NSF Award
2408103
While our atmosphere is transparent to visible and radio wavelengths, it is difficult to observe the near-infrared (NIR) from the ground, due to the extreme brightness and variability of the night sky at these wavelengths. The atmospheric emission in the NIR arises almost entirely from a forest of extremely bright, very narrow emission lines from OH molecules that vary on timescales of minutes. This team has recently demonstrated a technique to filter out these emission lines using technology borrowed from photonics. This project will use this photonic OH suppression filter in combination with the RIMAS instrument on the Lowell Discovery Telescope (LDT). The research team will use this new instrument to follow up extremely luminous but transient explosions of massive stars (gamma-ray bursts or GRBs). They will train graduate and undergraduate astronomy students in instrumentation and broad scientific practices at the interface of photonics and astronomy. Some of the undergraduate students will be from neighboring minority-serving institutions as part of Maryland's GRAD-MAP initiative. <br/><br/>The Maryland OH Suppression Infrared System (MOHSIS) has the potential to change the way NIR spectroscopy is done from the ground. The unique approach of MOHSIS relies on using fiber Bragg gratings, fabricated by imposing about 100,000 tiny (relative amplitude of 0.0001) variations of the refractive index along individual optical fibers. MOHSIS will be more powerful than the team’s first-generation instrument, called PRAXIS, for several reasons: (1) MOHSIS will remove the 200 strongest OH sky lines at 1.1 - 1.7 microns, covering the critically important J band between the visible and H-band spectroscopic observations. (2) MOHSIS will have lower background noise. (3) LDT will deliver image quality at least twice as good as the host telescope of PRAXIS. Moreover, LDT is ideally suited for GRB follow-ups as it allows for a fast (about 1 min) switch of instruments and simultaneous optical and NIR observations. The low-resolution spectra of optically dark GRBs will be combined with simultaneous optical photometry to derive dust extinction and accurate redshifts based on the position of the Ly-alpha break. Space Variable Objects Monitor (SVOM), which is specifically designed to find distant GRBs out to the era of the first generation of stars, will provide high-redshift GRB candidates starting 2024-25.<br/><br/>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.
