Speaker
Description
In the last six years ALMA revolutionised our comprehension of planet formation. The first breakthrough was delivered by the impactful images of rings and gaps in the dust distribution of young disks, the first direct probe of planet formation at work in disks of age less than 1 Myr. In parallel, ALMA is revolutionising also our comprehension of the disk chemistry, delivering the first inventory of molecules in disks. This is crucial to answer another key question about planet formation: what chemical composition do planets inherit from their natal environment? To answer this question is one of the goal of the SKA WG “Cradle of Life”.
To characterise the molecular content of planet-forming disks, we recently started the ALMA-DOT chemical survey of young disks in the nearby star-forming region of Taurus (140 pc). ALMA-DOT allowed us to reveal the radial and vertical distribution of several molecules at 15-50 au scales (CO, CN, CS, H2CO, H2CS, SO, SO2) and to detect methanol (CH3OH), the simplest complex organic molecule (COM) and a key brick for the formation of pre-biotic molecules. The ALMA-DOT observations also highlighted the limits of ALMA for the study of the disk chemistry: (1) ALMA is blind to molecular emission in the inner 50 au of young disks, because this is suppressed by optically thick dust emission; (2) COMs are hard to detect in disks.
To overcome these limits and detect COMs on a <50 au scale (i.e. the Solar-System scale) we crucially need to observe at cm wavelengths, where the continuum is optically thin, and a unique combination of very high sensitivity and angular resolution. This can be obtained only with deep SKA observations in band 6. A pilot project to map the H2CO snowline in disks with JVLA is ongoing to test the project feasibility and set the sensitivity requirements for SKA observations. These observations will be key to characterise the molecular content of the inner 50 au of planet-forming disks, and to infer the location of molecular snowlines. These in turn are key to understand chemical processes in disks, planet formation, and chemical inheritance of the planets atmospheres.
| Reasearch area | Cradle of Life |
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