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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

A search for cyanopolyynes in L1157-B1

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Author(s):
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Mendoza, Edgar [1, 2] ; Lefloch, B. [1, 2] ; Ceccarelli, C. [2] ; Kahane, C. [2] ; Jaber, A. A. [2, 3] ; Podio, L. [4] ; Benedettini, M. [5] ; Codella, C. [4] ; Viti, S. [6] ; Jimenez-Serra, I. [7] ; Lepine, J. R. D. [1] ; Boechat-Roberty, H. M. [8] ; Bachiller, R. [9]
Total Authors: 13
Affiliation:
[1] Univ Sao Paulo, Inst Astron Geofis & Ciencias Atmosfer, BR-05508090 Sao Paulo, SP - Brazil
[2] Univ Grenoble Alpes, CNRS, IPAG, F-38000 Grenoble - France
[3] Univ AL Muthanna, Coll Sci, Phys Dept, Al Muthanna - Iraq
[4] INAF, Osservatorio Astrofis Arcetri, Largo Enrico Fermi 5, I-50125 Florence - Italy
[5] Ist Astrofis & Planetol Spaziali, INAF, Via Fosso Cavaliere 100, I-00133 Rome - Italy
[6] UCL, Dept Phys & Astron, Gower St, London WC1E 6BT - England
[7] Queen Mary Univ London, Sch Phys & Astron, Mile End Rd, London E1 4NS - England
[8] Univ Fed Rio de Janeiro, Observ Valongo, BR-20080090 Rio de Janeiro, RJ - Brazil
[9] Observ Astron Nacl, IGN, Calle Alfonso XII, E-28004 Madrid - Spain
Total Affiliations: 9
Document type: Journal article
Source: Monthly Notices of the Royal Astronomical Society; v. 475, n. 4, p. 5501-5512, APR 2018.
Web of Science Citations: 5
Abstract

We present here a systematic search for cyanopolyynes in the shock region L1157-B1 and its associated protostar L1157-mm in the framework of the Large Program `Astrochemical Surveys At IRAM' (ASAI), dedicated to chemical surveys of solar-type star-forming regions with the IRAM 30-m telescope. Observations of the millimeter windows between 72 and 272 GHz permitted the detection of HC3N and its 13C isotopologues, and HC5N (for the first time in a protostellar shock region). In the shock, the analysis of the line profiles shows that the emission arises from the outflow cavities associated with L1157-B1 and L1157-B2. Molecular abundances and excitation conditions were obtained from the analysis of the Spectral Line Energy Distributions under the assumption of Local Thermodynamical Equilibrium or using a radiative transfer code in the Large Velocity Gradient approximation. Towards L1157 mm, the HC3N emission arises from the cold envelope (T-rot = 10 K) and a higher-excitation region (T-rot = 31 K) of smaller extent around the protostar. We did not find any evidence of C-13 or D fractionation enrichment towards L1157-B1. We obtain a relative abundance ratio HC3N/HC5N of 3.3 in the shocked gas. We find an increase by a factor of 30 of the HC3N abundance between the envelope of L1157-mm and the shock region itself. Altogether, these results are consistent with a scenario in which the bulk of HC3N was produced by means of gas phase reactions in the passage of the shock. This scenario is supported by the predictions of a parametric shock code coupled with the chemical model UCL\_CHEM. (AU)

FAPESP's process: 15/22254-0 - Preparing for LLAMA: astrochemistry of star forming regions i. on the origin of C-chain molecules and deuteration around protostars
Grantee:Edgar Fabián Mendoza Rodríguez
Support type: Scholarships abroad - Research Internship - Post-doctor
FAPESP's process: 14/22095-6 - ACHEMOS: astrochemistry of our origins, a comprehensive study of the prebiotic chemistry in pre-stellar regions
Grantee:Edgar Fabián Mendoza Rodríguez
Support type: Scholarships in Brazil - Post-Doctorate