Astrophysics, abstract
astro-ph/0601399

From: Joel Thorarinson [view email]

Date: Wed, 18 Jan 2006 20:45:57 GMT (12kb)

Prebiotic Homochirality as a Critical Phenomenon

Authors: Marcelo Gleiser, Joel Thorarinson

Comments: 6 Pages, 1 Figure, In Press: Origins of Life and Evolution of Biospheres

The development of prebiotic homochirality on early-Earth or another planetary platform may be viewed as a critical phenomenon. It is shown, in the context of spatio-temporal polymerization reaction networks, that environmental effects -- be them temperature surges or other external disruptions -- may destroy any net chirality previously produced. In order to understand the emergence of prebiotic homochirality it is important to model the coupling of polymerization reaction networks to different planetary environments.

http://arxiv.org/abs/astro-ph/0601399

Astrophysics, abstract
astro-ph/0601381

From: Laura Schaefer [view email]

Date: Tue, 17 Jan 2006 23:44:48 GMT (318kb)

Chemistry of Low Mass Substellar Objects

Authors: Katharina Lodders, Bruce Fegley, Jr

Comments: review article: 30 pages, 3 figures, 2 tables; Astrophysics Update v. 2 (in press)

"Brown dwarfs" is the collective name for objects more massive than giant planets such as Jupiter but less massive than M dwarf stars. This review gives a brief description of the classification and chemistry of low mass dwarfs. The current spectral classification of stars includes L and T dwarfs that encompass the coolest known stars and substellar objects. The relatively low atmospheric temperatures and high total pressures in substellar dwarfs lead to molecular gas and condensate chemistry. The chemistry of elements such as C, N, O, Ti, V, Fe, Cr, and the alkali elements play a dominant role in shaping the optical and infrared spectra of the "failed" stars. Chemical diagnostics for the subclassifications are described.

http://arxiv.org/abs/astro-ph/0601381