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# Program information file
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PROGRAM_ID           2024B087
PROGRAM_TITLE        Mid-infrared spectroscopy of rapidly growing active intermediate-mass black holes
PROGRAM_INV1         Igor Chilingarian
PROGRAM_INV2         Franz Bauer
PROGRAM_INV3         Kirill Grishin
PROGRAM_INV4         Evgenii Rubtsov
PROGRAM_INV5         Victoria Toptun
PROGRAM_SCICAT       extra-galactic
PROGRAM_ABSTRACT_BEG
Confirmation of a population of intermediate black holes [IMBHs; MBH=1,000...100,000 MSun] will solve one of the long-standing problems in modern astrophysics, the origin of supermassive black holes [SMBHs]. IMBH host galaxies hold important clues to our understanding of galaxy formation and evolution processes: they might have evolved from ancient times in the early Universe without major merger events or intense gas accretion onto their nuclei and, therefore, represent the relics of primordial galaxy formation. Using publicly available X-ray data, we identify 7 unique IMBHs accreting close to the Eddington limit. Does intense BH growth in the IMBH regime affect their host galaxies? Does the growth rate stay persistent for extended periods of time? Is it the main IMBH growth channel? We propose mid-infrared spectroscopic observations of the 4 brightest active Eddington-limited IMBHs using SpeX in the 1.7-4.2um wavelength range to: [i] search for signatures of AGN-driven quenching by measuring the PAH 3.3um line; [ii] detect and measure broad Br-beta, Br-gamma, Pa-alpha hydrogen lines; [iii] search for coronal high-ionization Mg and Si lines predicted by IMBH accretion models.
PROGRAM_ABSTRACT_END