Mapping Gas Accretion and Stellar Kinematics to Sub-kiloparsec Scales in NGC 4696 with JWST/NIRSpec
Year: 2026
Type: preprint
Abstract: We present JWST/NIRSpec IFU spectroscopy of the central $618\times618$ pc$^2$ ($\sim3''\times3''$) of NGC 4696, the BCG in the Centaurus cluster. Leveraging the $\sim0.1''$ ($20.6$ pc) pixel size of JWST, we resolve a compact circumnuclear rotating disk (radius of $\sim120$ pc) traced by Pa$α$ and H$_2$ 1$-$0 S(1) emission, which allows a reassessment of the AGN position based on the kinematic centre of this disk. A central Pa$α$ velocity dispersion reaching $σ\sim449$ km s$^{-1}$ implies a SMBH mass of $\sim10^9$ M$_\odot$, corresponding to a sphere of influence of $r_\mathrm{inf}\sim60$ pc, resolved by our observations. Position-velocity diagrams reveal an increase from $\sim-200$ to $\sim600$ km s$^{-1}$ on scales of $\sim150$ pc (a gradient of $4.7$ km s$^{-1}$ pc$^{-1}$) and an accretion rate of $\sim18$ M$_\odot$ yr$^{-1}$ feeding the CND. The Pa$α$ emission shows a double-component in the core, with a high-dispersion redshifted component reaching $σ\sim600$ km s$^{-1}$. In contrast, MUSE H$α$ observations covering the $\sim10$ kpc-scale filamentary structure recover only weak velocity gradients ($\lesssim150$ km s$^{-1}$) within $\sim300\times300$ pc$^2$ and do not resolve the disk due to larger PSFs and pixel sizes. ALMA CO(2-1) data reveal only compact molecular clumps within a $\sim410\times410$ pc$^2$ region, with no extended counterpart to the structures traced by Pa$α$ and H$_2$ 1$-$0 S(1). Stellar kinematics show a smooth velocity field and broad dispersion profile, clearly decoupled from both the multiphase gas and the hot ICM probed by XRISM. These results provide a direct, spatially resolved view of gas dynamics within the inner few hundred parsecs, demonstrating the power of JWST/NIRSpec to probe SMBH feeding.
Source: arXiv (Cornell University)
Authors: Marquis, Mathieu, Hlavacek-Larrondo, Julie, Pereira, Olivia, Reefe, Michael, Choi, Hyunseop, Barrera-Ballesteros, Jorge, Vigneron, Benjamin, Sun, Ming, Canning, Rebecca E. A., Taylor, Gregory, Albert, Loïc, D'Eugenio, Francesco, Donahue, Megan, Fabian, Andrew C., Ferland, Gary J., Gallagher, John S., Gendron-Marsolais, Marie-Lou, Guillard, Pierre, Guo, Minghao, Hatch, Nina, Kotulla, Ralf, Li, Yuan, Maiolino, Roberto, Man, Allison, McDonald, Michael A., McNamara, Brian R., Olivares, Valeria, Prunier, Marine, Reynolds, Christopher S., Rhea, Carter, Richard-Laferrière, Annabelle, Russell, Helen R., Salomé, Philippe, Tamhane, Prathamesh, Thilloy, Auriane, Tremblay, Grant R., Voit, G. Mark, Walker, Stephen A.
Institutions: Université de Montréal, Massachusetts Institute of Technology, University of Michigan, Michigan State University, University of Cambridge, University of Kentucky, Université Laval, Centre National de la Recherche Scientifique, Institut d'Astrophysique de Paris, Sorbonne Université, Princeton University, University of Nottingham, University of Wisconsin–Madison, University of Massachusetts Amherst, University of British Columbia, Universidad de Santiago de Chile, Joint Space Science Institute, University of Maryland, College Park, Université Paris Sciences et Lettres, Observatoire de Paris, Laboratoire d’Etudes du Rayonnement et de la Matière en Astrophysique et Atmosphères, Center for Astrophysics Harvard & Smithsonian, Centre for Research in Astrophysics of Québec, University of Alabama in Huntsville
Language: English
Subfield: Astronomy and Astrophysics
Field: Physics and Astronomy
Domain: Physical Sciences
Open Access status: green
Funders: National Science Foundation, National Aeronautics and Space Administration, Space Telescope Science Institute, Canada Research Chairs, Université de Montréal, Canadian Space Agency, Natural Sciences and Engineering Research Council of Canada, Dirección General de Asuntos del Personal Académico, Universidad Nacional Autónoma de México
Awards: G103270039, G1338664626, G143494905, G256731684, CAREER: Modeling the Evolution of Massive Galaxies with Enzo-E, Graduate Research Fellowship Program (GRFP), G5568641063, G5681601665, Collaborative Research: Simulations and Synthetic Observations of the Earliest Galaxies and Active Galactic Nuclei, G6671297155, G7090426470, G8101178622
OpenAlex ID: W7222387221