Rotational Spectrum and First Interstellar Detection of 2-methoxyethanol Using ALMA Observations of NGC 6334I
Name
Fried_2024_ApJL_965_L23.pdf
Description
Published version
Size
1.21 MB
Format
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Checksum (MD5)
4faf05327d4e91bd93ab089eca7b4485
Author(s)
Fried, Zachary TP
El-Abd, Samer J
Hays, Brian M
Wenzel, Gabi
Byrne, Alex N
Margulès, Laurent
Motiyenko, Roman A
Shipman, Steven T
Horne, Maria P
Jørgensen, Jes K
Date Issued
April 12, 2024
Journal
The Astrophysical Journal Letters
Publisher
American Astronomical Society
Citation
Zachary T. P. Fried et al 2024 ApJL 965 L23
Version
Final published version
Abstract
We use both chirped-pulse Fourier transform and frequency-modulated absorption spectroscopy to study the rotational spectrum of 2-methoxyethanol (CH3OCH2CH2OH) in several frequency regions ranging from 8.7 to 500 GHz. The resulting rotational parameters permitted a search for this molecule in Atacama Large Millimeter/submillimeter Array (ALMA) observations toward the massive protocluster NGC 6334I, as well as source B of the low-mass protostellar system IRAS 16293−2422. A total of 25 rotational transitions are observed in the ALMA Band 4 data toward NGC 6334I, resulting in the first interstellar detection of 2-methoxyethanol. A column density of 1.3+1.4-.09 x 10 17 cm−2 is derived at an excitation temperature of 143+39
-31 K. However, molecular signal is not observed in the Band 7 data toward IRAS 16293−2422B, and an upper-limit column density of 2.5 × 1015 cm−2 is determined. Various possible formation pathways—including radical recombination and insertion reactions—are discussed. We also investigate physical differences between the two interstellar sources that could result in the observed abundance variations.
MIT Department
Massachusetts Institute of Technology. Department of Chemistry
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Creative Commons Attribution
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DOI of Published Version
https://doi.org/10.3847/2041-8213/ad37ff
