An analysis of a preliminary ALMA Orion KL spectrum via the use of complete experimental spectra from the laboratory

• Published in: Journal of molecular spectroscopy 2012-10, Vol.280, p.11-20
• Main Authors: Fortman, Sarah M., McMillan, James P., Neese, Christopher F., Randall, Suzanna K., Remijan, Anthony J., Wilson, T.L., De Lucia, Frank C.
• Format: Article
• Language: English
• Subjects: ALMA; Astrophysics; Millimeter; Rotational; Submillimeter
• ISSN: 0022-2852; 1096-083X
• DOI: 10.1016/j.jms.2012.08.002

[Display omitted] ► Preliminary ALMA data is compared with complete experimental spectra. ► Simple models are used to simulate astronomical lineshapes with success. ► Straightforward extensions exist to improve the comparison. Preliminary Atacama Large Millimeter/Submillimeter Array (ALMA) science verification data for a single pixel centered on the hot core of Orion KL (R. A.=05h 35m 14.35s, Dec=−05°22′35″ (J2000)) are available as this special issue on broadband spectroscopy is coming to press. As part of this verification process it is useful to compare simulations based on laboratory spectroscopy with ALMA results. This provides not only a test of instrumentation and analysis, but also a test of astrophysical assumptions such as local thermodynamic equilibrium (LTE) and the temperature variations within telescope beams. However, these tests are spectroscopically limited because it is well known that astrophysical spectra contain large numbers of unknown lines, many of which are presumably due to unanalyzed rotational spectra in excited vibrational states of a relatively few molecules. To address this issue we have previously discussed the use of broadband complete experimental spectra (CES) that is obtained from the analysis of several hundred intensity calibrated spectra taken over a range of temperatures. In this paper we will compare these CES with the similarly complete astrophysical spectra.