolved object HR 4049. The full Spitzer-IRS high-resolution spectrum shows a wealth of emission with prominent features from CO$_2$ and H$_2$O and possible contributions from HCN and OH. We model the molecular emission and find that it originates from a massive ($M \gtrsim...
Fullerenes in circumstellar and interstellar environments
In recent years, the fullerene species C60 (and to a lesser extent also C70) has been reported in the mid-IR spectra of various astronomical objects. Cosmic fullerenes form in the circumstellar material of evolved stars, and survive in the interstellar medium (ISM). It is not entirely clear how they form or what their excitation mechanism is.
Misc. Show More
The gas-rich disk of HR 4049: A study of the infrared spectrum
Here, we present a summary of our analyses of the mid-and near-infrared spectrum of the unusual evolved binary HR 4049. We f nd that the disk is massive (M> 8× 10− 3 M⊙), warm and radially extended. We also report some enrichment in 17 O and 18 O and a comparison of observations from Spitzer-IRS to those obtained by ISO-SWS 10 years earlier reveals...
Cosmic Fullerenes
In recent years, the fullerene species C60(and to a lesser extent C70) have been detected in a variety of environments-‐-‐from the circumstellar carbon-‐rich surroundings of evolved stars to interstellar reflection nebulae and young stellar objects. Fullerenes are the first and thus far the only large aromatics identified in space. In spite of thes...
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 ...
