The UK Infrared Telescope M33 monitoring project – III. Feedback from dusty stellar winds in the central square kiloparsec

Javadi, Atefeh; van Loon, Jacco Th.; Khosroshahi, Habib; Mirtorabi, Mohammad Taghi

Abstract

We have conducted a near-infrared monitoring campaign at the UK Infrared Telescope, of the Local Group spiral galaxy M33 (Triangulum). The main aim was to identify stars in the very final stage of their evolution, and for which the luminosity is more directly related to the birth mass than the more numerous less evolved giant stars that continue to increase in luminosity. In this third paper of the series, we measure the dust production and rates of mass-loss by the pulsating asymptotic giant branch (AGB) stars and red supergiants. To this aim, we combined our time-averaged near-IR photometry with the multi-epoch mid-IR photometry obtained with the Spitzer Space Telescope. The mass-loss rates are seen to increase with increasing strength of pulsation and with increasing bolometric luminosity. Low-mass stars lose most of their mass through stellar winds, but even super-AGB stars and red supergiants lose ∼40 per cent of their mass via a dusty stellar wind. More than three-quarters of the dust return is oxygenous. We construct a 2D map of the mass-return rate, showing a radial decline but also local enhancements due to agglomerations of massive stars. We estimate a total mass-loss rate of 0.004–0.005 M⊙ yr−1 kpc−2, increasing to ∼0.006 M⊙ yr−1 kpc−2 when accounting for eruptive mass-loss (e.g., supernovae); comparing this to the current star formation rate of ∼0.03 M⊙ yr−1 kpc−2 we conclude that star formation in the central region of M33 can only be sustained if gas is accreted from further out in the disc or from circumgalactic regions.

Citation

Javadi, A., van Loon, J. T., Khosroshahi, H., & Mirtorabi, M. T. (2013). The UK Infrared Telescope M33 monitoring project – III. Feedback from dusty stellar winds in the central square kiloparsec. Monthly Notices of the Royal Astronomical Society, 432(4), 2824-2836. https://doi.org/10.1093/mnras/stt640

• Journal Article Type: Article
• Acceptance Date: Apr 11, 2013
• Online Publication Date: May 21, 2013
• Publication Date: May 21, 2013
• Deposit Date: Jun 16, 2023
• Journal: Monthly Notices of the Royal Astronomical Society
• Print ISSN: 0035-8711
• Electronic ISSN: 1365-2966
• Publisher: Oxford University Press
• Peer Reviewed: Peer Reviewed
• Volume: 432
• Issue: 4
• Pages: 2824-2836
• DOI: https://doi.org/10.1093/mnras/stt640
• Keywords: Space and Planetary Science; Astronomy and Astrophysics; stars: AGB and post-AGB, stars: carbon, stars: mass-loss, supergiants, galaxies: individual: M33, galaxies: structure