Undermassive Hosts of $z = 4-6 $ AGN from JWST/NIRCam Image Decomposition with CONGRESS, FRESCO, and JADES

Fuente: arXiv
Saved in:
Bibliographic Details
Main Authors: Ma, Zheng, Egami, Eichi, Zhu, Yongda, Sun, Fengwu, Lyu, Jianwei, Zhang, Junyu, Willmer, Christopher N. A., Bunker, Andrew J., Carniani, Stefano, Curtis-Lake, Emma, Hausen, Ryan, Ji, Xihan, Ji, Zhiyuan, Juodžbalis, Ignas, Maiolino, Roberto, Rieke, George H., Rinaldi, Pierluigi, Sun, Yang, Tacchella, Sandro, Übler, Hannah, Williams, Christina C.
Format: Preprint
Published: 2026
Subjects:
Online Access:
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1866915747555442688
author Ma, Zheng
Egami, Eichi
Zhu, Yongda
Sun, Fengwu
Lyu, Jianwei
Zhang, Junyu
Willmer, Christopher N. A.
Bunker, Andrew J.
Carniani, Stefano
Curtis-Lake, Emma
Hausen, Ryan
Ji, Xihan
Ji, Zhiyuan
Juodžbalis, Ignas
Maiolino, Roberto
Rieke, George H.
Rinaldi, Pierluigi
Sun, Yang
Tacchella, Sandro
Übler, Hannah
Williams, Christina C.
author_facet Ma, Zheng
Egami, Eichi
Zhu, Yongda
Sun, Fengwu
Lyu, Jianwei
Zhang, Junyu
Willmer, Christopher N. A.
Bunker, Andrew J.
Carniani, Stefano
Curtis-Lake, Emma
Hausen, Ryan
Ji, Xihan
Ji, Zhiyuan
Juodžbalis, Ignas
Maiolino, Roberto
Rieke, George H.
Rinaldi, Pierluigi
Sun, Yang
Tacchella, Sandro
Übler, Hannah
Williams, Christina C.
contents In the local Universe, supermassive black hole (SMBH) masses strongly correlate with their host-galaxies' stellar masses ($M_{*}$), but galaxies hosting faint AGN recently found by JWST may deviate from this relation. To constrain the M$_{\text{BH}}$-M$_{*}$ relation at high redshift, we performed AGN-host image decomposition for 17 low-luminosity AGN galaxies at $z$\,$\sim$\,4--6 using NIRCam images in the JADES GOODS-N field. These sources are identified as AGNs from broad H$α$ emission lines detected by the CONGRESS and FRESCO surveys. We used \textsc{galfit+MCMC} to fit spatial profiles in 7 wide-band images and detected extended emission in 9 sources out of 17. The close spatial alignment between the extended components and the AGN centers indicates that this emission likely originates from the host galaxies. These sources are extended at 0.9--2.0~$μ$m, suggesting significant host-galaxy light in the rest-frame UV. For the sources with the host detection, the stellar mass inferred based on image decomposition result can be 1-2 dex lower than the results without image decomposition. The BH-to-stellar mass ratio spans $M_{\text{BH}}/M_\ast$\,$\sim$\,0.01--1.48, placing them well above the local $M_{\text{BH}}$--$M_\ast$ relation. In contrast, the host-galaxy size--mass relation broadly agrees with previous measurements. Our results suggest that the host galaxies of these faint AGN are either genuinely under-massive compared to their black hole masses, or too compact to be spatially resolved.
format Preprint
id arxiv_https___arxiv_org_abs_2601_15962
institution arXiv
publishDate 2026
record_format arxiv
spellingShingle Undermassive Hosts of $z = 4-6 $ AGN from JWST/NIRCam Image Decomposition with CONGRESS, FRESCO, and JADES
Ma, Zheng
Egami, Eichi
Zhu, Yongda
Sun, Fengwu
Lyu, Jianwei
Zhang, Junyu
Willmer, Christopher N. A.
Bunker, Andrew J.
Carniani, Stefano
Curtis-Lake, Emma
Hausen, Ryan
Ji, Xihan
Ji, Zhiyuan
Juodžbalis, Ignas
Maiolino, Roberto
Rieke, George H.
Rinaldi, Pierluigi
Sun, Yang
Tacchella, Sandro
Übler, Hannah
Williams, Christina C.
Astrophysics of Galaxies
In the local Universe, supermassive black hole (SMBH) masses strongly correlate with their host-galaxies' stellar masses ($M_{*}$), but galaxies hosting faint AGN recently found by JWST may deviate from this relation. To constrain the M$_{\text{BH}}$-M$_{*}$ relation at high redshift, we performed AGN-host image decomposition for 17 low-luminosity AGN galaxies at $z$\,$\sim$\,4--6 using NIRCam images in the JADES GOODS-N field. These sources are identified as AGNs from broad H$α$ emission lines detected by the CONGRESS and FRESCO surveys. We used \textsc{galfit+MCMC} to fit spatial profiles in 7 wide-band images and detected extended emission in 9 sources out of 17. The close spatial alignment between the extended components and the AGN centers indicates that this emission likely originates from the host galaxies. These sources are extended at 0.9--2.0~$μ$m, suggesting significant host-galaxy light in the rest-frame UV. For the sources with the host detection, the stellar mass inferred based on image decomposition result can be 1-2 dex lower than the results without image decomposition. The BH-to-stellar mass ratio spans $M_{\text{BH}}/M_\ast$\,$\sim$\,0.01--1.48, placing them well above the local $M_{\text{BH}}$--$M_\ast$ relation. In contrast, the host-galaxy size--mass relation broadly agrees with previous measurements. Our results suggest that the host galaxies of these faint AGN are either genuinely under-massive compared to their black hole masses, or too compact to be spatially resolved.
title Undermassive Hosts of $z = 4-6 $ AGN from JWST/NIRCam Image Decomposition with CONGRESS, FRESCO, and JADES
topic Astrophysics of Galaxies
url https://arxiv.org/abs/2601.15962