Quasar host galaxies




Credit: ESO

Quasar (QSO) and its host galaxy

Left: Hubble images of quasar 3C 273. Right: a coronagraph is used to block the quasar's light.                             Credit: NASA and ESA

Most astronomers believe every QSO is powered by a supermassive black hole (SMBH).


Astronomers have concluded that most, if not all, galaxies host MBHs at their centers.



We do not have enough knowledge about QSO host galaxies at redshift > 6. Due to fact that most of the Lyα  emission is absorbed  by IGM.

The emission from redshift 6 galaxies is much smaller than that from redshift 6 QSOs.                                                         (Mortlock et al. 2015)


We obtain 100 high redshift 6 QSOs identified from the SHELLQs All the images were obtained by HSC.  Using these QSOs, we can study the relationship of QSOs and their host galaxies.

(Image credit: National Astronomical Observatory of Japan)

Related publications

1. Unveiling QSO host galaxies and their Lyα emission at z∼6 by SHELLQs

  Simon C.-C. Ho et al., in prep.

2. Subaru High-z Exploration of Low-Luminosity Quasars (SHELLQs) – XV. Constraining the cosmic reionization at 5.5 < z < 7

Ting-Yi Lu, Tomotsugu Goto, Tetsuya Hashimoto, Daryl Joe D Santos, Yi Hang Valerie Wong, Seong Jin Kim, Tiger YY Hsiao, Ece Kilerci, Simon C.-C. Ho et al. 2022, MNRAS, 517, 1

2. Subaru medium-resolution spectra of a QSO at z=6.62: Three ionization tests

  Ting-Yi Lu, Tomotsugu Goto, Ji-Jia Tang, Tetsuya Hashimoto, Yi-Hang Valerie Wong, Chia-Ying Chiang, Yi-Han Wu, Seong Jin Kim, Simon C.-C. Ho et al., 2020, ApJ, 893, 69