S.N.Bose National Centre for Basic Sciences >
Library >
Publications >
2012 >

Please use this identifier to cite or link to this item: http://hdl.handle.net/123456789/457

Title: Hydro-chemical study of the evolution of interstellar pre-biotic molecules during the collapse of molecular clouds
Authors: Majumdar, Liton
Das, Ankan
Chakrabarti, Sandip K
Chakrabarti, Sonali
Keywords: ISM: clouds
stars: formation
Issue Date: 2012
Publisher: Res. Astron. Astrophys.
Citation: L. Majumdar, A. Das, S. K. Chakrabarti, and S. Chakrabarti, Hydro-chemical study of the evolution of interstellar pre-biotic molecules during the collapse of molecular clouds, Res. Astron. Astrophys., 2012, 12, 1613
Abstract: One of the stumbling blocks for studying the evolution of interstellar molecules is the lack of adequate knowledge about the rate coefficients of various reactions which take place in the interstellar medium and molecular clouds. Some theoretical models of rate coefficients do exist in the literature for computing abundances of complex pre-biotic molecules. So far these have been used to study the abundances of these molecules in space. However, in order to obtain more accurate final compositions in these media, we have calculated the rate coefficients for the formation of some of the most important interstellar pre-biotic molecules by using quantum chemical theory.We use these rates inside our hydro-chemical model to examine the chemical evolution and final abundances of pre-biotic species during the collapsing phase of a proto-star.We find that a significant amount of various pre-biotic molecules could be produced during the collapse phase of a proto-star. We thoroughly study the formation of these molecules via successive neutral-neutral and radical-radical/radicalmolecular reactions. We present the time evolution of the chemical species with an emphasis on how the production of these molecules varies with the depth of a cloud. We compare the formation of adenine in interstellar space using our rate-coefficients and using those obtained from existing theoretical models. Formation routes of the pre-biotic molecules are found to be highly dependent on the abundances of the reactive species and the rate coefficients involved in the reactions. The presence of grains strongly affects the abundances of the gas phase species. We also carry out a comparative study between different pathways available for the synthesis of adenine, alanine, glycine and other molecules considered in our network. Despite the huge abundances of the neutral reactive species, production of adenine is found to be strongly dominated by the radical-radical/radical-molecular reaction pathways. If all the reactions considered here contribute to the production of alanine and glycine, then neutral-neutral and radical-radical/radical-molecular pathways are both found to have a significant part in the production of alanine. Moreover, radical-radical/radical-molecular pathways also play a major role in the production of glycine.
URI: http://hdl.handle.net/123456789/457
Appears in Collections:2012

Files in This Item:

File Description SizeFormat
Hydro-chemical study of the evolution of.pdf334.48 kBAdobe PDFView/Open

Items in DSpace are protected by copyright, with all rights reserved, unless otherwise indicated.


Valid XHTML 1.0! DSpace Software Copyright © 2002-2010  Duraspace - Feedback