Thumbnail
Access Restriction
Open

Author McMillan, James P. ♦ Fortman, Sarah M. ♦ Neese, Christopher F. ♦ Lucia, Frank C. De
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ATOMIC AND MOLECULAR PHYSICS ♦ ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ ASTROPHYSICS ♦ CATALOGS ♦ FORMATES ♦ GHZ RANGE ♦ INTERSTELLAR SPACE ♦ MOLECULES ♦ QUANTUM MECHANICS ♦ SIMULATION ♦ SPECTRA ♦ TEMPERATURE DEPENDENCE ♦ VIBRATIONAL STATES
Abstract Because methyl formate (HCOOCH{sub 3}) is abundant in the interstellar medium and has a strong, complex spectrum, it is a major contributor to the list of identified astrophysical lines. Because of its spectral complexity, with many low lying torsional and vibrational states, the quantum mechanical (QM) analysis of its laboratory spectrum is challenging and thus incomplete. As a result it is assumed that methyl formate is also one of the major contributors to the lists of unassigned lines in astrophysical spectra. This paper provides a characterization, without the need for QM analysis, of the spectrum of methyl formate between 214.6 and 265.4 GHz for astrophysically significant temperatures. The experimental basis for this characterization is a set of 425 spectra, with absolute intensity calibration, recorded between 248 and 408 K. Analysis of these spectra makes possible the calculation of the Complete Experimental Spectrum of methyl formate as a function of temperature. Of the 7132 strongest lines reported in this paper, 2523 are in the QM catalogs. Intensity differences of 5%–10% from those calculated via QM models were also found. Results are provided in a frequency point-by-point catalog that is well suited for the simulation of overlapped spectra. The common astrophysical line frequency, line strength, and lower state energy catalog is also provided.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2016-05-20
Publisher Place United States
Journal Astrophysical Journal
Volume Number 823
Issue Number 1


Open content in new tab

   Open content in new tab