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ALMA observations require slower Core Accretion runaway growth
journal contributionposted on 2019-09-16, 11:30 authored by S Nayakshin, G Dipierro, J Szulágyi
Due to recent high-resolution ALMA observations, there is an accumulating evidence for presence of giant planets with masses from ∼0.01 MJ to a few MJ with separations up to 100 au in the annular structures observed in young protoplanetary discs. We point out that these observations set unique ‘live’ constraints on the process of gas accretion on to subJovian planets that were not previously available. Accordingly, we use a population synthesis approach in a new way: we build time-resolved models and compare the properties of the synthetic planets with the ALMA data at the same age. Applying the widely used gas accretion formulae leads to a deficit of sub-Jovian planets and an overabundance of a few Jupiter mass planets compared to observations. We find that gas accretion rate on to planets needs to be suppressed by about an order of magnitude to match the observed planet mass function. This slower gas giant growth predicts that the planet mass should correlate positively with the age of the protoplanetary disc, albeit with a large scatter. This effect is not clearly present in the ALMA data but may be confirmed in the near future with more observations.
SN acknowledges support from STFC grants ST/N000757/1 and ST/M006948/1 to the University of Leicester. GD acknowledges financial support from the European Research Council (ERC) under the European Union’s Horizon 2020 research and innovation programme (grant agreement No 681601). JS acknowledges the funding from the Swiss National Science Foundation (SNSF) Ambizione grant PZ00P2_174115.
CitationMonthly Notices of the Royal Astronomical Society, 2019, 488 (1), pp. L12-L17 (6)
Author affiliation/Organisation/COLLEGE OF SCIENCE AND ENGINEERING/Department of Physics and Astronomy
- VoR (Version of Record)