Variable structures in M87* from space, time and frequency resolved interferometry

Abstract

Observing the dynamics of compact astrophysical objects provides insights into their inner workings, thereby probing physics under extreme conditions. The immediate vicinity of an active supermassive black hole with its event horizon, photon ring, accretion disk, and relativistic jets is a perfect place to study general relativity and magneto-hydrodynamics. The observations of M87* with Very Long Baseline Interferometry (VLBI) by the Event Horizon Telescope (EHT) allows to investigate its dynamical processes on time scales of days. Compared to regular radio interferometers, VLBI networks typically have fewer antennas and low signal to noise ratios (SNRs). Furthermore, the source is variable, prohibiting integration over time to improve SNR. Here, we present an imaging algorithm that copes with the data scarcity and temporal evolution, while providing uncertainty quantification. Our algorithm views the imaging task as a Bayesian inference problem of a time-varying brightness, exploits the correlation structure in time, and reconstructs a $2+1+1$ dimensional time-variable and spectrally resolved image at once. We apply this method to the EHT observation of M87* and validate our approach on synthetic data. The time- and frequency-resolved reconstruction of M87* confirms variable structures on the emission ring. The reconstruction indicates extended and time-variable emission structures outside the ring itself.

32 pages, 17 figures, 6 tables

References in corpus (8)

• First M87 Event Horizon Telescope Results. I. The Shadow of the Supermassive Black Hole
• First M87 Event Horizon Telescope Results. VI. The Shadow and Mass of the Central Black Hole
• First M87 Event Horizon Telescope Results. IV. Imaging the Central Supermassive Black Hole
• First M87 Event Horizon Telescope Results. V. Physical Origin of the Asymmetric Ring
• First M87 Event Horizon Telescope Results. II. Array and Instrumentation
• First M87 Event Horizon Telescope Results. III. Data Processing and Calibration
• Dynamical Imaging with Interferometry
• Reconstruction of signals with unknown spectra in information field theory with parameter uncertainty

Cited by in corpus (41)

• First Sagittarius A* Event Horizon Telescope Results. IV. Variability, Morphology, and Black Hole Mass
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• Key Science Goals for the Next-Generation Event Horizon Telescope
• Images and photon ring signatures of thick disks around black holes
• Reference Array and Design Consideration for the next-generation Event Horizon Telescope
• The Photon Ring in M87*
• Adaptive Analytical Ray Tracing of Black Hole Photon Rings
• Multi-frequency Black Hole Imaging for the Next-Generation Event Horizon Telescope
• When models fail: an introduction to posterior predictive checks and model misspecification in gravitational-wave astronomy
• Re-Envisioning Numerical Information Field Theory (NIFTy.re): A Library for Gaussian Processes and Variational Inference
• Bayesian radio interferometric imaging with direction-dependent calibration
• Horizonless spacetimes as seen by present and next-generation Event Horizon Telescope arrays
• Disentangling the Faraday rotation sky
• The jet and resolved features of the central supermassive black hole of M 87 observed with EHT
• Time-dependent visibility modelling of a relativistic jet in the X-ray binary MAXI J1803-298
• Bayesian self-calibration and imaging in Very Long Baseline Interferometry
• Imaging a ring-like structure and the extended jet of M87 at 86 GHz
• A method for reconstructing the Galactic magnetic field using dispersion of fast radio bursts and Faraday rotation of radio galaxies
• Event-horizon-scale Imaging of M87* under Different Assumptions via Deep Generative Image Priors
• Swarm intelligence for full Stokes dynamic imaging reconstruction of interferometric data
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• A dense dark matter core of the subhalo in the strong lensing system JVAS B1938+666
• Non-parametric Bayesian reconstruction of Galactic magnetic fields using Information Field Theory: The inclusion of line-of-sight information in ultra-high energy cosmic ray backtracking
• Interpolation techniques for reconstructing Galactic Faraday rotation
• Probing circular polarization and magnetic field structure in AGN
• Inferring Evidence from Nested Sampling Data via Information Field Theory
• Bayesian Multi-wavelength Imaging of the LMC SN1987A with SRG/eROSITA
• Latent-space Field Tension for Astrophysical Component Detection An application to X-ray imaging
• DoG-HiT: A novel VLBI Multiscale Imaging Approach
• A Bayesian Method for Air-Shower Reconstruction using Information Field Theory
• Towards a Field Based Bayesian Evidence Inference from Nested Sampling Data