Galaxy source counts at 7.7 $\mu$m, 10 $\mu$m and 15 $\mu$m with the James Webb Space Telescope

Abstract

We present mid-infrared galaxy number counts based on the Early Release Observations obtained by the James Webb Space Telescope (JWST) at 7.7-, 10- and 15-$\mu$m (F770W, F1000W and F1500W, respectively) bands of the Mid-Infrared Instrument (MIRI). Due to the superior sensitivity of JWST, the 80 percent completeness limits reach 0.32, 0.79 and 2.0 $\mu$Jy in F770W, F1000W and F1500W filters, respectively, i.e., $\sim$100 times deeper than previous space infrared telescopes such as Spitzer or AKARI. The number counts reach much deeper than the broad bump around $0.05\sim 0.5$ mJy due to polycyclic aromatic hydrocarbon (PAH) emissions. An extrapolation towards fainter flux from the evolutionary models in the literature agrees amazingly well with the new data, where the extrapolated faint-end of infrared luminosity functions combined with the cosmic star-formation history to higher redshifts can reproduce the deeper number counts by JWST. Our understanding of the faint infrared sources has been confirmed by the observed data due to the superb sensitivity of JWST.

6 pages, 8 figures. Accepted for publication in MNRAS

References in corpus (3)

• The James Webb Space Telescope
• High redshift JWST predictions from IllustrisTNG: III. Infrared luminosity functions, obscured star formation and dust temperature of high-redshift galaxies
• The First Source Counts at 18 microns from the AKARI NEP Survey

Cited by in corpus (5)

• Constraining the physical properties of the first lensed $z\sim 10-16$ galaxy candidates with JWST
• Source counts at 7.7 to 21 $\mu$m in CEERS field with James Webb Space Telescope
• Halfway to the Peak: The JWST MIRI 5.6 micron number counts and source population
• The History of Galaxy Mergers in IllustrisTNG
• JWST MIRI color classification of mid-infrared selected galaxies: MIRI color classification toward cosmic noon