Modelling the Spatial Distribution and Origin of CO Gas in Debris Disks

Abstract

The detection of gas in debris disks raises the question of whether this gas is a remnant from the primordial protoplanetary phase, or released by the collision of secondary bodies. In this paper we analyze ALMA observations at 1-1.5" resolution of three debris disks where the ${}^{12}$CO(2-1) rotational line was detected: HD131835, HD138813, and HD156623. We apply the iterative Lucy-Richardson deconvolution technique to the problem of circumstellar disks to derive disk geometries and surface brightness distributions of the gas. The derived disk parameters are used as input for thermochemical models to test both primordial and cometary scenarios for the origin of the gas. We favor a secondary origin for the gas in these disks and find that the CO gas masses ($\sim 3\times 10^{-3}$ M${}_{\oplus }$) require production rates ($\sim 5\times 10^{-7}$ M${}_{\oplus }$~yr${}^{-1}$) similar to those estimated for the bona-fide gas rich debris disk $\beta$ Pic.

accepted for publication in ApJ

References in corpus (20)

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Cited by in corpus (10)

• Thermophysical evolution of planetesimals in the Primordial Disk
• Population synthesis of exocometary gas around A stars
• ALMA Observations of the HD~110058 debris disk
• Primordial or Secondary? Testing models of debris disk gas with ALMA
• Physical conditions of gas components in debris disks of 49 Ceti and HD 21997
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) IV: CO gas imaging and overview
• Formation of the warped debris disc around $\beta$ Pictoris
• Abundance analysis of stars hosting gas-rich debris disks
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS). X. Interpreting the peculiar dust rings around HD 131835
• Molecules with ALMA at Planet-forming Scales (MAPS). XV. Tracing protoplanetary disk structure within 20 au