Detectability of embedded protoplanets from hydrodynamical simulations

Monthly Notices of the Royal Astronomical Society, vol. 492, pp. 3440–3458

Abstract

ABSTRACT We predict magnitudes for young planets embedded in transition discs, still affected by extinction due to material in the disc. We focus on Jupiter-sized planets at a late stage of their formation, when the planet has carved a deep gap in the gas and dust distributions and the disc starts to being transparent to the planet flux in the infrared (IR). Column densities are estimated by means of three-dimensional hydrodynamical models, performed for several planet masses. Expected magnitudes are obtained by using typical extinction properties of the disc material and evolutionary models of giant planets. For the simulated cases located at 5.2 au in a disc with a local unperturbed surface density of 127 $\mathrm{g} \, \mathrm{cm}^{-2}$, a 1MJ planet is highly extinct in the J, H, and Kbands, with predicted absolute magnitudes ≥ 50 mag. In the L and Mbands, extinction decreases, with planet magnitudes between 25 and 35 mag. In the Nband, due to the silicate feature on the dust opacities, the expected magnitude increases to ∼40 mag. For a 2MJ planet, the magnitudes in the J, H, and Kbands are above 22 mag, while for the L, M, and Nbands, the planet magnitudes are between 15 and 20 mag. For the 5MJ planet, extinction does not play a role in any IR band, due to its ability to open deep gaps. Contrast curves are derived for the transition discs in CQ Tau, PDS 70, HL Tau, TW Hya, and HD 163296. Planet mass upper limits are estimated for the known gaps in the last two systems.

Authors 5

1. Enrique Sanchis corresponding

   European Southern Observatory · Ludwig-Maximilians-Universität München

   Affiliation as printed

   European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, Germany

   Universitäts-Sternwarte, Ludwig-Maximilians-Universität München, Scheinerstrasse 1, D-81679 München, Germany

2. Giovanni Picogna

   Ludwig-Maximilians-Universität München

   Affiliation as printed

   Universitäts-Sternwarte, Ludwig-Maximilians-Universität München, Scheinerstrasse 1, D-81679 München, Germany

3. Barbara Ercolano

   Excellence Cluster Origins · Ludwig-Maximilians-Universität München

   Affiliation as printed

   Excellence Cluster Origins, Boltzmannstrasse 2, D-85748 Garching bei München, Germany

   Universitäts-Sternwarte, Ludwig-Maximilians-Universität München, Scheinerstrasse 1, D-81679 München, Germany

4. L. Testi

   European Southern Observatory · Arcetri Astrophysical Observatory · Excellence Cluster Origins

   Affiliation as printed

   European Southern Observatory, Karl-Schwarzschild-Strasse 2, D-85748 Garching bei München, Germany

   Excellence Cluster Origins, Boltzmannstrasse 2, D-85748 Garching bei München, Germany

   INAF/Osservatorio Astrofisico di Arcetri, Largo E. Fermi 5, I-50125 Firenze, Italy

5. Giovanni P. Rosotti Aachen Leiden Observatory

   Leiden University · University of Cambridge · Leiden Observatory

   Affiliation as printed

   Institute of Astronomy, University of Cambridge, Madingley Road, Cambridge CB3 0HA, UK

   Leiden Observatory, Leiden University, PO Box 9531, NL-2300 RA Leiden, the Netherlands