학술논문
Water in the terrestrial planet-forming zone of the PDS 70 disk
Document Type
Working Paper
Author
Perotti, G.; Christiaens, V.; Henning, Th.; Tabone, B.; Waters, L. B. F. M.; Kamp, I.; Olofsson, G.; Grant, S. L.; Gasman, D.; Bouwman, J.; Samland, M.; Franceschi, R.; van Dishoeck, E. F.; Schwarz, K.; Güdel, M.; Lagage, P. -O.; Ray, T. P.; Vandenbussche, B.; Abergel, A.; Absil, O.; Arabhavi, A. M.; Argyriou, I.; Barrado, D.; Boccaletti, A.; Garatti, A. Caratti o; Geers, V.; Glauser, A. M.; Justannont, K.; Lahuis, F.; Mueller, M.; Nehmé, C.; Pantin, E.; Scheithauer, S.; Waelkens, C.; Guadarrama, R.; Jang, H.; Kanwar, J.; Morales-Calderón, M.; Pawellek, N.; Rodgers-Lee, D.; Schreiber, J.; Colina, L.; Greve, T. R.; Östlin, G.; Wright, G.
Source
Subject
Language
Abstract
Terrestrial and sub-Neptune planets are expected to form in the inner ($<10~$AU) regions of protoplanetary disks. Water plays a key role in their formation, although it is yet unclear whether water molecules are formed in-situ or transported from the outer disk. So far Spitzer Space Telescope observations have only provided water luminosity upper limits for dust-depleted inner disks, similar to PDS 70, the first system with direct confirmation of protoplanet presence. Here we report JWST observations of PDS 70, a benchmark target to search for water in a disk hosting a large ($\sim54~$AU) planet-carved gap separating an inner and outer disk. Our findings show water in the inner disk of PDS 70. This implies that potential terrestrial planets forming therein have access to a water reservoir. The column densities of water vapour suggest in-situ formation via a reaction sequence involving O, H$_2$, and/or OH, and survival through water self-shielding. This is also supported by the presence of CO$_2$ emission, another molecule sensitive to UV photodissociation. Dust shielding, and replenishment of both gas and small dust from the outer disk, may also play a role in sustaining the water reservoir. Our observations also reveal a strong variability of the mid-infrared spectral energy distribution, pointing to a change of inner disk geometry.
Comment: To appear in Nature on 24 July 2023. 21 pages, 10 figures; includes extended data. Part of the JWST MINDS Guaranteed Time Observations program's science enabling products. Spectra downloadable on Zenodo at https://zenodo.org/record/7991022
Comment: To appear in Nature on 24 July 2023. 21 pages, 10 figures; includes extended data. Part of the JWST MINDS Guaranteed Time Observations program's science enabling products. Spectra downloadable on Zenodo at https://zenodo.org/record/7991022