Cosmic star-formation history and black hole accretion history inferred from the JWST source counts

Seong Jin KIM^1*, Tomotsugu GOTO^1,2, Chie-Teng LING¹, Cossas K.-W. WU², Tetsuya HASHIMOTO³, Ece KILERCI⁴, Simon HO⁵, Yuri UNO³, Po-Ya WANG¹, Yu-Wei LIN^1,2

¹Institute of astronomy, National Tsing Hua University, Hsinchu, Taiwan
²Department of physics, National Tsing Hua University, Hsinchu, Taiwan
³Department of physics, National Chung Hsing University, Taichung, Taiwan
⁴Faculty of Engineering and Natural Sciences, Sabanci University, Istanbul, Turkey
⁵Research School of Astronomy and Astrophysics, The Australian National University, Canberra, Australia

* Presenter:Seong Jin KIM, email:seongini@gmail.com

With the advent of the James Webb Space Telescope (JWST), we obtained extra-galactic source counts in the mid-infrared (MIR) down to micro-Jy level. This capability reached several tens of times fainter limits than what previous-generation infrared (IR) telescopes achieved in the MIR. In this study, our goal is to interpret/reproduce the JWST source counts and constrain the cosmic star-formation history (CSFH) and black hole accretion history (BHAH). We achieved this by a model-approached way, adopting model luminosity functions (LFs) of galaxies and employing backward evolution of the local LFs (LLFs). The LLFs at the different JWST/MIRI bands were determined using model templates of the spectral energy distributions (SEDs) for five representative galaxy types: star-forming galaxies, starbursts, composites, AGN type 2, and 1. By fitting our model simultaneously to all the source counts in the six MIRI bands, including previous results, we determined the best-fit evolutions of MIR LFs for each of the five galaxy types. Subsequently, we estimated the CSFH and BHAH, which are reasonably consistent with previous works. Thanks to the JWST, our estimates are based on real IR galaxies, several tens of times fainter in the MIR, which have been extrapolations and/or predictions in the previous studies.

Keywords: galaxy, evolution, infrared