Abstract

New planetary systems are made from dust and gas in the rotating disks around young stars. High-resolution observations of these planet-forming disks with the Atacama Large Millimeter Array (ALMA) can be used to learn about the planet-formation process. In particular, ALMA can trace the composition of the gas available to be accreted by planets. In this talk, I will show recent molecular line observations towards two well-studied warm planet-forming disks: HD100546 and IRS48 and compare these to other disks including those in the ALMA large program MAPS . The molecular emissions in HD100546 and IRS48 are strongly linked to disks dust structures. Our results include first detections of the molecules NO, SO2 and CH3OCH3 in protoplanetary disks. The array of detected molecules can be used to learn about the physical and chemical conditions in the disk experienced by forming planets. We determine the elemental C/O ratio in the disk using the simple molecules (SO, CS etc), and this provides a direct connection to the observed exoplanet population. On the other hand, the more complex molecules (CH3OH, CH3OCH3 , etc.) shed light on the importance of inheritance from earlier stages of the star formation process. The detection of these complex and potentially prebiotic molecules in planet-forming disks provides links to how life originated in our solar system.