DOI QR코드

DOI QR Code

SUSTAINING GALAXY EVOLUTION: THE ROLE OF STELLAR FEEDBACK

  • JAVADI, ATEFEH (School of Astronomy, Institute for Research in Fundamental Sciences (IPM)) ;
  • VAN LOON, JACCO TH. (Astrophysics Group, Lennard-Jones Laboratories, Keele University) ;
  • KHOSROSHAHI, HABIB (School of Astronomy, Institute for Research in Fundamental Sciences (IPM))
  • Received : 2014.11.30
  • Accepted : 2015.06.30
  • Published : 2015.09.30

Abstract

We have conducted a near-infrared monitoring campaign at the UK InfraRed Telescope (UKIRT), of the Local Group galaxy M33. 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. The pulsating giant stars (AGB and red supergiants) are identified and their distributions are used to derive the star formation rate as a function of age. These stars are also important dust factories; we measure their dust production rates from a combination of our data with Spitzer Space Telescope mid-IR photometry. 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 superginats lose ~40% of their mass via a dusty stellar wind. We construct a 2-D map of the mass-return rate, showing a radial decline but also local enhancements due to agglomerations of massive stars. By comparing the current star formation rate with total mass input to the ISM, we conclude that the star formation in the central regions of M33 can only be sustained if gas is accreted from further out in the disc or from circum-galactic regions.

Keywords

Acknowledgement

Supported by : Royal Astronomical Society

References

  1. Javadi A., van Loon J. Th., & Mirtorabi M. T., 2011a, The UK Infrared Telescope M33 Monitoring Project - I. Variable Red Giant Stars in the Central Square Kiloparsec, MNRAS, 411, 263 https://doi.org/10.1111/j.1365-2966.2010.17678.x
  2. Javadi A., van Loon J. Th., Mirtorabi M. T., 2011b, The UK Infrared Telescope M33 Monitoring Project - II. The Star Formation History in the Central Square Kiloparsec MNRAS, 414, 3394 https://doi.org/10.1111/j.1365-2966.2011.18638.x
  3. Javadi A., van Loon J. Th., Khosroshahi H., Mirtorabi M. T., 2013, The UK Infrared Telescope M33 Monitoring project - III. Feedback from Dusty Stellar Winds in the Central Square Kiloparsec, MNRAS, 432, 2824 https://doi.org/10.1093/mnras/stt640
  4. Javadi A., Saberi M., van Loon J. Th., Khosroshahi H., Golabatooni N., & Mirtorabi M. T., 2014, MNRAS submitted
  5. Kang X., Chang R., Yin J., Hou J., Zhang F., Zhang Y., & Han Z., 2012, The Evolution and Star-formation History of M33, MNRAS, 426, 1455 https://doi.org/10.1111/j.1365-2966.2012.21778.x
  6. van Loon J. Th., Cioni M.-R.L., Zijlstar A.A., & Loup C., 2005, An Empirical Formula for the Mass-loss Rates of Dust-enshrouded Red Supergiants and Oxygen-rich Asymptotic Giant Branch Stars, A&A, 438, 273 https://doi.org/10.1051/0004-6361:20042555