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Author Bernstein, L. S. ♦ Cline, J. A. ♦ Clark, F. O. ♦ Lynch, D. K.
Source United States Department of Energy Office of Scientific and Technical Information
Content type Text
Language English
Subject Keyword ASTROPHYSICS, COSMOLOGY AND ASTRONOMY ♦ ATOMS ♦ COMPUTERIZED SIMULATION ♦ EMISSION SPECTRA ♦ GHZ RANGE ♦ INTERSTELLAR SPACE ♦ LIMITING VALUES ♦ MAPPING ♦ MICROWAVE RADIATION ♦ MOLECULES ♦ POLYCYCLIC AROMATIC HYDROCARBONS
Abstract We argue that the observed spectroscopic and statistical properties of the diffuse interstellar band (DIB) carriers are those that are needed to produce the anomalous microwave emission (AME). We explore this idea using a carrier-impartial model for AME based on the observed DIB statistical properties. We show that an observed distribution of profile widths for narrow DIBs can be mapped into an AME spectrum. The mapping model is applied to width distributions observed for HD 204827 and HD 183143, selected because their spectroscopic and statistical properties bracket those for most other sight lines. The predicted AME spectra for these sight lines agree well with the range of spectral shapes, and peak frequencies, ∼23–31 GHz, typically observed for AME. We use the AME spectral profiles to derive a strong constraint between the average carrier size and its rotational temperature. The constraint is applied to a variety of postulated molecular carrier classes, including polycyclic aromatic hydrocarbons, fulleranes, hydrocarbon chains, and amorphous hydrocarbon clusters. The constraint favors small, cold carriers with average sizes of ∼8–15 carbon atoms, and average rotational temperatures of ∼3–10 K, depending on carrier type. We suggest new observations, analyses, and modeling efforts to help resolve the ambiguities with regard to carrier size and class, and to further clarify the DIB–AME relationship.
ISSN 0004637X
Educational Use Research
Learning Resource Type Article
Publisher Date 2015-11-10
Publisher Place United States
Journal Astrophysical Journal
Volume Number 813
Issue Number 2


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