EPJ Web of Conferences 265, 00041 (2022)
https://doi.org/10.1051/epjconf/202226500041

The QUIJOTE¹ line survey of TMC-1

¹ Instituto de Física Fundamental, Dpt. Molecular Astrophysics, CSIC, C/Serrano 121, 28006 Madrid, Spain
² Observatorio Astronómico Nacional, IGN, C/Alfonso XII 3, 28014 Madrid, Spain
³ Observatorio de Yebes, IGN, Cerro de la Palera s/n, 19141 Yebes, Guadalajara, Spain

^* e-mail: jose.cernicharo@csic.es

Published online: 7 September 2022

Abstract

We present the recent results obtained with the QUIJOTE line survey of the cold dark core TMC-1. The observations have been carried out with the YEBES 40m radio telescope (see Figure 1) in the Q-band (31-50 GHz). A new set of receivers have been installed in the telescope within the frame of the ERC synergy Nanocosmos project that allows to cover the whole 31-50 GHz band in dual polarization [1]. The spectral resolution is 38.15 kHz. The sensitivity achieved so far varies between 0.12 and 0.25 mK, and allows to search for new molecules in a line by line (no stacking) detection procedure. These new data have permitted to detect the many relatively small protonated species of abundant molecules and eight sulfur-bearing species. The most exciting result is the detection of hydrocarbon chains and cycles with low permanent dipole moment, such as CH₂CHCCH, CH₂CCHCCH, the propargyl radical (C₃H₃), cyclopentadiene, indene (the first PAH detected in space), ortho-benzyne and two ethynyl derivatives of cyclopentadiene (c-C₅H₅CCH) ([2–7]). We have found that the gas-phase chemistry of hydrocarbons in TMC-1 has to be revisited in depth.