Subaru/HSC deep optical imaging of infrared sources in the AKARI North Ecliptic Pole-Wide field

Journal Article · Tue Oct 20 00:00:00 EDT 2020 · Monthly Notices of the Royal Astronomical Society

DOI:https://doi.org/10.1093/mnras/staa3080· OSTI ID:1767158

Oi, Nagisa  ^[1]; Goto, Tomotsugu ^[2]; Matsuhara, Hideo ^[3]; Utsumi, Yousuke ^[4]; Momose, Rieko ^[5]; Toba, Yoshoki  ^[6]; Malkan, Matthew ^[7]; Takagi, Toshinobu ^[8]; Huang, Ting-Chi  ^[9]; Kim, Seong Jin  ^[2]; Ohyama, Youichi ^[10]

---

1. Tokyo Univ. of Science (Japan); Kwansei Gakuin Univ., Hyogo (Japan)
2. National Tsing Hua Univ., Hsinchu (Taiwan)
3. Japan Aerospace Exploration Agency, Kanagawa (Japan); Graduate Univ. for Advanced Studies (SOKENDAI), Kanagawa (Japan)
4. SLAC National Accelerator Lab., Menlo Park, CA (United States); Stanford Univ., CA (United States). Kavli Inst. for Particle Astrophysics and Cosmology; Hiroshima Univ. (Japan)
5. National Tsing Hua Univ., Hsinchu (Taiwan); Univ. of Tokyo (Japan)
6. Academia Sinica Inst. of Astronomy and Astrophysics, Taipei (Taiwan); Kyoto Univ. (Japan); Ehime Univ. (Japan)
7. Univ. of California, Los Angeles, CA (United States)
8. Japan Space Forum, Tokyo (Japan)
9. Japan Aerospace Exploration Agency, Kanagawa (Japan)
10. Academia Sinica Inst. of Astronomy and Astrophysics, Taipei (Taiwan)

In this work, we present a five-broad-band (grizy) photometric catalogue of Subaru/Hyper Suprime-Cam (HSC) optical imaging observations at around the North Ecliptic Pole (NEP) where the AKARI infrared (IR) satellite conducted a large survey (NEP-Wide survey). The observations cover almost all the NEP-Wide survey field down to the depth of 28.1, 26.8, 26.3, 25.5, and 25.0 mag (5σ) at grizy, respectively. The five-band HSC catalogue contains about 2.6 million objects, and 70 959 AKARI NEP-Wide counterpart sources are identified in the catalogue. We added existing supplementary catalogues from the u band to the far-IR band, and estimated photo-z for the AKARI-HSC sources. We achieved σΔz/(1 + zs) = 0.06 and an outlier rate of 13.4 per cent at z = 0.2–1.5. Using the spectral energy distribution (SED) template fitting, we classified the AKARI-HSC galaxies into four categories, namely quiescent, star-forming, Type1 active galactic nucleus (AGN), and Type2 AGN, in each redshift bin. Then, at z > 1, the mean SED of star-forming galaxies in mid-IR (3–10 μm) range is significantly different from that of spiral galaxies in the nearby Universe, indicating that many of star-forming galaxies at z > 1 contain a heat source capable of heating dust to temperatures that radiate thermal emission in the mid-IR range. Furthermore, we estimated the number fraction of AGNs (fAGN) in each bin of redshift and IR luminosity (L_IR), and examined the dependence of redshift and L_IR. In log(L_IR/L_⊙) = 11.0–14.0, the fAGN shows a significant increase with increasing redshift, regardless of the LIR bins. In contrast, the fAGN shows a slight increase against L_IR at z < 1 and no increase with increasing L_IR at z > 1.

• Research Organization: SLAC National Accelerator Lab., Menlo Park, CA (United States)
• Sponsoring Organization: USDOE Office of Science (SC), Basic Energy Sciences (BES); Japan Society for the Promotion of Science (JSPS); Ministry of Science and Technology of Taiwan (MOST); National Aeronautics and Space Administration (NASA)
• Grant/Contract Number: AC02-76SF00515; 23244040; 107-2119-M-001-026; 108-2628-M-007-004-MY3; 105-2112-M-007-003-MY3
• OSTI ID: 1767158
• Journal Information: Monthly Notices of the Royal Astronomical Society, Vol. 500, Issue 4; ISSN 0035-8711
• Publisher: Royal Astronomical Society
• Country of Publication: United States
• Language: English

Related Subjects

79 ASTRONOMY AND ASTROPHYSICS
evolution of galaxies
photometry
starburst
star formation
infrared