Gas properties in the Early Universe deciphered from spectral line surveys of high-z objects: The Cloverleaf Quasar
1 Institut de RadioAstronomie Millimétrique, 300 rue de la piscine, 38240 St. Martin d’Hères, France
2 Department of Space, Earth and Environment, Chalmers University of Technology, Onsala Space Observatory, 439 92 Onsala, Sweden
3 Observatorio Astronomico de Yebes, IGN, Cerro de la Palera, Guadalajara, Spain
4 Instituto de Fisica Fundamental, CSIC, Serrano 121, Madrid, Spain
* e-mail: firstname.lastname@example.org
Published online: 7 September 2022
Molecular lines observed in remote quasars arise from exceptionnally strong starburst regions in the vicinity of the QSO. Their study offers a unique opportunity to probe the gas physical and chemical properties at the epoch of peak star formation (z=2-3). We report the preliminary results of an on-going mm/sub-mm spectral line survey of the Cloverleaf Quasar (z=2.6), the archetype of gravitationally lensed quasars. We identify 14 molecular species, including rare isotopologues of CO and HCO+. The high gas density tracers HCO+, HCN, HNC and CN are detected through several rotational transitions, up to J=8-7 (Eup/k ≃ 155 K). Their emission appears to arise from dense (> 106 cm−3) gas clumps embedded in a circumnuclear disk with a flat rotation curve.
© The Authors, Published by EDP Sciences, 2022
This is an Open Access article distributed under the terms of the Creative Commons Attribution License 4.0 (http://creativecommons.org/licenses/by/4.0/).