천문우주과학과

Quasars, the brightest population of the active galactic nuclei (AGNs), radiate a huge amount of multi-wavelength fluxes by accreting surrounded materials into their central supermassive black holes (SMBHs). This bright quasar light allows astronomers to explore the distant universe, millions of years after the Big Bang. In this talk, I will present how our group found more than 20 faint quasars at redshifts of 5-6, based on the Infrared Medium-deep Survey (IMS), a near-infrared imaging survey with United Kingdom Infrared Telescope (UKIRT). With these quasars, we studied (1) the quasar’s role in the early ionization of the intergalactic medium by deriving quasar luminosity functions (QLFs), (2) how the QLFs evolve across the cosmic time, and (3) the growth (or co-evolution) of their central SMBHs and host galaxies using the multi-wavelength data. Finally, I will briefly introduce my current work on quasars at various redshifts.

관련 논문 :

Kim, Y., Im, M., Jeon, Y., et al. 2020, ApJ, 904, 111 (https://ui.adsabs.harvard.edu/abs/2020ApJ...904..111K/abstract)

Kim, Y., Im, M., Jeon, Y., et al. 2022, AJ, 164, 114 (https://ui.adsabs.harvard.edu/abs/2022AJ....164..114K/abstract)