A JWST inventory of protoplanetary disk ices. The edge-on protoplanetary disk HH 48 NE, seen with the Ice Age ERS program

Vol. 680
6. Interstellar and circumstellar matter

A JWST inventory of protoplanetary disk ices. The edge-on protoplanetary disk HH 48 NE, seen with the Ice Age ERS program

Ices are the main carriers of volatiles in protoplanetary disks and play a major role in the complex chemistry that sets the organic composition of planets. To spatially resolve their emission in the edge-on protoplanetary disk HH 48 NE, Ardjan Sturm and collaborators have used the NIRSpec instrument on board the James Webb Space Telescope (JWST). Their observations, which achieve angular resolutions of 17-28 au, reveal spatially resolved absorption features of the major ice components H2O, CO2, and CO as well as multiple weaker signatures from less abundant ices, NH3, OCN-, and OCS. The observations also show that the absorption feature of the main CO2 isotopolog is saturated despite presenting emission at its bottom due to the contribution from an ice-free ambient scattered-light continuum, and that an accurate CO2 column density can be determined using only the information from the rare 13CO2 isotopolog (first detected here in a protoplanetary disk). Overall, these observations show the great potential of JWST to explore the full inventory of protoplanetary disk ices and the importance of radiative transfer analysis in constraining their physical origin.