The Supermassive Black Hole in the Nearby Spiral Galaxy M81: A Robust Mass from JWST/NIRSpec Stellar Dynamics

The Astrophysical Journal American Astronomical Society 1003:1 (2026) 98

Authors:

Dieu D Nguyen, Tuan N Le, Michele Cappellari, Hai N Ngo, Tinh QT Le, Tien HT Ho, Long QT Nguyen, Elena Gallo, Fan Zou, Michele Perna, Niranjan Thatte, Miguel Pereira-Santaella

Abstract:

Despite its proximity, the mass of the supermassive black hole (SMBH) in the spiral galaxy M81 (NGC 3031) has remained a subject of discussion, with doubts previously cast on the reliability of available dynamical measurements. We present the first robust stellar-dynamics measurement of its mass using high-resolution, two-dimensional kinematics from JWST/NIRSpec observations of the central 3″ × 3″. By tracing stellar motions in the near-infrared, our data penetrate the obscuring nuclear dust and allow for the separation of stellar light from the nonthermal AGN continuum. We modeled the kinematics using the Jeans anisotropic modelling method. Rather than relying on a standard Bayesian approach for error estimation, we constructed a suite of 24 independent models, each employing a unique combination of different physical assumptions regarding stellar mass-to-light (M/L) ratio gradients, the point-spread function, the masking of the central active galactic nucleus, and the orientation of the velocity ellipsoid. This ensemble approach allows us to robustly account for the impact of systematic uncertainties. To estimate our systematic uncertainties, we performed a bootstrap of the MBH values derived from these 24 models, thereby incorporating the variance between different physical assumptions. Our analysis yields a precise SMBH mass of MBH = (4.77 ± 0.37) × 107 M⊙ (1σ confidence, including systematic and statistical uncertainties). This result is consistent with previous determinations within their uncertainties, while providing a crucial and highly reliable anchor point for SMBH–galaxy scaling relations in spiral galaxies.

JADES Data Release 4 – Paper II. Data reduction, analysis, and emission-line fluxes of the complete spectroscopic sample

Monthly Notices of the Royal Astronomical Society Oxford University Press 549:4 (2026) stag939

Authors:

J Scholtz, S Carniani, E Parlanti, F D’Eugenio, E Curtis-Lake, P Jakobsen, AJ Bunker, AJ Cameron, S Arribas, WM Baker, S Charlot, J Chevellard, C Circosta, M Curti, Q Duan, DJ Eisenstein, K Hainline, Z Ji, BD Johnson, GC Jones, N Kumari, R Maiolino, MV Maseda, M Perna, PG Pérez-González, A Saxena

Abstract:

We present the fourth data release of the JWST Advanced Deep Extragalactic Survey (JADES), providing deep spectroscopic observations in the two GOODS fields. A companion paper presents the target selection, spectroscopic redshifts and success rates, and in this paper, we discuss the data reduction and present emission-line flux measurements. The spectroscopy in this work consists of medium-depth, deep, and ultradeep NIRSpec/MSA spectra of 5190 targets, covering the spectral range m and observed with both the low-dispersion prism () and all three medium-resolution gratings (). We describe the data reduction, analysis and description of the data products included in this data release. In total, we measured 3297 robust redshifts out of 5190 targets, spanning a redshift range from up to , including 974 at . This data release includes 1D and 2D fully reduced spectra with 3- and 5-pixel extractions, with slit-loss corrections and background subtraction optimized for point sources. Furthermore, we provide redshifts and SNR > 5 emission-line flux catalogues for the prism and grating spectra, as well as new guidelines to use these data products. Lastly, we are launching a new JADES online data base, designed to enable quick selection and browsing of this data release. Altogether, these data provide the largest statistical sample to date including both PRISM and medium grating spectra across full NIRSpec wavelength range to characterize the properties of galaxy populations across cosmic time.

Jets from a stellar-mass black hole are as relativistic as those from supermassive black holes

Nature Communications Springer Nature (2026)

Authors:

X Zhang, W Yu, F Carotenuto, R Fender, S Motta, A Bahramian, JCA Miller-Jones, TD Russell, S Corbel, PA Woudt, P Atri, C Knigge, GR Sivakoff, AK Hughes, J van den Eijnden, JH Matthews, MC Baglio, P Saikia

Abstract:

Relativistic jets from supermassive black holes in active galactic nuclei are amongst the most powerful phenomena in the universe. Similar jets from stellar-mass black holes offer a chance to study the phenomena on accessible observation time scales. However, such comparative studies across black hole masses and time scales remain hampered by the long-standing perception that stellar-mass black hole jets are in a less relativistic regime. Here, we show the detection of two distinct, relativistic jet ejections from the Galactic black hole X-ray binary 4U 1543−47 during a single outburst, with radio interferometry monitoring observations. Our measurements reveal a likely Lorentz factor of approximately 8 and a minimum of 4.6 at launch with 95% confidence, demonstrating that stellar-mass black holes in X-ray binaries can launch jets as relativistic as those seen in active galactic nuclei.

Spin Demographics of Active Supermassive Black Holes: Updated Estimates from X-Ray Reflection and Future Opportunities

Galaxies MDPI 14:3 (2026) 50

Authors:

Júlia M Sisk-Reynés, Christopher S Reynolds, James H Matthews, Dominic J Walton, Joanna M Piotrowska, James F Steiner, Javier A García, Angelo Ricarte

Abstract:

Understanding the growth of supermassive black holes (SMBHs) requires observational constraints on how their angular momentum—or spin—varies with mass, since the relative importance of coherent accretion, chaotic accretion, and mergers will be reflected in SMBH spin populations. Here we present an updated compilation of reflection-based SMBH spin measurements from the literature and assemble a set of ancillary quantities of interest for each SMBH (including redshift, Eddington ratio, and X-ray luminosity). No obvious apparent correlation between the Eddington-scaled accretion rate and the black hole spin is seen, noting that formal statistical tests are beyond the scope of this review. We discuss the limitations of using this heterogeneous mass–spin sample to test predictions of SMBH growth from semi-analytic models and cosmological simulations, emphasizing the need for a more uniform sample. We then highlight the encouraging prospects enabled by the next-generation NewAthena X-ray flagship observatory. Finally, we summarize how hierarchical Bayesian population inference applied to observed SMBH mass–spin populations will constitute a powerful framework for confirming tentative mass–spin trends in future samples.

A general spectral solver for the axisymmetric Jeans equations: fast dynamical modelling of galaxies with arbitrary anisotropy

Monthly Notices of the Royal Astronomical Society Oxford University Press 549:2 (2026) stag420

Abstract:

Axisymmetric Jeans modelling is widely used to infer galaxy mass profiles from integral-field kinematics, but existing implementations maintain tractability by adopting highly restricted anisotropy prescriptions. I present a new spectral method that solves the axisymmetric Jeans equations as a two-dimensional boundary-value problem. Remarkably, this breaks the traditional trade-off between model flexibility and computational cost, accommodating completely general anisotropy distributions while executing significantly faster than standard restrictive techniques. The method relies on three key choices: (i) solving for the intrinsic dispersion rather than the rapidly varying pressure to improve numerical conditioning; (ii) working in logarithmic radius to efficiently resolve the large dynamic range of galaxies, uniquely matching scale-free (power law) regimes; and (iii) imposing a Robin outer boundary condition that enforces the correct asymptotic decay on a finite computational domain. Orbit integrations in realistic galaxy potentials motivate spherical alignment of the velocity ellipsoid as a physically plausible default, though the framework easily adapts to other alignments. Validated against exact analytic benchmarks – including new analytic Jeans solutions derived herein – the solver recovers intrinsic second moments with high accuracy, showing radially uniform residuals for power-law tests. In practice, it delivers orders-of-magnitude speed-ups over high-accuracy quadrature schemes and is naturally suited to massive GPU parallelization. Released in the public jampy package, this enables the routine application of highly general Jeans models to large surveys and the extensive parameter-space exploration required for rigorous uncertainty quantification.