THE search for a complex molecule in a selected hot core region: A rigorous attempt to confirm trans-ethyl methyl ether toward w51 e1/e2

P. Brandon Carroll, Brett A. McGuire, Geoffrey A. Blake, A. J. Apponi, Lucy M Ziurys, Anthony Remijan

Research output: Contribution to journalArticle

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Abstract

An extensive search has been conducted to confirm transitions of trans-ethyl methyl ether (tEME, C2H5OCH3), toward the high-mass star forming region W51 e1/e2 using the 12 m Telescope of the Arizona Radio Observatory at wavelengths from 2 mm and 3 mm. In short, we cannot confirm the detection of tEME toward W51 e1/e2 and our results call into question the initial identification of this species by Fuchs et al. Additionally, re-evaluation of the data from the original detection indicates that tEME is not present toward W51 e1/e2 in the abundance reported by Fuchs and colleagues. Typical peak-to-peak noise levels for the present observations of W51 e1/e2 were between 10 and 30 mK, yielding an upper limit of the tEME column density of ≤1.5 × 1015 cm-2. This would make tEME at least a factor of two times less abundant than dimethyl ether (CH3OCH3) toward W51 e1/e2. We also performed an extensive search for this species toward the high-mass star forming region Sgr B2(N-LMH) with the National Radio Astronomy Observatory 100 m Green Bank Telescope. No transitions of tEME were detected and we were able to set an upper limit to the tEME column density of ≤4 × 1014 cm-2 toward this source. Thus, we are able to show that tEME is not a new molecular component of the interstellar medium and that an exacting assessment must be carried out when assigning transitions of new molecular species to astronomical spectra to support the identification of large organic interstellar molecules.

Original languageEnglish (US)
Article number15
JournalAstrophysical Journal
Volume799
Issue number1
DOIs
StatePublished - Jan 20 2015

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ether
ethers
observatories
observatory
telescopes
radio
molecules
stars
radio astronomy
astronomy
wavelength
evaluation
wavelengths
detection
noise level

Keywords

  • astrochemistry
  • ISM: clouds
  • ISM: individual objects (W51 e1/e2, Sagittarius B2(N))
  • ISM: molecules

ASJC Scopus subject areas

  • Space and Planetary Science
  • Astronomy and Astrophysics

Cite this

THE search for a complex molecule in a selected hot core region : A rigorous attempt to confirm trans-ethyl methyl ether toward w51 e1/e2. / Carroll, P. Brandon; McGuire, Brett A.; Blake, Geoffrey A.; Apponi, A. J.; Ziurys, Lucy M; Remijan, Anthony.

In: Astrophysical Journal, Vol. 799, No. 1, 15, 20.01.2015.

Research output: Contribution to journalArticle

Carroll, P. Brandon ; McGuire, Brett A. ; Blake, Geoffrey A. ; Apponi, A. J. ; Ziurys, Lucy M ; Remijan, Anthony. / THE search for a complex molecule in a selected hot core region : A rigorous attempt to confirm trans-ethyl methyl ether toward w51 e1/e2. In: Astrophysical Journal. 2015 ; Vol. 799, No. 1.
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