Dr. Takamiya will use the University of Hawaii's 2.2-meter telescope, and the new 0.9-meter telescope dedicated to UH-Hilo, to take images of 30 nearby galaxies in the light of hydrogen gas that has been heated by nearby young stars. Young stars are generally surrounded by dusty gas, out of which they have formed. The dust absorbs some of the light from the hot gas, blocking blue light more strongly than red. Dr Takamiya will compare images of her galaxies in both the red line of H-alpha and the green line of H-beta, to estimate how strong the blocking effect is. A further check will come from maps in the mid-infrared made from space observations, and maps at radio wavelengths, since these are almost unaffected by dust. The results obtained in nearby galaxies will be extrapolated to distant disk galaxies, where in general only lines such as H-alpha at optical wavelengths can be measured easily for large samples. This extrapolation will yield better estimates of the rate at which galaxies have formed their stars throughout cosmic history.
This project will provide research opportunities to undergraduate students at Dr. Takamiya's institution. Six undergraduate students will be hired to participate in writing observing proposals to gain access to telescopes on Mauna Kea, to carry out the observations, reduce and analyze them, and to present the results in professional meetings. The University of Hawaii at Hilo is located in the most ethnically diverse county in the USA, and members of under-represented groups will be encouraged to participate in this research. Dr Takamiya will also continue her outreach work to local elementary schools.
