Tracing planet-induced structures in circumstellar disks using molecular lines

Abstract

Circumstellar disks are considered to be the birthplace of planets. Specific structures like spiral arms, gaps, and cavities are characteristic indicators of planet-disk interaction. Investigating these structures can provide insights into the growth of protoplanets and the physical properties of the disk. We investigate the feasibility of using molecular lines to trace planet-induced structures in circumstellar disks. Based on 3D hydrodynamic simulations of planet-disk interactions, we perform self-consistent temperature calculations and produce N-LTE molecular line velocity-channel maps and spectra of these disks using our new N-LTE line radiative transfer code Mol3D. Subsequently, we simulate ALMA observations using the CASA simulator. We consider two nearly face-on inclinations, 5 disk masses, 7 disk radii, and 2 different typical pre-main-sequence host stars (T Tauri, Herbig Ae). We calculate up to 141 individual velocity-channel maps for five molecules/isotopoloques in a total of 32 rotational transitions to investigate the frequency dependence of the structures indicated above. We find that the majority of protoplanetary disks in our parameter space could be detected in the molecular lines considered. However, unlike the continuum case, gap detection is not straightforward in lines. For example, gaps are not seen in symmetric rings but are masked by the pattern caused by the global (Keplerian) velocity field. We identify specific regions in the velocity-channel maps that are characteristic of planet-induced structures. Simulations of high angular resolution molecular line observations demonstrate the potential of ALMA to provide complementary information about the planet-disk interaction as compared to continuum observations. In particular, the detection of planet-induced gaps is possible under certain conditions.(abridged)

19 pages, 19 figures, accepted for publication in A&A

References in corpus (14)

• PLUTO: a Numerical Code for Computational Astrophysics
• Gaps, Rings, and Non-Axisymmetric Structures in Protoplanetary Disks - From Simulations to ALMA Observations
• Dust flow in gas disks in the presence of embedded planets
• Mid-Infrared Spectroscopy of Disks around Classical T Tauri Stars
• Cold CO in circumstellar disks: On the effects of photodesorption and vertical mixing
• Gas-phase CO in protoplanetary disks: a challenge for turbulent mixing
• 3D MHD Simulations of Planet Migration in Turbulent Stratified Disks
• The T Tauri star RY Tau as a case study of the inner regions of circumstellar dust disks
• Planet gaps in the dust layer of 3D protoplanetary disks. II. Observability with ALMA
• Molecular line radiative transfer in protoplanetary disks: Monte Carlo simulations versus approximate methods
• Tracing large-scale structures in circumstellar disks with ALMA
• Chemical and thermal structure of protoplanetary disks as observed with ALMA
• Molecular Emission Line Formation in Prestellar Cores
• Planet-induced disk structures: A comparison between (sub)mm and infrared radiation

Cited by in corpus (5)

• HD 169142 in the eyes of ZIMPOL/SPHERE
• Magnetic fields in circumstellar disks: The potential of Zeeman observations
• The scattering order problem in Monte Carlo radiative transfer
• The potential of combining MATISSE and ALMA observations: Constraining the structure of the innermost region in protoplanetary discs
• Impact of Size-dependent Grain Temperature on Gas-Grain Chemistry in Protoplanetary Disks: the case of low mass star disks