Water in the terrestrial planet-forming zone of the PDS 70 disk
Journal article, 2023
Terrestrial and sub-Neptune planets are expected to form in the inner (less than 10 au) regions of protoplanetary disks 1. Water plays a key role in their formation 2–4, although it is yet unclear whether water molecules are formed in situ or transported from the outer disk 5,6. So far Spitzer Space Telescope observations have only provided water luminosity upper limits for dust-depleted inner disks 7, similar to PDS 70, the first system with direct confirmation of protoplanet presence 8,9. Here we report JWST observations of PDS 70, a benchmark target to search for water in a disk hosting a large (approximately 54 au) planet-carved gap separating an inner and outer disk 10,11. 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, H2 and/or OH, and survival through water self-shielding 5. This is also supported by the presence of CO2 emission, another molecule sensitive to ultraviolet 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 12. Our observations also reveal a strong variability of the mid-infrared spectral energy distribution, pointing to a change of inner disk geometry.
Author
G. Perotti
Max Planck Society
Valentin Christiaens
University of Liège
T. Henning
Max Planck Society
Benoît Tabone
Institut d'Astrophysique Spatiale
Lbfm Waters
Radboud University
Netherlands Institute for Space Research (SRON)
I. Kamp
University of Groningen
G. Olofsson
Stockholm University
Sierra L. Grant
Max Planck Society
Danny Gasman
KU Leuven
J. Bouwman
Max Planck Society
Matthias Samland
Max Planck Society
R. Franceschi
Max Planck Society
E. F. van Dishoeck
Leiden University
Max Planck Society
Kamber Schwarz
Max Planck Society
M. Gudel
Max Planck Society
University of Vienna
Swiss Federal Institute of Technology in Zürich (ETH)
P. O. Lagage
University Paris-Saclay
Tom Ray
Dublin Institute for Advanced Studies
B. Vandenbussche
KU Leuven
Alain Abergel
Institut d'Astrophysique Spatiale
O. Absil
University of Liège
Aditya M. Arabhavi
University of Groningen
Ioannis Argyriou
KU Leuven
D. Barrado
Centro de Astrobiologia (CAB)
Anthony Boccaletti
Paris Observatory
A. Caratti o. Garatti
Dublin Institute for Advanced Studies
Osservatorio Astronomico di Capodimonte
V. C. Geers
Royal Observatory
A. M. Glauser
Swiss Federal Institute of Technology in Zürich (ETH)
Kay Justtanont
Chalmers, Space, Earth and Environment, Astronomy and Plasmaphysics
F. Lahuis
Netherlands Institute for Space Research (SRON)
M. Mueller
University of Groningen
Cyrine Nehmé
University Paris-Saclay
E. Pantin
University Paris-Saclay
S. Scheithauer
Max Planck Society
C. Waelkens
KU Leuven
Rodrigo Guadarrama
University of Vienna
Hyerin Jang
Radboud University
Jayatee Kanwar
Institut fur Weltraumforschung
University of Groningen
Technische Universität Graz
M. Morales-Calderon
Centro de Astrobiologia (CAB)
Nicole Pawellek
University of Vienna
Donna Rodgers-Lee
Dublin Institute for Advanced Studies
J. Schreiber
Max Planck Society
L. Colina
Centro de Astrobiologia (CAB)
T. R. Greve
Technical University of Denmark (DTU)
G. Östlin
The Oskar Klein Centre
G. Wright
Royal Observatory
Nature
0028-0836 (ISSN) 1476-4687 (eISSN)
Vol. 620 7974 516-520Subject Categories
Astronomy, Astrophysics and Cosmology
DOI
10.1038/s41586-023-06317-9
PubMed
37488359