Time Domain Filtering of Resolved Images of Sgr A*
arXiv:1708.02577 · doi:10.3847/1538-4357/aa82b7
Abstract
The goal of the Event Horizon Telescope (EHT) is to provide spatially resolved images of Sgr A*, the source associated with the Galactic Center black hole. Because Sgr A* varies on timescales short compared to an EHT observing campaign, it is interesting to ask whether variability contains information about the structure and dynamics of the accretion flow. In this paper, we introduce "time-domain filtering", a technique to filter time fluctuating images with specific temporal frequency ranges, and demonstrate the power and usage of the technique by applying it to mock millimeter wavelength images of Sgr A*. The mock image data is generated from General Relativistic Magnetohydrodynamic (GRMHD) simulation and general relativistic ray-tracing method. We show that the variability on each line of sight is tightly correlated with a typical radius of emission. This is because disk emissivity fluctuates on a timescale of order the local orbital period. Time-domain filtered images therefore reflect the model dependent emission radius distribution, which is not accessible in time-averaged images. We show that, in principle, filtered data have the power to distinguish between models with different black hole spins, different disk viewing angles, and different disk orientations in the sky.
arXiv comment13 pages, 9 figures, accepted for publication in ApJ
References in corpus (60)
- Advection-Dominated Accretion: A Self-Similar Solution
- Measuring Distance and Properties of the Milky Way's Central Supermassive Black Hole with Stellar Orbits
- Event-horizon-scale structure in the supermassive black hole candidate at the Galactic Centre
- HARM: A Numerical Scheme for General Relativistic Magnetohydrodynamics
- Near-infrared flares from accreting gas around the supermassive black hole at the Galactic Centre
- Rapid X-ray flaring from the direction of the supermassive black hole at the Galactic Centre
- GRMHD Simulations of Magnetized Advection Dominated Accretion on a Non-Spinning Black Hole: Role of Outflows
- Jet Launching Structure Resolved Near the Supermassive Black Hole in M87
- Magnetically Driven Accretion Flows in the Kerr Metric I: Models and Overall Structure
- Primitive Variable Solvers for Conservative General Relativistic Magnetohydrodynamics
- Radiative Models of Sgr A* from GRMHD Simulations
- An Improved Distance and Mass Estimate for Sgr A* from a Multistar Orbit Analysis
- High Resolution Linear Polarimetric Imaging for the Event Horizon Telescope
- Direct calculation of the radiative efficiency of an accretion disk around a black hole
- Assessing Quantitative Results in Accretion Simulations: From Local to Global
- Resolved Magnetic-Field Structure and Variability Near the Event Horizon of Sagittarius A*
- An X-ray, IR, and Submillimeter Flare of Sagittarius A*
- An Extension of the Athena++ Code Framework for GRMHD Based on Advanced Riemann Solvers and Staggered-Mesh Constrained Transport
- 1.3 mm Wavelength VLBI of Sagittarius A*: Detection of Time-Variable Emission on Event Horizon Scales
- A public code for general relativistic, polarised radiative transfer around spinning black holes
- Evidence for X-ray synchrotron emission from simultaneous mid-IR to X-ray observations of a strong Sgr A* flare
- A Chandra/HETGS Census of X-ray Variability From Sgr A* During 2012
- Evidence for Low Black Hole Spin and Physically Motivated Accretion Models from Millimeter VLBI Observations of Sagittarius A*
- Testing General Relativity with the Shadow Size of Sgr A*
- Simulating the Emission and Outflows from Accretion Disks
- A near-IR variability study of the Galactic black hole: a red noise source with no detected periodicity
- Observational appearance of inefficient accretion flows and jets in 3D GRMHD simulations: Application to Sgr~A*
- A Constant Spectral Index for Sagittarius A* During Infrared/X-ray Intensity Variations
- The Power of Imaging: Constraining the Plasma Properties of GRMHD Simulations using EHT Observations of Sgr A*
- Plasma diagnostic potential of 2p4f in N -- accurate wavelengths and oscillator strengths
- Estimating the Parameters of Sgr A*'s Accretion Flow Via Millimeter VLBI
- X-ray hiccups from SgrA* observed by XMM-Newton. The second brightest flare and three moderate flares caught in half a day
- A General Relativistic Null Hypothesis Test with Event Horizon Telescope Observations of the black-hole shadow in Sgr A*
- grmonty: a Monte Carlo Code for Relativistic Radiative Transport
- Radio and Millimeter Monitoring of Sgr A*: Spectrum, Variability, and Constraints on the G2 Encounter
- Simultaneous Multi-Wavelength Observations of Sgr A* during 2007 April 1-11
- Magnetorotational Turbulence and Dynamo in a Collisionless Plasma
- Modeling Seven Years of Event Horizon Telescope Observations with Radiatively Inefficient Accretion Flow Models
- Variable Linear Polarization from Sagittarius A*: Evidence for a Hot Turbulent Accretion Flow
- An 8 hour characteristic time-scale in submillimetre light curves of Sagittarius A*
- Persistent Asymmetric Structure of Sagittarius A* on Event Horizon Scales
- GRMHD simulations of accretion onto Sgr A*: How important are radiative losses?
- Saturation of the magnetorotational instability in the unstratified shearing box with zero net flux: convergence in taller boxes
- Probing the magnetic field structure in Sgr A* on Black Hole Horizon Scales with Polarized Radiative Transfer Simulations
- Simultaneous NIR/sub-mm observation of flare emission from SgrA*
- Fast Variability and mm/IR flares in GRMHD Models of Sgr A* from Strong-Field Gravitational Lensing
- Global GRMHD Simulations of Black Hole Accretion Flows: a Convergence Study
- An Extended Magnetohydrodynamics Model for Relativistic Weakly Collisional Plasmas
- A Monte Carlo Code for Relativistic Radiation Transport Around Kerr Black Holes
- Concurrent X-ray, near-infrared, sub-millimeter, and GeV gamma-ray observations of Sgr A*
- Evolution of Accretion Discs around a Kerr Black Hole using Extended Magnetohydrodynamics
- Imaging an Event Horizon: Mitigation of Source Variability of Sagittarius A*
- Near-Infrared and X-ray Quasi-Periodic Oscillations in Numerical Models of Sgr A*
- Resolution Dependence of Magnetorotational Turbulence in the Isothermal Stratified Shearing Box
- HEROIC: 3D General Relativistic Radiative Postprocessor with Comptonization for Black Hole Accretion Discs
- A power-law break in the near-infrared power spectrum of the Galactic center black hole
- GRMHD simulations of visibility amplitude variability for Event Horizon Telescope images of Sgr A*
- Variability in GRMHD simulations of Sgr A: Implications for EHT closure phase observations
- Submillimeter Quasi-Periodic Oscillations in Magnetically Choked Accretion Flows Models of Sgr A*
- Flares and variability from Sagittarius A*: five nights of simultaneous multi-wavelength observations
Cited by in corpus (9)
- Hot Atmospheres, Cold Gas, AGN Feedback and the Evolution of Early Type Galaxies: a Topical Perspective
- Black Hole Shadow as a Test of General Relativity: Quadratic Gravity
- Dynamical Imaging with Interferometry
- Mass-ratio and Magnetic Flux-Dependence of Modulated Accretion from Circumbinary Disks
- Silhouettes of invisible black holes
- Black hole Spin Measurement Based on Time-domain VLBI Observations of Infalling Gas Cloud
- Production of intense episodic Alfvén pulses: GRMHD simulation of black hole accretion disks
- Relativistic Reflection Modeling in AGN and Related Variability from PCA: A Brief Review
- Visible shapes of black holes M87* and SgrA*