Astronomy & Astrophysics manuscript no. CKVulMoleculesALMA_v0 c ESO 2020 June 19, 2020 Molecular remnant of Nova 1670 (CK Vulpeculae) I. Properties of the gas and its enigmatic origin Tomek Kaminski´ 1; 2, Karl M. Menten3, Romuald Tylenda1, Ka Tat Wong (Ã嘉T)3; 4, Arnaud Belloche3, Andrea Mehner5, Mirek R. Schmidt1, and Nimesh A. Patel2 1 Nicolaus Copernicus Astronomical Center, Polish Academy of Sciences, Rabianska´ 8, 87-100 Torun,´ e-mail:
[email protected] 2 Center for Astrophysics j Harvard & Smithsonian , 60 Garden Street, Cambridge, MA 02138 3 Max Planck Institut für Radioastronomie, Auf dem Hügel 69, D-53121 Bonn, Germany 4 Institut de Radioastronomie Millimétrique, 300 rue de la Piscine, 38406 Saint-Martin-d’Hères, France 5 ESO – European Organisation for Astronomical Research in the Southern Hemisphere, Alonso de Cordoba 3107, Vitacura, Santiago, Chile June 19, 2020 ABSTRACT CK Vul erupted in 1670 and is considered a Galactic stellar-merger candidate. Its remnant, observed 350 yr after the eruption, contains a molecular component of surprisingly rich composition, including polyatomic molecules as complex as methylamine (CH3NH2). We present interferometric line surveys with subarcsec resolution with ALMA and SMA. The observations provide interferometric maps of molecular line emission at frequencies between 88 and 243 GHz that allow imaging spectroscopy of more than 180 transitions of 26 species. We present, classify, and analyze the different morphologies of the emission regions displayed by the molecules. We also perform a non-LTE radiative-transfer analysis of emission of most of the observed species, deriving the kinetic temperatures and column densities in five parts of the molecular nebula.