Collaborative Research: The True Chemical Abundances of Spiral Galaxies

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Exactly how galaxies form and develop is a mystery that has long eluded astronomers. So, it is crucial for scientists to unravel clues of galaxy formation and development. This project focuses on one very important clue to this mystery in spiral galaxies: how the chemical makeup (abundance) of the interstellar medium (ISM) of nearby spiral galaxies is spatially distributed. The investigators have carefully chosen a specific set of galaxies for this study from the Spitzer Infrared Nearby Galaxies Survey (SINGS) because SINGS galaxies have excellent multiwavelength observations already available to aid the investigators in interpreting the data that they will obtain in this project. Using the Multi-Object Double Spectrograph (MODS) on the Large Binocular Telescope (LBT), the investigators will observe high quality emission line spectra of approximately 1000 ionized gas (H II) regions of 13 SINGS galaxies, increasing the number of previously observed H II regions by more than a factor of 10. Securing these new measurements will allow the investigators to address several scientific topics: (1) the dispersion of the ISM chemical abundances as a function of radius, (2) chemical abundance radial gradients in spiral galaxies, (3) the yields of elements from stellar nucleosynthesis with potential constraints on the stellar initial mass function, (4) the chemical development of galaxies at much greater distances (high redshift), and (5) the chemical enrichment history of the Universe.For each of the three years, this project will help fund the education of one graduate student from an underrepresented group (a female), will provide a summer research position for an undergraduate, and will fund a postdoctoral scientist. Both principal investigators are also heavily involved in public outreach activities to benefit their communities.