Princeton University Thunch Talk

This talk will present the first results of the MIRI-MRS spectra of a number of protostars, T Tauri and brown dwarf disks resulting from the JOYS and MINDS GTO programs. Rich ice spectra are seen in the cold outer envelopes of protostars hinting at the presence of complex molecules in ices. In young and mature disks, many lines from gaseous CO, H2O, CO2, C2H2 and HCN are found, but also surprising new molecules are detected. Together they point to a rich chemistry that is linked to the physical structure of the inner regions of these disks and thereby provides a unique diagnostic of it.

As background information: the 55 hr JWST Observations of Young protoStars (JOYS) GTO program (PI: van Dishoeck) uses MIRI to investigate the physical and chemical properties of two dozen protostars and their immediate environment. JOYS studies the physical characteristics of embedded disks, accretion signatures onto the protostars, feedback from the young protostars on their environment through primordial jets and outflows, as well as the chemical gas and ice constituents of the protostellar envelopes to feed the disks.

The goal of the 120 hr MIRI Mid INfrared Disk Survey (MINDS) GTO program (Th. Henning, I. Kamp co-PIs) is to use JWST to (1) investigate the chemical inventory of the terrestrial planet forming zone, (2) to follow the gas evolution into the disk dispersal stage, and to (3) study the structure of protoplanetary and debris disks in the thermal mid-IR. The program builds a bridge between the chemical inventory of planet-forming disks and the properties of exoplanets. In total, about 50 targets (Herbig Ae stars, T Tauri stars, brown dwarfs and young debris disks) will be observed.