Search for Optically Dark Infrared Galaxies without Counterparts of Subaru Hyper Suprime-Cam in the AKARI North Ecliptic Pole Wide Survey Field
Toba, Yoshiki, Goto, Tomotsugu, Oi, Nagisa, Wang, Ting-Wen, Kim, Seong Jin, Ho, Simon C-C, Burgarella, Denis, Hashimoto, Tetsuya, Hsieh, Bau-Ching, Huang, Ting-Chi, Hwang, Ho Seong, Ikeda, Hiroyuki, Kim, Helen K, Kim, Seongjae, Lee, Dongseob, Malkan, Matthew A, Matsuhara, Hideo, Miyaji, Takamitsu, Momose, Rieko, Ohyama, Youichi, Oyabu, Shinki, Pearson, Chris, Santos, Daryl Joe D, Shim, Hyunjin, Takagi, Toshinobu, Ueda, Yoshihiro, Utsumi, Yousuke, Wada, Takehiko
Abstract
We present the physical properties of AKARI sources without optical\ncounterparts in optical images from the Hyper Suprime-Cam (HSC) on the Subaru\ntelescope. Using the AKARI infrared (IR) source catalog and HSC optical\ncatalog, we select 583 objects that do not have HSC counterparts in the AKARI\nNorth Ecliptic Pole (NEP) wide survey field ($\\sim 5$ deg$^{2}$). Because the\nHSC limiting magnitude is deep ($g_{\\rm AB}$ $\\sim 28.6$), these are good\ncandidates for extremely red star-forming galaxies (SFGs) and/or active\ngalactic nuclei (AGNs), possibly at high redshifts. We compile multi-wavelength\ndata out to 500 $\\mu$m and use it for Spectral Energy Distribution (SED)\nfitting with CIGALE to investigate the physical properties of AKARI galaxies\nwithout optical counterparts. We also compare their physical quantities with\nAKARI mid-IR selected galaxies with HSC counterparts. The estimated redshifts\nof AKARI objects without HSC counterparts range up to $z\\sim 4$, significantly\nhigher than that of AKARI objects with HSC counterparts. We find that: (i) 3.6\n$-$ 4.5 $\\mu$m color, (ii) AGN luminosity, (iii) stellar mass, (iv) star\nformation rate, and (v) $V$-band dust attenuation in the interstellar medium of\nAKARI objects without HSC counterparts are systematically larger than those of\nAKARI objects with counterparts. These results suggest that our sample includes\nluminous, heavily dust-obscured SFGs/AGNs at $z\\sim 1-4$ that are missed by\nprevious optical surveys, providing very interesting targets for the coming\nJames Webb Space Telescope era.