Eight New Ultramassive Black Hole Masses Confirm Best Correlation with Galaxy Core Sizes
- 1Universitäts-Sternwarte Muenchen
- 2Max-Planck Institute for Extraterrestrial Physics
Abstract
We analyze black hole (BH) scaling relations at the high-mass end, focusing in particular on the regime of ultramassive black holes, M BH > 10 ¹⁰ M ⊙ (UMBHs). Building on the new dynamical BH mass measurements presented in our companion paper for a sample of 16 brightest cluster galaxies (BCGs), including eight newly identified UMBHs based on triaxial Schwarzschild models, we investigate the implications of these measurements for BH scaling relations. This first sample of triaxial BH mass determinations increases the number of known UMBHs by a factor of 2 and dramatically increases the constraints for BH mass scaling relations at the high-mass end. We find that BCGs are outliers in the canonical M BH ∝ σ ⁴⁻⁵ relation, while the size of their depleted cores—the central light-deficient region—offers a tighter correlation with M BH with a scatter of 0.22 dex in this mass regime, confirming and extending earlier findings that core size provides a robust proxy at the high-mass end. Our measurements smoothly join the trend already established in previous studies. This also holds for tight correlations between core size and sphere-of-influence radius and core size and core density, which, along with the correlation between M BH and core size, strongly support the BH binary model for the formation of the centers of the most massive galaxies, as the observed core sizes are inconsistent with gravitational-wave recoil predictions and the galaxies display central tangential orbital anisotropy expected from scouring.
Related
- The JWST Ultramassive Galaxy Sample -- II. Supermassive Black Hole Masses for 8 Extreme Early-Type Galaxies via Jeans Anisotropic Modelling of High-Resolution Integral-Field NIRSpec Stellar Kinematics
- The JWST Ultramassive Galaxy Sample -- I. Overview, Photometry, and Stellar Kinematics: Selecting Optimal Template Subsets via Non-Negative Matrix Factorization
- Effect of galaxy mergers on dust masses
- JADES: Dynamical Measurements of Dark Matter Halo Masses at z ≈ 7 Using Galaxy Pairs
- Inferring the Dark from the Observable: Estimating Halo Masses Using Galaxy Properties
BibTeX
@article{nicola2026eight,
title = {{Eight New Ultramassive Black Hole Masses Confirm Best Correlation with Galaxy Core Sizes}},
author = {Stefano de Nicola and Jens Thomas and Roberto P. Saglia and Matthias Kluge and Jan Snigula and Ralf Bender},
journal = {The Astrophysical Journal},
year = {2026},
month = nov,
doi = {10.3847/1538-4357/aead96},
url = {https://iopscience.iop.org/article/10.3847/1538-4357/aead96},
note = {CC BY 4.0},
}
RIS
TY - JOUR
TI - Eight New Ultramassive Black Hole Masses Confirm Best Correlation with Galaxy Core Sizes
AU - Stefano de Nicola
AU - Jens Thomas
AU - Roberto P. Saglia
AU - Matthias Kluge
AU - Jan Snigula
AU - Ralf Bender
PY - 2026
DA - 2026/11/06
JO - The Astrophysical Journal
DO - 10.3847/1538-4357/aead96
UR - https://iopscience.iop.org/article/10.3847/1538-4357/aead96
AB - We analyze black hole (BH) scaling relations at the high-mass end, focusing in particular on the regime of ultramassive black holes, M BH > 10 ¹⁰ M ⊙ (UMBHs). Building on the new dynamical BH mass measurements presented in our companion paper for a sample of 16 brightest cluster galaxies (BCGs), including eight newly identified UMBHs based on triaxial Schwarzschild models, we investigate the implications of these measurements for BH scaling relations. This first sample of triaxial BH mass determinations increases the number of known UMBHs by a factor of 2 and dramatically increases the constraints for BH mass scaling relations at the high-mass end. We find that BCGs are outliers in the canonical M BH ∝ σ ⁴⁻⁵ relation, while the size of their depleted cores—the central light-deficient region—offers a tighter correlation with M BH with a scatter of 0.22 dex in this mass regime, confirming and extending earlier findings that core size provides a robust proxy at the high-mass end. Our measurements smoothly join the trend already established in previous studies. This also holds for tight correlations between core size and sphere-of-influence radius and core size and core density, which, along with the correlation between M BH and core size, strongly support the BH binary model for the formation of the centers of the most massive galaxies, as the observed core sizes are inconsistent with gravitational-wave recoil predictions and the galaxies display central tangential orbital anisotropy expected from scouring.
SN - 1538-4357
SN - 0004-637X
ER -