Observations of primordial (redshift greater than five) galaxies have shown that they contain large amounts of dust. The stars in these galaxies are young (ages less than one billion years), so the dust cannot be attributed to asymptotic giant branch stars or Type Ia supernovae, both of which take longer to develop/evolve to dust producing stages. However, dust produced by massive stars (red supergiants and Type II supernovae) may explain the high dust content of these galaxies. Yet very little is known about dust formation in these objects. This three-year project will attempt to characterize the dust produced by massive stars in the local universe and, in particular, address the key question as to whether the Type II supernovae and red supergiant stars alone could produce the amount of dust seen in primordial galaxies.
Here, moderate resolution spectra of large samples of red supergiants in the Large and Small Magellanic Clouds with near- and mid-infrared photometry will be modeled to reveal their underlying spectral energy distribution and wavelength dependent reddening. A significant sample of late-time observations (spectra and photometry) of type II supernovae will also be compiled and the amount and nature of the dust production by these objects will be determined. The composition, size distribution, extinction, and re-emission properties of this dust will be studied using Monte Carlo radiative transfer codes, maximum entropy, and multilayer sphere methods. These results are expected to advance our knowledge of the role supernovae and red supergiants play, via dust production and distribution, in the formation and evolution of the first galaxies formed after the big bang.
As these results will have a broad impact in the wider astronomical community, the data and models will be made publicly available on a website. This program will be useful in planning observations for future instruments such as The Atacama Large Millimeter Array and the James Webb Space Telescope. Among the high priority science goals of these telescopes is the detailed study of high-redshift galaxies and their dust content. Both a postdoctoral researcher and a graduate student will be trained through this project. Discussion of this research on dust will also be included in Dr. Clayton''s team-taught astronomy/science fiction course at the LSU Learning Community.
