TY - JOUR
T1 - Detection of the Low-stellar-mass Host Galaxy of a z ∼ 6.25 Quasar with JWST
AU - Stone, Meredith A.
AU - Lyu, Jianwei
AU - Rieke, George H.
AU - Alberts, Stacey
N1 - Publisher Copyright:
© 2023. The Author(s). Published by the American Astronomical Society.
PY - 2023/8/1
Y1 - 2023/8/1
N2 - We characterize the stellar mass of J2239+0207, a z ∼ 6.25 sub-Eddington quasar (M 1450 = −24.6), using dedicated JWST/NIRCam medium-band observations of a nearby point-spread function star to remove the central point source and reveal the underlying galaxy emission. We detect the host galaxy in two bands longward of the Balmer break, obtaining a stellar mass of ∼1010 M ⊙, more than an order of magnitude less than this quasar’s existing measured [C ii] dynamical mass. We additionally calculate the mass of J2239+0207's central supermassive black hole using JWST/NIRSpec integral field unit observations, and determine that the black hole is ∼15 times more massive than predicted by the local M BH-M * relation, similar to many high-redshift quasars with dynamical masses determined via millimeter-wave line widths. We carefully consider potential selection effects at play, and find that even when z ∼ 6 quasars are compared to a local sample with similarly determined dynamical masses, many of the high-redshift quasars appear to possess overmassive black holes. We conclude z ∼ 6 quasars are likely to have a larger spread about the M BH-M * relation than observed in the local Universe.
AB - We characterize the stellar mass of J2239+0207, a z ∼ 6.25 sub-Eddington quasar (M 1450 = −24.6), using dedicated JWST/NIRCam medium-band observations of a nearby point-spread function star to remove the central point source and reveal the underlying galaxy emission. We detect the host galaxy in two bands longward of the Balmer break, obtaining a stellar mass of ∼1010 M ⊙, more than an order of magnitude less than this quasar’s existing measured [C ii] dynamical mass. We additionally calculate the mass of J2239+0207's central supermassive black hole using JWST/NIRSpec integral field unit observations, and determine that the black hole is ∼15 times more massive than predicted by the local M BH-M * relation, similar to many high-redshift quasars with dynamical masses determined via millimeter-wave line widths. We carefully consider potential selection effects at play, and find that even when z ∼ 6 quasars are compared to a local sample with similarly determined dynamical masses, many of the high-redshift quasars appear to possess overmassive black holes. We conclude z ∼ 6 quasars are likely to have a larger spread about the M BH-M * relation than observed in the local Universe.
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U2 - 10.3847/1538-4357/acebe0
DO - 10.3847/1538-4357/acebe0
M3 - Article
AN - SCOPUS:85168606341
SN - 0004-637X
VL - 953
JO - Astrophysical Journal
JF - Astrophysical Journal
IS - 2
M1 - 180
ER -