• DOI:10.1126/science.abb7535
• Corpus ID: 232269920

Detection of two interstellar polycyclic aromatic hydrocarbons via spectral matched filtering

@article{McGuire2021DetectionOT,
  title={Detection of two interstellar polycyclic aromatic hydrocarbons via spectral matched filtering},
  author={Brett A. McGuire and Ryan A. Loomis and Andrew M. Burkhardt and Kin Long Kelvin Lee and Christopher N. Shingledecker and Steven B. Charnley and Ilsa R. Cooke and Martin A. Cordiner and Eric Herbst and Sergei Kalenskii and Mark A. Siebert and Eric R. Willis and Ci Xue and Anthony J. Remijan and Michael C. McCarthy},
  journal={Science},
  year={2021},
  volume={371},
  pages={1265 - 1269}
}

• B. McGuire, R. Loomis, +12 authors M. McCarthy
• Published 18 March 2021
• Physics
• Science

Identifying PAHs in space Midinfrared spectroscopy has shown that polycyclic aromatic hydrocarbons (PAHs) are abundant in many astronomical objects, but this technique cannot determine which specific PAH molecules are present. Radio astronomy could provide individual identifications if the molecule is sufficiently abundant and has a large dipole moment, but PAHs are expected to produce large numbers of very weak lines. McGuire et al. performed a stacking and matched filter analysis to search for PAHs in radio observations of TMC-1, located within the interstellar Taurus Molecular Cloud. They identified emission from two isomers of the small PAH cyanonapthalene, two fused benzene rings with a CN group attached. Science, this issue p. 1265 Radio astronomy is used to identify specific polycyclic aromatic hydrocarbon molecules in the interstellar medium. Unidentified infrared emission bands are ubiquitous in many astronomical sources. These bands are widely, if not unanimously, attributed to collective emissions from polycyclic aromatic hydrocarbon (PAH) molecules, yet no single species of this class has been identified in space. Using spectral matched filtering of radio data from the Green Bank Telescope, we detected two nitrile-group–functionalized PAHs, 1- and 2-cyanonaphthalene, in the interstellar medium. Both bicyclic ring molecules were observed in the TMC-1 molecular cloud. In this paper, we discuss potential in situ gas-phase PAH formation pathways from smaller organic precursor molecules.