Laboratory Spectra of 10 K ICEs: A Comparison with Some Astronomical Spectra

Spectra of some new extended corona

For two graphs $mathrm{G}$ and $mathrm{H}$ with $n$ and $m$ vertices, the corona $mathrm{G}circmathrm{H}$ of $mathrm{G}$ and $mathrm{H}$ is the graph obtained by taking one copy of $mathrm{G}$ and $n$ copies of $mathrm{H}$ and then joining the $i^{th}$ vertex of $mathrm{G}$ to every vertex in the $i^{th}$ copy of $mathrm{H}$. The neighborhood corona $mathrm{G}starmathrm{H}$ of $mathrm{G}$ and $...

Laboratory and astronomical IR spectra : an experimental clue for their comparison

It is well known that particle shape and size can have very important effects on the profile of icy absorption features. In fact Mie-scattering calculations show that absorption features can be shifted with respect to laboratory (bulk) spectra of thin films and subpeaks appear. The difference between bulk spectra and small particle extinction spectra depends on the optical constants (n, k) of t...

Infrared spectra and optical constants of astronomical ices: II. Ethane and ethylene

Infrared spectroscopic observations have established the presence of hydrocarbon ices on Pluto and other TNOs, but the abundances of such molecules cannot be deduced without accurate optical constants (n, k) and reference spectra. In this paper we present our recent measurements of nearand mid-infrared optical constants for ethane (C2H6) and ethylene (C2H4) in multiple ice phases and at multipl...

Infrared spectra and optical constants of astronomical ices: I. Amorphous and crystalline acetylene

Atomic and Molecular Aspects of Astronomical Spectra

In the first section of this thesis, we present the atomic part of our investigation. A C atomic target was prepared and used to generate theoretical data required in the investigation of recombination lines that arise from collisions between electrons and ions in thin plasma found in planetary nebulae and other astrophysical objects. The R-matrix method of electron scattering theory was used t...