Detection of E-cyanomethanimine towards Sagittarius B2(N) in the Green Bank Telescope PRIMOS Survey

TL;DR

This study reports the first detection of E-cyanomethanimine in space, using the Green Bank Telescope to identify its spectral signatures in Sagittarius B2(N), linking laboratory spectroscopy with astronomical observations.

Contribution

The paper presents the first interstellar detection of E-cyanomethanimine, combining laboratory rotational spectra with GBT survey data to identify this prebiotic molecule in space.

Findings

E-cyanomethanimine detected in Sagittarius B2(N)

Eight rotational transitions observed between 9 and 50 GHz

Link established between laboratory spectra and interstellar signals

Abstract

The detection E-cyanomethanimine (E-HNCHCN) towards Sagittarius B2(N) is made by comparing the publicly available Green Bank Telescope (GBT) PRIMOS survey spectra (Hollis et al.) to laboratory rotational spectra from a reaction product screening experiment. The experiment uses broadband molecular rotational spectroscopy to monitor the reaction products produced in an electric discharge source using a gas mixture of NH3 and CH3CN. Several transition frequency coincidences between the reaction product screening spectra and previously unassigned interstellar rotational transitions in the PRIMOS survey have been assigned to E cyanomethanimine. A total of 8 molecular rotational transitions of this molecule between 9 and 50 GHz are observed with the GBT. E-cyanomethanimine, often called the HCN dimer, is an important molecule in prebiotic chemistry because it is a chemical intermediate in proposed synthetic routes of adenine, one of the two purine nucleobases found in DNA and RNA. New analyses of the rotational spectra of both E-cyanomethanimine and Z-cyanomethanimine that incorporate previous mm-wave measurements are also reported.