IRTF Data Archive Program Information

# # Program information file # PROGRAM_ID 2023B046 PROGRAM_TITLE Unveiling hidden accretion flows in nearby enshrouded stellar disruptions with IRTF PROGRAM_INV1 Kishalay De PROGRAM_INV2 Megan Masterson PROGRAM_INV3 Christos Panagiotou PROGRAM_INV4 PROGRAM_INV5 PROGRAM_SCICAT extra-galactic PROGRAM_ABSTRACT_BEG Tidal disruption events [TDEs] occur when a star gets torn apart by a supermassive black hole [SMBH], lighting up a flare over the entire electromagnetic spectrum. Not only do these events offer a powerful probe of quiescent SMBHs, they potentially contribute significantly to the growth of SMBHs over cosmic time. Although the field of TDEs has seen an exponential growth thanks to optical and X- ray sky surveys, there is growing evidence that existing searches miss a substantial population of events where the SMBH line of sight is obscured by dust. Motivated by the recent identification of the nearest TDE ever discovered as an extremely bright mid-infrared [MIR] transient, the team has carried out the first systematic search for MIR nuclear flares in nearby galaxies [< 200 Mpc] using images from the NEOWISE MIR survey processed through state-of-the-art image subtraction techniques. Pilot follow-up optical spectroscopy of the candidates confirms that these events are largely associated with quiescent SMBHs, although direct evidence of broad accretion lines remains elusive in the optical. However, a tantalizing, broad [2000 km/s] He 10830 line was detected in a pilot single NIR spectrum of one transient, suggesting that scattered radiation of high ionization species from the central accretion disk may still be dominant as suggested by the bright MIR flux. We request 18 hours of time with the well- matched capabilities of IRTF/SpeX to confirm these signatures in 12 sources, that would conclusively confirm this spectacular population of overlooked SMBH transients. PROGRAM_ABSTRACT_END