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Colloquium
Dust-obscured AGN viewed with multi-wavelength data

Abstract

I will present the physical and statistical properties of dust-obscured AGN as observed through multi-wavelength data. Specifically, my primary focus will be on infrared (IR)-bright dust-obscured galaxies (DOGs) with i - [22] > 7.0 in AB magnitude and a flux density at 22 um > 1.0 mJy. These IR-bright DOGs constitute a subset of optically-faint luminous IR galaxies, typically observed at high redshifts (z~1-3) such as ULIRGs and HyLIRGs. Hydrodynamic simulations suggest that black holes within IR-bright DOGs exhibit their most significant accretion rates during major merger events. This implies that these DOGs likely play a crucial role in understanding the co-evolution of galaxies and supermassive black holes. However, due to their spatial rarity, extensive wide-area surveys employing both optical and IR wavelengths are required for their detection. To date, we have systematically searched for obscured AGN (including DOGs) and examined their statistical and physical characteristics using multi-wavelength data, e.g., the SDSS, Subaru/HSC, WISE, AKARI, ALMA, NuSTAR, and eROSITA. In this talk, I will particularly focus on the following aspects: (i) luminosity function and luminosity density, (ii) clustering properties, (iii) ionized and molecular gas properties, and (iv) AGN and its host properties.