The Subaru/Hyper Suprime-Cam Medium-Band Survey: New Window for Cosmology and Galaxy Studies

This program will support the manufacturing of a new set of optical filters to be installed in the Hyper Suprime-Cam of the Subaru telescope located in Hawaii. The set of filters built with the support of this program will allow the detailed study of the most distant galaxies in the Universe. The proposed work uses an instrumental design that is innovative and allows the filter set to be easily installed on the telescope. The proposed work uses an innovative design to divide one filter slot into four colors, allowing 16 filters to be installed in just 4 filter slots. This project will train the next generation of scientists in astronomical instrumentation. The PI of this program will partner with the public outreach offices of the Subaru Telescope and the University of Arizona to create science projects accessible to everyone in the states of Arizona and Hawaii. The additional filters to be built under this program, the four reddest bands covering 800-1000 nm, will significantly enhance the science outputs of the Subaru HSC MB survey, especially by extending the redshift baseline. This survey plans to use 56 nights in the Subaru telescope. This new filter set will provide crucial complementary data for the study of high-redshift galaxies. Additional Medium Band filters will improve the sampling of the Spectral Energy Distribution (SED) of distant galaxies, increasing accuracy in the measurements of their physical properties and their photometric redshifts. The new set of filters will contribute high-quality data to the study of galaxy-galaxy lensing, galaxy clustering, large-scale structure, and dark matter. This program will benefit the entire US astronomical community as US researchers will have access to Subaru observing time through time exchange programs such as the one run by the NSF/NOIRLab. Moreover, the NSF/DOE/Rubin Observatory will receive 50 Subaru nights as an in-kind contribution from Japan. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.