Detection of two interstellar polycyclic aromatic hydrocarbons via spectral matched filtering

Brett A McGuire; Ryan A Loomis; Andrew M Burkhardt; Kin Long Kelvin Lee; Christopher N Shingledecker; Steven B Charnley; Ilsa R Cooke; Martin A Cordiner; Eric Herbst; Sergei Kalenskii; Mark A Siebert; Eric R Willis; Ci Xue; Anthony J Remijan; Michael C McCarthy

doi:10.1126/science.abb7535

Detection of two interstellar polycyclic aromatic hydrocarbons via spectral matched filtering

Science. 2021 Mar 19;371(6535):1265-1269. doi: 10.1126/science.abb7535.

Authors

Brett A McGuire^{1

2

3}, Ryan A Loomis^#², Andrew M Burkhardt^#³, Kin Long Kelvin Lee^{4

3}, Christopher N Shingledecker^{5

6

7}, Steven B Charnley⁸, Ilsa R Cooke⁹, Martin A Cordiner^{8

10}, Eric Herbst^{11

12}, Sergei Kalenskii¹³, Mark A Siebert¹², Eric R Willis¹¹, Ci Xue¹¹, Anthony J Remijan², Michael C McCarthy³

Affiliations

¹ Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA. [email protected].
² National Radio Astronomy Observatory, Charlottesville, VA 22903, USA.
³ Center for Astrophysics, Harvard & Smithsonian, Cambridge, MA 02138, USA.
⁴ Department of Chemistry, Massachusetts Institute of Technology, Cambridge, MA 02139, USA.
⁵ Department of Physics and Astronomy, Benedictine College, Atchison, KS 66002, USA.
⁶ Center for Astrochemical Studies, Max Planck Institute for Extraterrestrial Physics, Garching, Germany.
⁷ Institute for Theoretical Chemistry, University of Stuttgart, Stuttgart, Germany.
⁸ Astrochemistry Laboratory and the Goddard Center for Astrobiology, NASA Goddard Space Flight Center, Greenbelt, MD 20771, USA.
⁹ Université de Rennes, Centre National de la Recherche Scientifique, Institut de Physique de Rennes, Unité Mixte de Recherche 6251, F-35000 Rennes, France.
¹⁰ Institute for Astrophysics and Computational Sciences, Department of Physics, Catholic University of America, Washington, DC 20064, USA.
¹¹ Department of Chemistry, University of Virginia, Charlottesville, VA 22904, USA.
¹² Department of Astronomy, University of Virginia, Charlottesville, VA 22904, USA.
¹³ Astro Space Center, Lebedev Physical Institute, Russian Academy of Sciences, Moscow, Russia.

^# Contributed equally.

PMID: 33737489
DOI: 10.1126/science.abb7535

Abstract

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.

Publication types

Research Support, Non-U.S. Gov't