# # Program information file # PROGRAM_ID 2023A060 PROGRAM_TITLE A SpeX View of Nuclear Transients PROGRAM_INV1 Jason Hinkle PROGRAM_INV2 Benjamin Shappee PROGRAM_INV3 Anna Payne PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT extra-galactic PROGRAM_ABSTRACT_BEG Nuclear transients, such as tidal disruption events [TDEs] and active galactic nuclei [AGN] flares promise to give detailed insight into supermassive black hole [SMBH] properties and galaxy nuclear environments. Currently however, the physics behind the observed emission is poorly understood. One notable gap in our knowledge of these nuclear transients is near-infrared [NIR] spectroscopy. The NIR provides a window into emission lines that are difficult to observe in the optical, giving additional leverage on ionization conditions and the central SMBH mass. We propose to obtain some of the first NIR spectra of nuclear transients using SpeX on the IRTF. SpeX in PRISM mode for faint sources and SXD mode for bright sources will allow us to establish a sample of moderate S/N spectra of nuclear transients in the NIR. PRISM mode is also well-matched to the very broad emission lines commonly seen in TDEs. These observations will primarily target emission lines from H, He, and highly excited coronal lines typically seen in strong AGNs. This will add much-needed context to the growing sample of exotic and ambiguous nuclear transients fueled by the recent growth of optical all-sky surveys. As the sample of TDEs with robust multi-wavelength observations grows, we can begin to fulfill the promise of using TDEs as a tool to study SMBHs at cosmological distances. We request 5 half-nights spaced throughout the semester and alternating first/second half to maximize our ability to conduct long-term NIR spectral monitoring for bright nuclear transients, including TDEs, AGN flares, and dramatic examples of changing-look AGNs. PROGRAM_ABSTRACT_END