Gas phase Elemental abundances in Molecular cloudS (GEMS): I. The prototypical dark cloud TMC 1.

Autor:	Fuente A; Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain., Navarro DG; Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain., Caselli P; Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany., Gerin M; Observatoire de Paris, PSL Research University, CNRS, École Normale Supérieure, Sorbonne Universités, UPMC Univ. Paris 06, 75005, Paris, France., Kramer C; Instituto Radioastronomía Milimétrica (IRAM), Av. Divina Pastora 7, Nucleo Central, 18012, Granada, Spain., Roueff E; Sorbonne Université, Observatoire de Paris, Université PSL, CNRS, LERMA, F-92190, Meudon, France., Alonso-Albi T; Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain., Bachiller R; Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain., Cazaux S; Faculty of Aerospace Engineering, Delft University of Technology, Delft, The Netherlands ; University of Leiden, P.O. Box 9513, NL, 2300 RA, Leiden, The Netherlands., Commercon B; École Normale Supérieure de Lyon, CRAL, UMR CNRS 5574, Université Lyon I, 46 Allée d'Italie, 69364, Lyon Cedex 07, France., Friesen R; National Radio Astronomy Observatory, 520 Edgemont Rd., Charlottesville VA USA 22901., García-Burillo S; Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain., Giuliano BM; Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany., Goicoechea JR; Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain., Gratier P; Laboratoire d'astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615, Pessac, France., Hacar A; Leiden Observatory, Leiden University, PO Box 9513, 2300-RA, Leiden, The Netherlands., Jiménez-Serra I; Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain., Kirk J; Department of Physics, University of Warwick, Coventry CV4 7AL, UK., Lattanzi V; Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany., Loison JC; Institut des Sciences Moléculaires (ISM), CNRS, Univ. Bordeaux, 351 cours de la Libération, F-33400, Talence, France., Malinen J; Department of Physics, University of Helsinki, PO Box 64, 00014, Helsinki, Finland.; Institute of Physics I, University of Cologne, Cologne, Germany., Marcelino N; Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain., Martín-Doménech R; Harvard-Smithsonian Center for Astrophysics, Cambridge, MA 02138, USA., Muñoz-Caro G; Centro de Astrobiología (CSIC-INTA), Ctra. de Ajalvir, km 4, Torrejón de Ardoz, 28850, Madrid, Spain., Pineda J; Centre for Astrochemical Studies, Max-Planck-Institute for Extraterrestrial Physics, Giessenbachstrasse 1, 85748, Garching, Germany., Tafalla M; Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain., Tercero B; Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain., Ward-Thompson D; Jeremiah Horrocks Institute, University of Central Lancashire, Preston PR1 2HE, UK., Treviño-Morales SP; Chalmers University of Technology, Department of Space, Earth and Environment, SE-412 93 Gothenburg, Sweden., Riviére-Marichalar P; Observatorio Astronómico Nacional (OAN), Alfonso XII, 3, 28014, Madrid, Spain., Roncero O; Instituto de Física Fundamental (CSIC), Calle Serrano 123, 28006, Madrid, Spain., Vidal T; Laboratoire d'astrophysique de Bordeaux, Univ. Bordeaux, CNRS, B18N, allée Geoffroy Saint-Hilaire, 33615, Pessac, France., Ballester MY; Departamento de Física, Universidade Federal de Juiz de Fora-UFJF, Juiz de Fora, MG 36036-330, Brazil.
Jazyk:	angličtina
Zdroj:	Astronomy and astrophysics [Astron Astrophys] 2019 May 17; Vol. 624. Date of Electronic Publication: 2019 Apr 19.
DOI:	10.1051/0004-6361/201834654
Abstrakt:	GEMS is an IRAM 30m Large Program whose aim is determining the elemental depletions and the ionization fraction in a set of prototypical star-forming regions. This paper presents the first results from the prototypical dark cloud TMC 1. Extensive millimeter observations have been carried out with the IRAM 30m telescope (3 mm and 2 mm) and the 40m Yebes telescope (1.3 cm and 7 mm) to determine the fractional abundances of CO, HCO + , HCN, CS, SO, HCS + , and N 2 H + in three cuts which intersect the dense filament at the well-known positions TMC 1-CP, TMC 1-NH3, and TMC 1-C, covering a visual extinction range from A V ~ 3 to ~20 mag. Two phases with differentiated chemistry can be distinguished: i) the translucent envelope with molecular hydrogen densities of 1-5×10 3 cm -3 ; and ii) the dense phase, located at A V > 10 mag, with molecular hydrogen densities >10 4 cm -3 . Observations and modeling show that the gas phase abundances of C and O progressively decrease along the C + /C/CO transition zone (A V ~ 3 mag) where C/H ~ 8×10 -5 and C/O~0.8-1, until the beginning of the dense phase at A V ~ 10 mag. This is consistent with the grain temperatures being below the CO evaporation temperature in this region. In the case of sulfur, a strong depletion should occur before the translucent phase where we estimate a S/H ~ (0.4 - 2.2) ×10 -6 , an abundance ~7-40 times lower than the solar value. A second strong depletion must be present during the formation of the thick icy mantles to achieve the values of S/H measured in the dense cold cores (S/H ~8×10 -8 ). Based on our chemical modeling, we constrain the value of ζ H 2 to ~ (0.5 - 1.8) ×10 -16 s -1 in the translucent cloud.
Databáze:	MEDLINE
Externí odkaz:	Zobrazit plný text záznamu