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Seeds of Life in Space – SOLIS

Life on Earth is based on carbon chemistry, likely because of the C atoms ability to form long chains and polymers and its relatively large cosmic abundance. The same chemistry holds everywhere in the Universe and it starts in the interstellar clouds, from where the progenitors of Suns and Solar-like planetary systems are born. As the Nobel Laureate C. de Duve (2005) wrote: “The building blocks of life form naturally in our Galaxy and, most likely, also elsewhere in the cosmos. The chemical seeds of life are universal.”  As a matter of fact, out of more than 270 species detected in the ISM, about 80% contain C atoms, and all species with more than five atoms are C-bearing ones. The latter are known as interstellar Complex Organic Molecules (iCOMs) and may represent the foundational organic chemistry underlying terrestrial life.

SOLIS is a NOEMA Large Program which has the overall goal of understanding the organic chemistry during the first steps of the formation of a Solar-like planetary system.

To this end, the immediate SOLIS objective is to provide a homogeneous data set of observations of five crucial iCOMs in seven targets representative of Solar-like systems in their first evolutionary stages.  The observations are designed to map several lines from each of the targeted iCOMs and, hence, determine their abundance as well as the physical conditions of the region where the lines are emitted, with a precision on 10000—100 au scales. Thanks to the NOEMA capabilities, several more iCOMs are detected that complement the primary species targeted, allowing for a more comprehensive chemical study of the observed regions.

SOLIS has observed the following seven sources: L1544, representative of prestellar cores; L1521, a VeLLO (Very Low-Luminosity) source at the very early stages of protostellar evolution; NGC 1333-IRAS4A, a low-luminosity Class 0 binary system; CepE-mm, an intermediate-luminosity Class 0 source; NGC 1333-SVS13A, a low-luminosity Class I binary system; OMC-2 FIR4, a protocluster analogue of the one where the Solar System was born; L1157-B1, a molecular shock close to a Class 0 source.

SOLIS has targeted the following five iCOMs: methanol (CH3OH), considered the mother of many other iCOMs; dimethyl ether (CH3OCH3; DME), methyl formate (HCOOCH3: MF) and formamide (NH2HCO), three commonly observed iCOMs that have been predicted to be formed both in the gas-phase and on the grain surfaces; methoxy (CH3O), a crucial precursor of several iCOMs.

In addition, the SOLIS observations have provided information on acetaldehyde (CH3CHO), methyl cyanide (CH3CN), the two smallest cyanopolyynes (HC3N and HC5N), among other iCOMs, as well as simpler molecules such as S-bearing ones or rarer isotopologues of hydrogen, nitrogen and silicon.

The official SOLIS repository is at IRAM, and it includes various types of data, such as uv-tables, continuum emission maps, and continuum-subtracted data cubes.

Please do not hesitate to contact Cecilia Ceccarelli ( and Paola Caselli ( for further questions or to inform them about the use of the data for further scientific analysis or publications. For a complete list of publications please visit the SOLIS publication web page.

The following acknowledgment would be appreciated: “This work made use of data from the NOEMA Large Program SOLIS (Seeds Of Life In Space), Ceccarelli & Caselli et al. 2017, ApJ 850, 176.”