Planet-induced disk structures: A comparison between (sub)mm and infrared radiation

Abstract

Context. Young giant planets, which are embedded in a circumstellar disk, will significantly perturb the disk density distribution. This effect can potentially be used as an indirect tracer for planets. Aims. We investigate the feasibility of observing planet-induced gaps in circumstellar disks in scattered light. Methods. We perform 3D hydrodynamical disk simulations combined with subsequent radiative transfer calculations in scattered light for different star, disk, and planet configurations. The results are compared to those of a corresponding study for the (sub)mm thermal re-emission. Results. The feasibility of detecting planet-induced gaps in scattered light is mainly influenced by the optical depth of the disk and therefore by the disk size and mass. Planet-induced gaps are in general only detectable if the photosphere of the disks is sufficiently disturbed. Within the limitations given by the parameter space here considered, we find that gap detection is possible in the case of disks with masses below ∼10 −4···−3 M . Compared to the disk mass that marks the lower Atacama Large (Sub)Millimeter Array (ALMA) detection limit for the thermal radiation re-emitted by the disk, it is possible to detect the same gap both in re-emission and scattered light only in a narrow range of disk masses around ∼10 −4 M , corresponding to 16% of cases considered in our study.

Interferometric study on the temporal variability of the brightness distributions of protoplanetary disks

“…Furthermore, such observations enable us to study another intriguing type of temporal variability: variations in the brightness distribution due to the orbital motion of asymmetric features in the disk. These asymmetries, such as spiral density arms and local hot spots, may result from planet-disk interactions, allowing us to derive planetary and disk parameters (Brunngräber & Wolf 2018;Ruge et al 2014Ruge et al , 2013Wolf & D'Angelo 2005).…”

Hiding in the Shadows. Ii. Collisional Dust as Exoplanet Markers

“…The morphology of a gap can be used to infer properties of the disk (Paardekooper & Mellema 2004;Fouchet et al 2007;Crida et al 2006), with large gaps being indicative of either massive companions or multiple companions (Espaillat et al 2014;Dodson-Robinson & Salyk 2011;Dong et al 2015). In early studies, due to numerical constraints, it was assumed that the dust and gas in a disk were well mixed, and models of observations still use this method (D'Alessio et al 1998;Ruge et al 2014). However, due to the imperfect coupling of larger dust grains to the gas, it is argued that the observed structures vary with wavelength (Rice et al 2006;Pinilla et al 2012;Zhu et al 2012;Gonzalez et al 2012).…”

Tracing planet-induced structures in circumstellar disks using molecular lines

“…Wolf & D'Angelo (2005) and Ruge et al (2013) showed the possibility of tracing gaps in continuum re-emission light for various disk configurations and ALMA configurations. In addition, Ruge et al (2014) investigated the feasibility of tracing gaps in continuum re-emission maps and scattered light images simultaneously. In contrast to this, only a few studies exist investigating the feasibility of tracing planet-induced structures through molecular line observations.…”