The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) IV: CO gas imaging and overview

Abstract

CO gas is detected in a significant number of debris discs, but its origin and evolution remains unclear. Key constraints are its mass and spectro-spatial distribution, which are coupled through optical depth and have only been analysed at low to moderate resolution so far. The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) is the first ALMA large program to target debris discs at high spectro-spatial resolution. We used ${}^{12}$CO and ${}^{13}$CO J=3-2 line data of 18 ARKS debris belts, 5 of which were already known to host gas, to analyse the spectro-spatial distribution of CO, constrain the gas masses, and to search for gas in the remaining systems. We developed a line-imaging pipeline and produced line cubes for each disc, with a spatial resolution down to $\sim$70 mas and spectral resolution of 26 m s${}^{-1}$. Using spectro-spatial shifting and stacking, we produced high signal-to-noise maps, and radial and spectral profiles that reveal the distribution and kinematics of gas in 5 gas-bearing discs. For these discs, we constrained the inner radius of the ${}^{12}$CO, and found the radial brightness profile of CO peaked interior to the dust ring, but that CO was more radially extended than the dust. We present the first radially resolved ${}^{12}$CO/${}^{13}$CO isotopologue flux ratios in gas-bearing debris discs, which are constant with radius for the majority of systems, indicating ${}^{12}$CO and ${}^{13}$CO are both optically thick or thin throughout the discs. We report CO line fluxes/upper limits for all systems and optical depth dependant masses for the 5 gas-bearing systems. Finally, we analysed the ${}^{12}$CO J=3-2 line luminosities for the ARKS debris discs and discs from the literature. We confirm that gas is mostly detected in young systems. However, the high scatter seen in young/high fractional luminosity systems indicates no trend within the systems with detected gas.

21 pages, 8 figures, 5 tables, published in A&A

References in corpus (41)

• Gaia Data Release 3: Summary of the content and survey properties
• CASA, the Common Astronomy Software Applications for Radio Astronomy
• Multi-Scale CLEAN deconvolution of radio synthesis images
• Transience of hot dust around sun-like stars
• Pulkovo Compilation of Radial Velocities for 35495 Hipparcos Stars in a Common System
• Molecular Gas Clumps from the Destruction of Icy Bodies in the $\beta$ Pictoris Debris Disk
• Detection of exocometary CO within the 440 Myr-old Fomalhaut belt: a similar CO+CO${}_2$ ice abundance in exocomets and Solar System comets
• 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
• Molecular gas in debris disks around young A-type stars
• Survival of icy grains in debris discs. The role of photosputtering
• Kuiper Belt-Like Hot and Cold Populations of Planetesimal Inclinations in the $\beta$ Pictoris Belt Revealed by ALMA
• CO mass upper limits in the Fomalhaut ring - the importance of NLTE excitation in debris discs and future prospects with ALMA
• Stacking Spectra in Protoplanetary Disks: Detecting Intensity Profiles from Hidden Molecular Lines in HD 163296
• Planet populations inferred from debris discs: insights from 178 debris systems in the ISPY, LEECH and LIStEN planet-hunting surveys
• The Mass of Stirring Bodies in the AU Mic Debris Disk Inferred from Resolved Vertical Structure
• ALMA observations of the narrow HR 4796A debris ring
• A gap in HD 92945's broad planetesimal disc revealed by ALMA
• Population synthesis of exocometary gas around A stars
• On the Ubiquity and Stellar Luminosity Dependence of Exocometary CO Gas: Detection around M Dwarf TWA 7
• A detailed characterization of HR 8799's debris disk with ALMA in Band 7
• Search for associations containing young stars (SACY) VIII. An updated census of spectroscopic binary systems showing hints of non-universal multiplicity among these associations
• Volatile-Rich Circumstellar Gas in the Unusual 49 Ceti Debris Disk
• Survey of planetesimal belts with ALMA: gas detected around the Sun-like star HD 129590
• Subaru/SCExAO First-Light Direct Imaging of a Young Debris Disk around HD 36546
• ALMA Survey of Lupus Class III Stars: Early Planetesimal Belt Formation and Rapid Disk Dispersal
• New debris disks in nearby young moving groups
• Photoevaporation of Grain-Depleted Protoplanetary Disks around Intermediate-Mass Stars: Investigating Possibility of Gas-Rich Debris Disks as Protoplanetary Remnants
• Lack of other molecules in CO-rich debris discs: is it primordial or secondary gas?
• The Age of the Carina Young Association and Potential Membership of HD 95086
• Primordial or Secondary? Testing models of debris disk gas with ALMA
• Carbon monoxide gas produced by a giant impact in the inner region of a young system
• Resolving Structure in the Debris Disk around HD 206893 with ALMA
• Vertical evolution of exocometary gas: I. How vertical diffusion shortens the CO lifetime
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) I: Motivation, sample, data reduction, and results overview
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) II. The radial structure of debris discs
• Modelling the Spatial Distribution and Origin of CO Gas in Debris Disks
• Rapid CO gas dispersal from NO Lup's class III circumstellar disc
• Morphology of the gas-rich debris disk around HD 121617 with SPHERE observations in polarized light
• Resolving the outer ring of HD 38206 using ALMA and constraining limits on planets in the system
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) III: The vertical structure of debris disks

Cited by in corpus (7)

• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS): VI. Asymmetries and offsets
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) V: Comparison between scattered light and thermal emission
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) VII: Optically thick gas with broad CO gaussian local line profiles in the HD 121617 disc
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) VIII: A dust arc and non-Keplerian gas kinematics in HD 121617
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS). X. Interpreting the peculiar dust rings around HD 131835
• High CO/H2 ratios supports an exocometary origin for a CO-rich debris disk
• The ALMA survey to Resolve exoKuiper belt Substructures (ARKS) XI: Gas-dust interactions and radial offsets between micron and millimetre-sized grains