Dust mass-loss rates from AGB stars in the Fornax and Sagittarius dwarf Spheroidal galaxies

Abstract

To study the effect of metallicity on the mass-loss rate of asymptotic giant branch (AGB) stars, we have conducted mid-infrared photometric measurements of such stars in the Sagittarius (Sgr dSph) and Fornax dwarf spheroidal galaxies with the 10-$\mu$m camera VISIR at the VLT. We derive mass-loss rates for 29 AGB stars in Sgr dSph and 2 in Fornax. The dust mass-loss rates are estimated from the $K-[9]$ and $K-[11]$ colours. Radiative transfer models are used to check the consistency of the method. Published IRAS and Spitzer data confirm that the same tight correlation between $K-[12]$ colour and dust mass-loss rates is observed for AGB stars from galaxies with different metallicities, i.e. the Galaxy, the LMC and the SMC. The derived dust mass-loss rates are in the range 5$\times 10^{-10}$ to 3$\times 10^{-8}$ M${}_{\odot }$yr${}^{-1}$ for the observed AGB stars in Sgr dSph and around 5$\times 10^{-9}$ M${}_{\odot }$yr${}^{-1}$ for those in Fornax; while values obtained with the two different methods are of the same order of magnitude. The mass-loss rates for these stars are higher than the nuclear burning rates, so they will terminate their AGB phase by the depletion of their stellar mantles before their core can grow significantly. Some observed stars have lower mass-loss rates than the minimum value predicted by theoretical models.

arXiv comment12 pages, 9 figures, accepted for publication in MNRAS

References in corpus (22)

• Color Transformations for the 2MASS Second Incremental Data Release
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: I. Morphology of the Sagittarius Core and Tidal Arms
• A 2MASS All-Sky View of the Sagittarius Dwarf Galaxy: IV. Modeling the Sagittarius Tidal Tails
• A-type Supergiant Abundances in the SMC: Probes of Evolution
• A step toward the calibration of the RGB Tip as a Standard Candle
• Near-Infrared Photometry of Carbon Stars
• User Manual for DUSTY
• A Spitzer mid-infrared spectral survey of mass-losing carbon stars in the Large Magellanic Cloud
• Dusty winds: I. Self-similar solutions
• The Sgr dSph hosts a metal-rich population
• The Chemical Enrichment History of the Fornax Dwarf Spheroidal Galaxy from the Infrared Calcium Triplet
• MSX, 2MASS, and the LMC: A Combined Near and Mid Infrared View
• Dust-enshrouded giants in clusters in the Magellanic Clouds
• Spitzer spectroscopy of carbon stars in the Small Magellanic Cloud
• Low-mass supernovae in the early Galactic halo: source of the double r/s-process enriched halo stars?
• Three-micron spectra of AGB stars and supergiants in nearby galaxies
• The age of the main population of the Sagittarius dwarf spheroidal galaxy. Solving the "M giant conundrum"
• The Planetary Nebula population of the Sagittarius Dwarf Spheroidal Galaxy
• Cool carbon stars in the halo: a new survey based on 2MASS
• A Spitzer/IRAC Census of the Asymptotic Giant Branch Populations in Local Group Dwarfs. I. WLM
• The distance to the Fornax dwarf galaxy using red clump stars, and the discrepancy between red clump and tip of the red giant branch distances
• On determining the mass-loss rates of red giants and red supergiants based on infrared data

Cited by in corpus (20)

• The ACS Nearby Galaxy Survey Treasury IX. Constraining asymptotic giant branch evolution with old metal-poor galaxies
• The global gas and dust budget of the Large Magellanic Cloud: AGB stars and supernovae, and the impact on the ISM evolution
• ALMA data suggest the presence of a spiral structure in the inner wind of CW Leo
• Dust in Historical Galactic Type Ia Supernova Remnants with Herschel
• AGB Stars in the Fornax Dwarf Spheroidal Galaxy
• Silicon carbide absorption features: dust formation in the outflows of extreme carbon stars
• On the need of the Light Elements Primary Process (LEPP)
• The trigger of the AGB superwind: the importance of carbon
• Spitzer Space Telescope spectral observations of AGB stars in the Fornax dwarf spheroidal galaxy
• Optical constants of silicon carbide for astrophysical applications. II. Extending optical functions from IR to UV using single-crystal absorption spectra
• The low wind expansion velocity of metal-poor carbon stars in the Halo and the Sagittarius stream
• Metal-rich carbon stars in the Sagittarius Dwarf Spheroidal galaxy
• VISTA variables in the Sagittarius dwarf spheroidal galaxy: pulsation- vs. dust-driven winds on the giant branches
• Near-infrared spectroscopy of AGB star candidates in Fornax, Sculptor and NGC 6822
• Disk evaporation in a planetary nebula
• Searching for Anomalies in the ZTF Catalog of Periodic Variable Stars
• A near-infrared study of AGB and red giant stars in the Leo I dSph galaxy
• The dust and gas content of carbon stars toward the Galactic Halo
• Modeling Dust Production, Growth, and Destruction in Reionization-Era Galaxies with the CROC Simulations: Methods and Parameter Exploration
• An Infrared Photometric and Spectroscopic Study of Post-AGB Stars