Advanced Astronomical Instrumentation and Observational Studies of Supernovae and Remnants

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The research programs proposed in this application are twofold. First, I plan to develop advanced astronomical instruments and novel devices, especially a microshtter array (MSA)-based infrared multi-object spectrograph (IRMOS) and polarization gratings, as well as the imminent commissioning of two other infrared spectrographs. These new instruments and device, once successfully developed, will be an important advancement in how we conduct astronomical observations. Along with the instrument development, I plan to conduct research centered on observations of supernovae (SNe) and supernova remnants (SNRs). For the former, I will focus on early SNe and rare types using a new powerful facility that provides the unprecedented 24-hour continuous sky coverage. For the latter, my efforts will lie on understanding nucleosyntheses and element production in core-collapse SNe via near-infrared (NIR) spectroscopy of ejecta in SNRs. I hope that ultimately the results of my programs bring us significantly improved observational capabilities for astronomy and better understanding of how SNe explode and how elements, including those indispensable to life (e.g., phosphorous), are produced. The participation of students and postdoctoral fellows is an essential and inevitable component for the success of the proposed research.* "Advanced Instrumentation": First, the MSA-based IRMOS, which I plan to develop with recent funding from CFI, will bring us for the first time a fully reconfigurable multi-object spectroscopic capability compatible with wide field adaptive optics systems of large telescopes. I am collaborating with the NASA team that originally developed the MSA for the NIRSpec instrument on JWST to use the device for ground-based applications. We will use a spare MSA as a reconfigurable source selector at a reimaged telescope focal plane of the planned IRMOS, which will allow us simultaneous spectroscopic observations ~100 objects. Next, recent rapid developments in the fields of nanofabrication and photonics now make it possible to fabricate gratings that can arbitrarily manipulate photon's polarization states with sub-wavelength structures. These gratings, so called polarization gratings, deliver an almost 100% diffraction efficiency over a broad spectral range (e.g., visible to NIR). My graduate student and I are designing these gratings for astronomical applications (e.g., observations of high-redshift SNe), which can potentially revolutionize the efficiency of astronomical spectroscopy. Additionally, I expect to commission in 2014 spring-summer two other NIR spectrographs that I have developed: Near Infrared Echelle Spectrograph and Wide Integral Field Infrared Spectrograph.* "Observational Research": I recently led an international team to acquire ~30% of the total observing time of the KMTNet facility in 2014-2018 for dedicated SN observations. The KMTNet is a network of three new wide-field optical telescopes of 1.6-m diameter spread over three different countries in the southern hemisphere. Thanks to the continuous 24-hour sky coverage, it is ideally and uniquely suited for studying early SNe and rare types, which can greatly improve our understanding of how SNe explode. Conjointly with the SNe research, I am deeply interested in NIR spectroscopic investigation of SN ejecta in young SNRs using the spectrographs that I have built. The NIR waveband is rich with transitions of the elements (i.e., Fe, S, Si, P, He, etc) heavily involved in the SN nucelosynthesis, and our recent studies have proven that NIR spectroscopy is extremely useful for understanding the SN necleosynthesis and explosion mechanism by providing both chemical and dynamical information. Therefore, I plan to conduct observations of both SNe and SNRs.