arXiv subjects

M. H. Moore

Publications and source records attributed to M. H. Moore.

2 recordsLinked to original sources

arXiv2015

In-situ measurements of the radiation stability of amino acids at 15-140 K

We present new kinetics data on the radiolytic destruction of amino acids measured in situ with infrared spectroscopy. Samples were irradiated at 15, 100, and 140 K with 0.8-MeV protons, and amino-acid decay was followed at each temperature with and without H$_2$O present. Observed radiation products included CO$_2$ and amines, consistent with amino-acid decarboxylation. The half-lives of glycine, alanine, and phenylalanine were estimated for various extraterrestrial environments. Infrared spectral changes demonstrated the conversion from the non-zwitterion structure NH$_2$-CH$_2$(R)-COOH at 15 K to the zwitterion structure $^+$NH$_3$-CH$_2$(R)-COO$^-$ at 140 K for each amino acid studied.

astro-ph.IM↗

arXiv2015

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 near- and mid-infrared optical constants for ethane (C$_2$H$_6$) and ethylene (C$_2$H$_4$) in multiple ice phases and at multiple temperatures. As in our recent work on acetylene (C$_2$H$_2$), we also report new measurements of the index of refraction of each ice at 670 nm. Comparisons are made to earlier work where possible, and electronic versions of our new results are made available.

astro-ph.IM↗