Codella, C;
Ceccarelli, C;
Caselli, P;
Balucani, N;
Barone, V;
Fontani, F;
Lefloch, B;
... Yamamoto, S; + view all
(2017)
Seeds of Life in Space (SOLIS) II. Formamide in protostellar shocks: Evidence for gas-phase formation.
Astronomy & Astrophysics
, 605
, Article L3. 10.1051/0004-6361/201731249.
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Abstract
CONTEXT: Modern versions of the Miller-Urey experiment claim that formamide (NH2CHO) could be the starting point for the formation of metabolic and genetic macromolecules. Intriguingly, formamide is indeed observed in regions forming solar-type stars and in external galaxies. Aims. How NH2CHO is formed has been a puzzle for decades: our goal is to contribute to the hotly debated question of whether formamide is mostly formed via gas-phase or grain surface chemistry. METHODS: We used the NOrthern Extended Millimeter Array (NOEMA) interferometer to image NH2CHO towards the L1157-B1 blue-shifted shock, a well-known interstellar laboratory, to study how the components of dust mantles and cores released into the gas phase triggers the formation of formamide. RESULTS: We report the first spatially resolved image (size ~9″, ~2300 AU) of formamide emission in a shocked region around a Sun-like protostar: the line profiles are blueshifted and have a FWHM ≃ 5 km s-1. A column density of NNH2CHO = 8 × 1012 cm-1 and an abundance, with respect to H-nuclei, of 4 × 10-9 are derived. We show a spatial segregation of formamide with respect to other organic species. Our observations, coupled with a chemical modelling analysis, indicate that the formamide observed in L1157-B1 is formed by a gas-phase chemical process and not on grain surfaces as previously suggested. CONCLUSIONS: The Seeds of Life in Space (SOLIS) interferometric observations of formamide provide direct evidence that this potentially crucial brick of life is efficiently formed in the gas phase around Sun-like protostars.
| Type: | Article |
|---|---|
| Title: | Seeds of Life in Space (SOLIS) II. Formamide in protostellar shocks: Evidence for gas-phase formation |
| Open access status: | An open access version is available from UCL Discovery |
| DOI: | 10.1051/0004-6361/201731249 |
| Publisher version: | http://dx.doi.org/10.1051/0004-6361/201731249 |
| Language: | English |
| Additional information: | This version is the version of record. For information on re-use, please refer to the publisher’s terms and conditions. |
| Keywords: | Science & Technology, Physical Sciences, Astronomy & Astrophysics, stars: formation, ISM: jets and outflows, ISM: molecules, ISM: individual objects: L1157-B1, COMPLEX ORGANIC-MOLECULES, L1157 OUTFLOW, LINE SURVEY, CHEMISTRY, COMPUTATIONS, CORES, GHZ |
| UCL classification: | UCL UCL > Provost and Vice Provost Offices > UCL BEAMS UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences UCL > Provost and Vice Provost Offices > UCL BEAMS > Faculty of Maths and Physical Sciences > Dept of Physics and Astronomy |
| URI: | https://discovery-pp.ucl.ac.uk/id/eprint/10033850 |
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