Discovery of the propargyl radical (CH₂CCH) in TMC-1: one of the most abundant radicals ever found and a key species for cyclization to benzene in cold dark clouds.

ABSTRACT: We present the first identification in interstellar space of the propargyl radical (CH₂CCH). This species was observed in the cold dark cloud TMC-1 using the Yebes 40m telescope. The six strongest hyperfine components of the 2_0,2-1_0,1 rotational transition, lying at 37.46 GHz, were detected with signal-to-noise ratios in the range 4.6-12.3 σ. We derive a column density of 8.7 × 10¹³ cm^-2 for CH₂CCH, which translates to a fractional abundance relative to H₂ of 8.7 × 10^-9. This radical has a similar abundance to methyl acetylene, with an abundance ratio CH₂CCH/CH₃CCH close to one. The propargyl radical is thus one of the most abundant radicals detected in TMC-1, and it is probably th

SUBMITTER: Agundez M 

PROVIDER: S-EPMC7610583 | biostudies-literature | 2021 Mar

REPOSITORIES: biostudies-literature