Related papers: Synthetic spectra of UIBs (2 to 40 mu)
Published interpretations of the relative intensity variations of the Unidentified Infrared Bands (UIBs) and their underlying continuum are discussed. An alternative model is proposed, in which a single carrier for both emits a) mostly a…
The present work purports to identify candidate carriers of the UIBs. This requires a procedure for the computation of the emission spectrum of any given candidate. The procedure used here consists in exciting the carrier into a state of…
The current assignments of the 11.3 feature are shown to be incompatible with observations. An unbiased survey of correlation charts suggests that the olefinic group R2=CH2 is a good alternative candidate. For the 12.7 feature, the best…
We present Infrared Space Observatory (ISO) spectra of fourteen isolated Herbig Ae/Be (HAEBE) stars, to study the characteristics of their circumstellar dust. These spectra show large star-to-star differences, in the emission features of…
By applying quantum chemical calculation, interstellar infrared spectrum was categorized to three classes. Type-A show unusual feature of strong peaks at 11.3,12.9, and 14.0 micrometer. Usually observed 6.2, 7.7, and 8.6 micrometer bands…
Interstellar dust shows ubiquitous interstellar infrared spectrum (IR) due to polycyclic aromatic hydrocarbon (PAH). By our previous quantum chemistry calculation, it was suggested that a molecule group having hydrocarbon pentagon-hexagon…
The observed variations in profiles of the interstellar aromatic infrared bands correlate with the object type and are indicative of PAH populations existing i n different sources. Spectroscopic studies on PAHs can provide tools for the int…
A powerful way to observe directly the solid state inventory of dense molecular clouds is by infrared spectroscopy of background stars. We present Spitzer/IRS 5-20 micron spectra of ices toward stars behind the Serpens and Taurus molecular…
We divide some of the observed diffuse interstellar bands (DIBs) into families which appear to have spectral structures of single species. Three different methods are applied to separate such families, exploring the best approach for future…
This study explores the molecular origins of plateaus and continuum underlying IR and FIR bands emitted by compact nebulae, especially proto-planetary nebulae. Computational organic chemistry codes are used to deliver the vibrational…
The spectral region around 10 micrometer, showing prominent dust emission bands, is commonly used to derive the chemical composition of protoplanetary dust. Different analysis methods have been proposed for this purpose, but so far, no…
We report spectra obtained with the Spitzer Space Telescope in the wavelength range between 14 microns and 35 microns of 19 nearby main-sequence stars with infrared excesses. The six stars with strong dust emission show no recognizable…
Infrared spectrum (IR) of Herbig Ae young stars was reproduced and classified by hydrocarbon pentagon-hexagon combined molecules by the quantum chemical calculation. Observed IR list by B. Acke et al. was categorized to four classes. Among…
Protoplanetary disk around a just born young star contains a lot of cosmic dust. especially polycyclic-aromatic-hydrocarbon (PAH), which would become basic component to create biological organics. This study classified many astronomically…
The mid-infrared (IR; 5-15~$\mu$m) spectrum of a wide variety of astronomical objects exhibits a set of broad emission features at 6.2, 7.7, 8.6, 11.3 and 12.7 $\mu$m. About 30 years ago it was proposed that these signatures are due to…
This work reports numerical experiments intended to clarify the internal equilibration process in large molecules, following vibrational excitation. A model of amorphous and oxygenated hydrocarbon macromolecule (about 500 atoms)--simulating…
The recent influx of high-quality infrared spectroscopic data has prompted an extensive reassessment of various laboratory models in comparison with the observed UIBs (Unidentified Infrared Bands). As a result, significant modifications…
The unidentified infrared bands (UIBs) have been observed in virtually every dusty astrophysical environment investigated. The UIB carrier must be abundant and ubiquitous. Strong evidence points to polycyclic aromatic hydrocarbons (PAHs) as…
We present a comprehensive survey of diffuse interstellar bands (DIBs) in $0.91-1.32\mu$m with a newly-developed near-infrared (NIR) spectrograph, WINERED, mounted on the Araki 1.3 m Telescope in Japan. We obtained high-resolution…
Context. Clouds seem unavoidable in cool and dense environments, and hence, are necessary to explain observations of exoplanet atmospheres, most recently of WASP 96b with JWST. Understanding the formation of cloud condensation nuclei in…