Simple molecules and complex chemistry in a protoplanetary disk

Astronomy and Astrophysics, vol. 697, pp. A53

Abstract

Context. While the number of detected molecules, particularly complex organic molecules, in the solid state in astrophysical environments is still rather limited, laboratory experiments and astrochemical models predict many potential candidates. Detection of molecules in protoplanetary disks provides a bridge between the chemical evolution of the interstellar medium and the chemistry of planets and their atmospheres. Aims. The excellent spectral sensitivity, broad wavelength coverage, and high spatial resolution of the James Webb Space Telescope (JWST) allows us to make progress in exploring chemical compositions of various astrophysical environments, including planet-forming disks. They are a prerequisite for probing the disk content by means of sensitive absorption studies. Methods. In this paper we present the initial results of the JWST Cycle 1 GO programme 1741 on d216-0939, a highly inclined TTauri disk located in the outskirts of the Orion Nebula Cluster. We utilised the NIRSpec and MIRI integral field unit spectrographs to cover its spectrum from 1.7 to 28 μm. Results. The spectra of the d216-0939 disk show clear absorption signatures of amorphous silicates and ices. We unambiguously detected the solid-state features of H 2 O, CO 2 , 13 CO 2 , CO, OCN − , and tentatively OCS ices, species that had also been detected recently in other circumstellar disks. For the first time in disks, we provide unique detections of ices carrying NH 4 + and the complex organic molecule ammonium carbamate (NH 4 + NH 2 COO − ). Conclusions. The latter detections speak for a very efficient NH 3 chemistry in the disk. We also show the very important role of scattering in the analysis of observational spectra of highly inclined disks.

Authors 7

1. А. В. Потапов

   Max Planck Institute for Astronomy · Friedrich Schiller University Jena

   Affiliation as printed

   Analytical Mineralogy Group, Institute of Geosciences, Friedrich Schiller University Jena, Jena, Germany

   Max Planck Institute for Astronomy, Heidelberg, Germany

2. Hendrik Linz

   Max Planck Institute for Astronomy · Friedrich Schiller University Jena

   Affiliation as printed

   Analytical Mineralogy Group, Institute of Geosciences, Friedrich Schiller University Jena, Jena, Germany

   Max Planck Institute for Astronomy, Heidelberg, Germany

3. Jeroen Bouwman

   Max Planck Institute for Astronomy

   Affiliation as printed

   Max Planck Institute for Astronomy, Heidelberg, Germany

4. W. R. M. Rocha Aachen Laboratory for Astrophysics, Leiden Observatory

   Leiden University · Leiden Observatory

   Affiliation as printed

   Laboratory for Astrophysics, Leiden Observatory, Leiden University, Leiden, The Netherlands

5. Sebastian Wolf

   Christian-Albrechts-Universität zu Kiel

   Affiliation as printed

   Institute of Theoretical Physics and Astrophysics, Kiel University, Leibnizstr. 15, 24118, Kiel, Germany

6. Thomas K. Henning

   Max Planck Institute for Astronomy

   Affiliation as printed

   Max Planck Institute for Astronomy, Heidelberg, Germany

7. Hiroshi Terada

   National Astronomical Observatory of Japan

   Affiliation as printed

   National Astronomical Observatory of Japan, Tokyo, Japan