Volume 634, February 2020
|Number of page(s)||12|
|Section||Interstellar and circumstellar matter|
|Published online||13 February 2020|
Mass constraints for 15 protoplanetary discs from HD 1–0
Institute of Astronomy, University of Cambridge,
2 Tartu Observatory, Observatooriumi 1, Tõravere 61602, Tartu, Estonia
3 Leiden Observatory, Leiden University, Niels Bohrweg 2, 2333 CA Leiden, The Netherlands
4 INAF – Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, 50125 Firenze, Italy
5 Max-Planck-institute für extraterrestrische Physic, Giessenbachstraße, 85748 Garching bei München, Germany
6 Anton Pannekoek Institute for Astronomy, University of Amsterdam, Science Park 904, 1090 GE Amsterdam, The Netherlands
7 European Southern Observatory, Karl-Schwarzschild-Str. 2, 85748 Garching bei München, Germany
8 Department of Astronomy, University of Michigan, 1085 S. University Ave, Ann Arbor, MI 48109, USA
Accepted: 22 December 2019
Context. Hydrogen deuteride (HD) rotational line emission can provide reliable protoplanetary disc gas mass measurements, but this molecule is difficult to observe and detections have been limited to three T Tauri discs. No new data have been available since the Herschel Space Observatory mission ended in 2013.
Aims. We set out to obtain new disc gas mass constraints by analysing upper limits on HD 1–0 emission in Herschel/PACS archival data from the DIGIT key programme.
Methods. With a focus on the Herbig Ae/Be discs, whose stars are more luminous than T Tauris, we determined upper limits for HD in data previously analysed for its line detections. We studied the significance of these limits with a grid of models run with the DALI physical-chemical code, customised to include deuterium chemistry.
Results. Nearly all the discs are constrained to Mgas ≤ 0.1 M⊙, ruling out global gravitational instability. A strong constraint is obtained for the HD 163296 disc mass, Mgas ≤ 0.067 M⊙, implying Δg/d ≤ 100. This HD-based mass limit is towards the low end of CO-based mass estimates for the disc, highlighting the large uncertainty in using only CO and suggesting that gas-phase CO depletion in HD 163296 is at most a factor of a few. The Mgas limits for HD 163296 and HD 100546, both bright discs with massive candidate protoplanetary systems, suggest disc-to-planet mass conversion efficiencies of Mp/(Mgas + Mp) ≈ 10–40% for present-day values. Near-future observations with SOFIA/HIRMES will be able to detect HD in the brightest Herbig Ae/Be discs within 150 pc with ≈ 10 h integration time.
Key words: planets and satellites: formation / protoplanetary discs / circumstellar matter / planets and satellites: gaseous planets
© ESO 2020
Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.
Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.
Initial download of the metrics may take a while.