The Nearby Evolved Stars Survey III: First data release of JCMT CO-line observations

Abstract

Low- to intermediate-mass ($\sim$0.8$-$8 M${}_{\odot }$) evolved stars contribute significantly to the chemical enrichment of the interstellar medium in the local Universe, making accurate mass-return estimates in their final stages crucial. The Nearby Evolved Stars Survey (NESS) is a large multi-telescope project targeting a volume-limited sample of $\sim$850 stars within 3 kpc in order to derive the dust and gas return rates in the Solar Neighbourhood, and to constrain the physics underlying these processes. We present an initial analysis of the CO-line observations, including detection statistics, carbon isotopic ratios, initial mass-loss rates, and gas-to-dust ratios. We describe a new data reduction pipeline to analyse the available NESS CO data from the JCMT, measuring line parameters and calculating empirical gas mass-loss rates. We present the first release of the available data on 485 sources, one of the largest homogeneous samples of CO data to date. Comparison with a large literature sample finds that high mass-loss rate and especially carbon-rich sources are over-represented in literature, while NESS is probing significantly more sources at low mass-loss rates, detecting 59 sources in CO for the first time and providing useful upper limits. CO line detection rates are 81% for the CO (2--1) line and 75% for CO (3--2). The majority (82%) of detected lines conform to the expected soft parabola shape, while eleven sources show a double wind. Calculated mass-loss rates show power-law relations with both the dust-production rates and expansion velocities up to $\sim 5\times 10^{-6}$~\msunyr. Median gas-to-dust ratios of 250 and 680 are found for oxygen-rich and carbon-rich sources, respectively. Our analysis of CO observations in this first data release highlights the importance of our volume-limited approach in characterizing the local AGB population as a whole.

arXiv comment18 pages, 12 figures, accepted for publication in Astronomy & Astrophysics, data to be made available at https://evolvedstars.space

References in corpus (42)

• Array Programming with NumPy
• Astropy: A Community Python Package for Astronomy
• emcee: The MCMC Hammer
• The Astropy Project: Sustaining and Growing a Community-oriented Open-source Project and the Latest Major Release (v5.0) of the Core Package
• Binary companions of evolved stars in APOGEE DR14: Search method and catalog of ~5,000 companions
• The SIMBAD astronomical database
• The Dawes Review 2: Nucleosynthesis and stellar yields of low and intermediate-mass single stars
• The Evolution of Isotope Ratios in the Milky Way Galaxy
• Stellar yields from metal-rich asymptotic giant branch models
• Fundamental parameters and infrared excesses of Hipparcos stars
• Probing the mass-loss history of AGB and red supergiant stars from CO rotational line profiles - II. CO line survey of evolved stars: derivation of mass-loss rate formulae
• HARP/ACSIS: A submillimetre spectral imaging system on the James Clerk Maxwell Telescope
• Models of circumstellar molecular radio line emission: Mass loss rates for a sample of bright carbon stars
• Mass loss rates of a sample of irregular and semiregular M-type AGB-variables
• `Thermal' SiO radio line emission towards M-type AGB stars: a probe of circumstellar dust formation and dynamics
• On the reliability of mass-loss-rate estimates for AGB stars
• The Dust Budget of the SMC: Are AGB Stars the Primary Dust Source at Low Metallicity?
• The Mass-Loss Return From Evolved Stars to The Large Magellanic Cloud VI: Luminosities and Mass-Loss Rates on Population Scales
• Fundamental parameters and infrared excesses of Tycho-Gaia stars
• Circumstellar molecular line emission from S-type AGB stars: Mass-loss rates and SiO abundances
• pyspeckit: A spectroscopic analysis and plotting package
• New observations and models of circumstellar CO line emission of AGB stars in the Herschel SUCCESS programme
• The growth of carbon chains in IRC+10216 mapped with ALMA
• The mass-loss return from evolved stars to the Large Magellanic Cloud V. The GRAMS carbon-star model grid
• Mass loss and rotational CO emission from Asymptotic Giant Branch stars
• The evolved-star dust budget of the Small Magellanic Cloud: the critical role of a few key players
• The Mass-Loss Return from Evolved Stars to the Large Magellanic Cloud IV: Construction and Validation of a Grid of Models for Oxygen-Rich AGB Stars, Red Supergiants, and Extreme AGB Stars
• The evolution of DARWIN: current status of wind models for AGB stars
• An extensive grid of DARWIN models for M-type AGB stars I. Mass-loss rates and other properties of dust-driven winds
• The Abundance of SiC2 in Carbon Star Envelopes: Evidence that SiC2 is a gas-phase precursor of SiC dust
• Circumstellar shells and mass loss rates: Clues to the evolution of S stars
• Automated reduction of submillimetre single-dish heterodyne data from the James Clerk Maxwell Telescope using ORAC-DR
• The variable mass loss of the AGB star WX Psc as traced by the CO J=1-0 through 7-6 lines and the dust emission
• Carbon star wind models at solar and sub-solar metallicities: a comparative study. I. Mass loss and the properties of dust-driven winds
• Carbon abundances and 12C/13C from globular cluster giants
• The ALMA detection of CO rotational line emission in AGB stars in the Large Magellanic Cloud
• The abundance of S- and Si-bearing molecules in O-rich circumstellar envelopes of AGB stars
• ATOMIUM: Molecular inventory of 17 oxygen-rich evolved stars observed with ALMA
• The mass-loss rates of red supergiants at low metallicity: Detection of rotational CO emission from two red supergiants in the Large Magellanic Cloud
• Structure and dynamics of the inner nebula around the symbiotic stellar system R Aqr
• Morpho-kinematics of the wind of AGB star L${}_2$ Pup
• CO and HCN isotopologue ratios in the outflows of AGB stars

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