Predictions for the secondary CO, C and O gas content of debris discs from the destruction of volatile-rich planetesimals

Abstract

This paper uses observations of dusty debris discs, including a growing number of gas detections in these systems, to test our understanding of the origin and evolution of this gaseous component. It is assumed that all debris discs with icy planetesimals create second generation CO, C and O gas at some level, and the aim of this paper is to predict that level and assess its observability. We present a new semi-analytical equivalent of the numerical model of Kral et al. (2016) allowing application to large numbers of systems.That model assumes CO is produced from volatile-rich solid bodies at a rate that can be predicted from the debris disc's fractional luminosity. CO photodissociates rapidly into C and O that then evolve by viscous spreading. This model provides a good qualitative explanation of all current observations, with a few exceptional systems that likely have primordial gas. The radial location of the debris and stellar luminosity explain some non-detections, e.g. close-in debris (like HD 172555) is too warm to retain CO, while high stellar luminosities (like $\eta$ Tel) result in short CO lifetimes. We list the most promising targets for gas detections, predicting $>15$ CO detections and $>30$ CI detections with ALMA, and tens of CII and OI detections with future far-IR missions. We find that CO, CI, CII and OI gas should be modelled in non-LTE for most stars, and that CO, CI and OI lines will be optically thick for the most gas-rich systems. Finally, we find that radiation pressure, which can blow out CI around early-type stars, can be suppressed by self-shielding.

Paper in press, MNRAS, 34 pages

References in corpus (25)

• New Grids of ATLAS9 Model Atmospheres
• The 2013 Release of Cloudy
• Molecular Gas Clumps from the Destruction of Icy Bodies in the $\beta$ Pictoris Debris Disk
• Radiative recombination data for modelling dynamic finite-density plasmas
• Long-Term Collisional Evolution of Debris Disks
• Collisional processes and size distribution in spatially extended debris discs
• The Carbon-Rich Gas in the Beta Pictoris Circumstellar Disk
• Abundant Circumstellar Silica Dust and SiO Gas Created by a Giant Hypervelocity Collision in the ~12 Myr HD172555 System
• Debris from giant impacts between planetary embryos at large orbital radii
• Do Two Temperature Debris Disks Have Multiple Belts?
• Debris Disks in the Scorpius-Centaurus OB Association Resolved by ALMA
• Exocometary gas structure, origin and physical properties around $\beta$ Pictoris through ALMA CO multi-transition observations
• Survival of icy grains in debris discs. The role of photosputtering
• ALMA observations of the $\eta$ Corvi debris disc: inward scattering of CO-rich exocomets by a chain of 3-30 M${}_{\oplus }$ planets?
• Five steps in the evolution from protoplanetary to debris disk
• A Resolved Molecular Gas Disk around the Nearby A Star 49 Ceti
• CO mass upper limits in the Fomalhaut ring - the importance of NLTE excitation in debris discs and future prospects with ALMA
• Gas and dust in the Beta Pictoris Moving Group as seen by the Herschel Space Observatory
• Gas and dust around A-type stars at tens of Myr:signatures of cometary breakup
• A CO survey in planet-forming disks: characterizing the gas content in the epoch of planet formation
• Photodissociation of small carbonaceous molecules of astrophysical interest
• Volatile-Rich Circumstellar Gas in the Unusual 49 Ceti Debris Disk
• Signatures of massive collisions in debris discs
• First Detection of Hydrogen in the β Pictoris Gas Disk
• Constraints on the gas content of the Fomalhaut debris belt. Can gas-dust interactions explain the belt's morphology?

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• Resolving the outer ring of HD 38206 using ALMA and constraining limits on planets in the system
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• Debris Disks: Probing Planet Formation
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• A catalog of collected debris disks: properties, classifications and correlations between disks and stars/planets
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• Multi-wavelength, spatially resolved modelling of HD 48682's debris disc
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• High CO/H2 ratios supports an exocometary origin for a CO-rich debris disk
• HD 44892: The youngest (or oldest?) gas-harbouring debris disc around an intermediate mass star
• Water vapor as a probe of the origin of gas in debris disks
• The formation of planetary systems with SPICA
• The Inbound Gas and Dust Evolution of Interstellar Comet 3I/ATLAS from Optical Spectroscopy and Multi-band Photometry
• The search for gas in debris discs: ALMA detection of CO gas in HD 36546