CHEMICAL SIMULATIONS OF PREBIOTIC MOLECULES: INTERSTELLAR ETHANIMINE ISOMERS

Journal Article · Mon Jun 20 04:00:00 EDT 2016 · Astrophysical Journal

DOI:https://doi.org/10.3847/0004-637X/824/2/129· OSTI ID:22666156

Quan, Donghui; Durr, Allison ^[1]; Herbst, Eric ^[2]; Corby, Joanna F. ^[3]; Hassel, George ^[4]

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1. Department of Chemistry, Eastern Kentucky University, Richmond, KY 40475 (United States)
2. Departments of Chemistry and Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)
3. Department of Astronomy, University of Virginia, Charlottesville, VA 22904 (United States)
4. Physics and Astronomy Department, Siena College, Loudonville, NY 12211 (United States)

The E- and Z- isomers of ethanimine (CH{sub 3}CHNH) were recently detected toward the star-forming region Sagittarius (Sgr) B2(N) using the Green Bank Telescope PRIMOS cm-wave spectral data, and imaged by the Australia Telescope Compact Array. Ethanimine is not reported in the hot cores of Sgr B2, but only in gas that absorbs at +64 and +82 km s{sup −1} in the foreground of continuum emission generated by H ii regions. The ethanimine isomers can serve as precursors of the amino acid alanine and may play important roles in forming biological molecules in the interstellar medium. Here we present a study of the chemistry of ethanimine using a gas-grain simulation based on rate equations, with both isothermal and warm-up conditions. In addition, the density, kinetic temperature, and cosmic ray ionization rate have been varied. For a variety of physical conditions in the warm-up models for Sgr B2(N) and environs, the simulations show reasonable agreement with observationally obtained abundances. Isothermal models of translucent clouds along the same line of sight yield much lower abundances, so that ethanimine would be much more difficult to detect in these sources despite the fact that other complex molecules have been detected there.

• OSTI ID: 22666156
• Journal Information: Astrophysical Journal, Journal Name: Astrophysical Journal Journal Issue: 2 Vol. 824; ISSN ASJOAB; ISSN 0004-637X
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
ABUNDANCE
ALANINES
CLOUDS
COSMIC RADIATION
DENSITY
EMISSION
IONIZATION
MOLECULES
PRECURSOR
REACTION KINETICS
SIMULATION
STARS
TELESCOPES