Diffuse interstellar bands: a comprehensive laboratory study.
As a result of the search for the identity of the chromophores responsible for producing the diffuse interstellar bands, a comprehensive exposition of experimental data is presented, which implicates the following molecules: (1) The extremely stable organic molecules, magnesium tetrabenzoporphyrin (MgTBP) and H(2)TBP. (2) A paraffin matrix (referred to as "grains") containing TBPs. (3) A low concentration of pyridine (also within the grains), whose transmission window at 2175 A, accounts for the ubiquitous UV bump. The blue emission spectra associated with the central star, HD44179, of the Red Rectangle displays the fluorescence excitation spectra of bare MgTBP. This unique spectrum matches the low temperature lab data of MgTBP in the vapor phase. An effective grain temperature of 2.728 K (+/-0.008) was deduced, based on MgTBP's lowest measured vibrational state of 341 GHz.
Johnson
Fred M
FM
Cal State University Fullerton, Department of Physics, Fullerton, CA 92834, USA. drfmjohnson@hotmail.com
D055580:Astronomical Phenomena; D001256:Astronomy; D005118:Extraterrestrial Environment / Q000737:chemistry*; D008274:Magnesium / Q000737:chemistry; D008665:Metalloporphyrins / Q000737:chemistry; D008860:Microscopy, Ultraviolet; D008954:Models, Biological; D011166:Porphyrins / Q000737:chemistry; D016082:Solar System; D013050:Spectrometry, Fluorescence; D013057:Spectrum Analysis
D008665:Metalloporphyrins; D011166:Porphyrins; C518758:dipyridyl magnesium tetrabenzoporphyrin; D008274:Magnesium