EIGER III JWST NIRCam observations of the ultra-luminous high-redshift quasar J0100+2802 by Anna-Christina Eilers et al. on Wednesday 30 November

We present the first rest-frame optical spectrum of a high-redshift quasar

observed with JWST/NIRCam in Wide Field Slitless (WFSS) mode. The observed

quasar, J0100+2802, is the most luminous quasar known at $z>6$. We measure the

mass of the central supermassive black hole (SMBH) by means of the rest-frame

optical H$\beta$ emission line, and find consistent mass measurements of the

quasar's SMBH of $M_\bullet\approx10^{10}\,M_\odot$ when compared to the

estimates based on the properties of rest-frame UV emission lines CIV and MgII,

which are accessible from ground-based observatories. To this end, we also

present a newly reduced rest-frame UV spectrum of the quasar observed with

X-Shooter/VLT and FIRE/Magellan for a total of 16.8 hours. We readdress the

question whether this ultra-luminous quasar could be effected by strong

gravitational lensing making use of the diffraction limited NIRCam images in

three different wide band filters (F115W, F200W, F356W), which improves the

achieved spatial resolution compared to previous images taken with the Hubble

Space Telescope by a factor of two. We do not find any evidence for a

foreground deflecting galaxy, nor for multiple images of the quasar, and

determine the probability for magnification due to strong gravitational lensing

with image separations below the diffraction limit of $\Delta\theta\lesssim

0.05''$ to be $\lesssim 2.2\times 10^{-3}$. Our observations therefore confirm

that this quasar hosts a ten billion solar mass black hole less than $1$ Gyr

after the Big Bang, which is challenging to explain with current black hole

formation models.

arXiv: http://arxiv.org/abs/http://arxiv.org/abs/2211.16261v1