TY - JOUR
T1 - Dusty spirals triggered by shadows in transition discs
AU - Cuello, N.
AU - Montesinos, M.
AU - Stammler, S. M.
AU - Louvet, F.
AU - Cuadra, J.
N1 - Funding Information:
Acknowledgements. We thank the two anonymous referees who have reviewed this manuscript for the very constructive comments which allowed us to improve the quality of this work. N.C. acknowledges financial support provided by FONDECYT grant 3170680. N.C., M.M., and J.C. acknowledge financial support from Millenium Nucleus grant RC130007 (Chilean Ministry of Economy). M.M. acknowledges support from the Millennium Science Initiative (Chilean Ministry of Economy) and the CHINA-CONICYT fund, 4th call. S.M.S. gratefully acknowledges support through the PUC-HD Graduate Student Exchange Fellowship, which is part of the academic exchange programme between the Institute of Astrophysics of the Pontificia Universidad Católica (IA-PUC) and the Center for Astrophysics at the University of Heidelberg (ZAH), financed by the German Academic Exchange Service (DAAD). This work was partly carried out while J.C. was on sabbatical leave at MPE. J.C. and N.C. acknowledge the kind hospitality of MPE, and funding from the Max Planck Society through a “Partner Group” grant. J.C. acknowledges support from CONICYT-Chile through FONDECYT (1141175) and Basal (PFB0609) grants, and from the ICM (Iniciativa Científica Milenio) via the Núcleo Milenio de Formación Planetaria grant. The Geryon/Geryon2 cluster housed at the Centro de Astro-Ingenieria UC was used for the calculations performed in this paper. The BASAL PFB-06 CATA, Anillo ACT-86, FONDEQUIP AIC-57, and QUIMAL 130008 provided funding for several improvements to the Geryon/Geryon2 cluster.
Publisher Copyright:
© ESO 2019.
PY - 2019/2/1
Y1 - 2019/2/1
N2 - Context. Despite the recent discovery of spiral-shaped features in protoplanetary discs in the near-infrared and millimetre wavelengths, there is still an active discussion to understand how they formed. In fact, the spiral waves observed in discs around young stars can be due to different physical mechanisms: planet/companion torques, gravitational perturbations, or illumination effects. Aims. We study the spirals formed in the gaseous phase by two diametrically opposed shadows cast at fixed disc locations. The shadows are created by an inclined non-precessing disc inside the cavity, which is assumed to be optically thick. In particular, we analyse the effect of these spirals on the dynamics of the dust particles and discuss their detectability in transition discs. Methods. We performed gaseous hydrodynamical simulations with shadows, then we computed the dust evolution on top of the gaseous distribution, and finally we produced synthetic ALMA observations of the dust emission based on radiative transfer calculations. Results. Our main finding is that millimetre- to centimetre-sized dust particles are efficiently trapped inside the shadow-triggered spirals. We also observe that particles of various sizes starting at different stellocentric distances are well mixed inside these pressure maxima. This dynamical effect would favour grain growth and affect the resulting composition of planetesimals in the disc. In addition, our radiative transfer calculations show spiral patterns in the disc at 1.6 μm and 1.3 mm. Due to their faint thermal emission (compared to the bright inner regions of the disc) the spirals cannot be detected with ALMA. However, our synthetic observations prove that shadows are observable as dips in the thermal emission.
AB - Context. Despite the recent discovery of spiral-shaped features in protoplanetary discs in the near-infrared and millimetre wavelengths, there is still an active discussion to understand how they formed. In fact, the spiral waves observed in discs around young stars can be due to different physical mechanisms: planet/companion torques, gravitational perturbations, or illumination effects. Aims. We study the spirals formed in the gaseous phase by two diametrically opposed shadows cast at fixed disc locations. The shadows are created by an inclined non-precessing disc inside the cavity, which is assumed to be optically thick. In particular, we analyse the effect of these spirals on the dynamics of the dust particles and discuss their detectability in transition discs. Methods. We performed gaseous hydrodynamical simulations with shadows, then we computed the dust evolution on top of the gaseous distribution, and finally we produced synthetic ALMA observations of the dust emission based on radiative transfer calculations. Results. Our main finding is that millimetre- to centimetre-sized dust particles are efficiently trapped inside the shadow-triggered spirals. We also observe that particles of various sizes starting at different stellocentric distances are well mixed inside these pressure maxima. This dynamical effect would favour grain growth and affect the resulting composition of planetesimals in the disc. In addition, our radiative transfer calculations show spiral patterns in the disc at 1.6 μm and 1.3 mm. Due to their faint thermal emission (compared to the bright inner regions of the disc) the spirals cannot be detected with ALMA. However, our synthetic observations prove that shadows are observable as dips in the thermal emission.
KW - Hydrodynamics
KW - Methods: numerical
KW - Planets and satellites: formation
KW - Protoplanetary disks
KW - Radiative transfer
UR - http://www.scopus.com/inward/record.url?scp=85060892277&partnerID=8YFLogxK
U2 - 10.1051/0004-6361/201731732
DO - 10.1051/0004-6361/201731732
M3 - Article
AN - SCOPUS:85060892277
SN - 0004-6361
VL - 622
JO - Astronomy and Astrophysics
JF - Astronomy and Astrophysics
M1 - A43
ER -