Building blocks of life

Context

Chemical complexity in rotating protostellar (HH212) and protoplanetary (DG Tau) disks as seen by ALMA (Codella 2018; Podio 2018)

Both high- and low-mass star forming regions, and more specifically, all the components of a Sun-like star formation recipe (pre-stellar cores, hot-corinos, circumstellar disks/winds, and fast jets) show emission due to interstellar Complex Organic Molecules (iCOMs; C-bearing species with at least 6 atoms), such as formamide, NH2CHO or glycoladehyde, HCOCH2OH).

Our group has started a systematic study of the chemical composition of protostars via Large Programs with the single-dish telescopes Herschel (CHESS; http://ipag.osug.fr), IRAM-30m (ASAI; www.oan.es/asai) and the IRAM-NOEMA interferometer (SOLIS; http://solis.osug.fr/).

We are carrying on also a large number of projects (including the large program FAUST, http://stars.riken.jp/faust/fausthome.html) based on the ALMA array. All these programs provided us with a rich bag of information down to Solar System scales.

The GENESIS-SKA approach is: to fully exploit the capabilities of the telescopes working in the mm- and sub-mm wavelengths to prepare pilot projects in the cm-domain and consequently plan science goals for SKA.

Goals

The ingredients for the recipe to make a “habitable” planet like our own Earth are: a relatively small rocky planet, at the right distance from the host star, with a not too thick atmosphere rich in volatiles and capable of developing interstellar complex organic molecules (iCOMs) chemistry. Searches for exoplanets have shown a large degree of diversity in the planetary systems, and as yet is unclear how common a System like our own is. Understanding the formation of planetary systems and the chemical processing of the volatiles that will form their atmospheres is key to understand the origins of the Solar System and how common the “habitable” planet outcome may be. More specifically key questions still to be addressed are: how chemically complex are the volatiles delivered on the pristine planetary atmospheres? What molecules are passed from the large-scale envelope to the disk in which planets, comets, and asteroids form?

To understand how much of this molecular complexity develops during the formation of stars and is available in the disks for delivery on the pristine planet surfaces (Codella+ 2015). This requires spatial scales < 50 au.

In the GENESIS-SKA context, we obtained the large program ALMA FAUST (co-PI: C. Codella; http://stars.riken.jp/faust/fausthome.html), the first and so far unique ALMA large program on astrochemistry (iCOMs and light C-chains: CnX, n<3; HC2n+1N, n<3) of protostellar and protoplanetary regions (15 Class 0/I sources, three frequency set-ups; at 220-260 GHz).

Synergies

An interdisciplinary approach with theoretical, modeling groups and the chemistry community is essential to understand the chemical process that lead to iCOMs in gas-phase and hence to properly set up the observational programs with SKA.

Observations are compared with theoretical quantum chemistry calculation, carried out in collaboration with the Scuola Normale Superiore in Pisa and the Bologna and Perugia Universities.