Using Millimeter VLBI to Constrain RIAF Models of Sagittarius A*

Abstract

The recent detection of Sagittarius A* at lambda = 1.3 mm on a baseline from Hawaii to Arizona demonstrates that millimeter wavelength very long baseline interferometry (VLBI) can now spatially resolve emission from the innermost accretion flow of the Galactic center region. Here, we investigate the ability of future millimeter VLBI arrays to constrain the spin and inclination of the putative black hole and the orientation of the accretion disk major axis within the context of radiatively inefficient accretion flow (RIAF) models. We examine the range of baseline visibility and closure amplitudes predicted by RIAF models to identify critical telescopes for determining the spin, inclination, and disk orientation of the Sgr A* black hole and accretion disk system. We find that baseline lengths near 3 gigalambda have the greatest power to distinguish amongst RIAF model parameters, and that it will be important to include new telescopes that will form north-south baselines with a range of lengths. If a RIAF model describes the emission from Sgr A*, it is likely that the orientation of the accretion disk can be determined with the addition of a Chilean telescope to the array. Some likely disk orientations predict detectable fluxes on baselines between the continental United States and even a single 10-12 m dish in Chile. The extra information provided from closure amplitudes by a four-antenna array enhances the ability of VLBI to discriminate amongst model parameters.

Accepted for publication in ApJL

References in corpus (10)

• 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
• Nonthermal Electrons in Radiatively Inefficient Accretion Flow Models of Sagittarius A*
• Three-dimensional MHD Simulations of Radiatively Inefficient Accretion Flows
• Stellar dynamics in the central arcsecond of our galaxy
• An Unambiguous Detection of Faraday Rotation in Sagittarius A*
• An X-ray, IR, and Submillimeter Flare of Sagittarius A*
• The Intrinsic Size of Sagittarius A* from 0.35 cm to 6 cm
• Variability of Sagittarius A* - Flares at 1 Millimeter
• Variable Linear Polarization from Sagittarius A*: Evidence for a Hot Turbulent Accretion Flow

Cited by in corpus (27)

• Hot Accretion Flows Around Black Holes
• Photon Rings around Kerr and Kerr-like Black Holes
• The Submillimeter Bump in Sgr A* from Relativistic MHD Simulations
• 1.3 mm Wavelength VLBI of Sagittarius A*: Detection of Time-Variable Emission on Event Horizon Scales
• Evidence for Low Black Hole Spin and Physically Motivated Accretion Models from Millimeter VLBI Observations of Sagittarius A*
• Sagittarius A* Accretion Flow and Black Hole Parameters from General Relativistic Dynamical and Polarized Radiative Modeling
• BlackHoleCam: fundamental physics of the Galactic center
• The Event Horizon of Sagittarius A*
• Estimating the Parameters of Sgr A*'s Accretion Flow Via Millimeter VLBI
• A General Relativistic Null Hypothesis Test with Event Horizon Telescope Observations of the black-hole shadow in Sgr A*
• Sgr A* and General Relativity
• Testing the No-Hair Theorem with Observations in the Electromagnetic Spectrum. IV. Relativistically Broadened Iron Lines
• Towards the event horizon -- the supermassive black hole in the Galactic Center
• Millimeter Flares and VLBI Visibilities from Relativistic Simulations of Magnetized Accretion onto the Galactic Center Black Hole
• Testing the No-Hair Theorem with Observations of Black Holes in the Electromagnetic Spectrum
• Tilted black hole accretion disc models of Sagittarius A*: time-variable millimetre to near-infrared emission
• A geometric crescent model for black hole images
• Masses of Nearby Supermassive Black Holes with Very-Long Baseline Interferometry
• Testing the No-Hair Theorem with Observations of Black Holes in the Electromagnetic Spectrum
• Probing the innermost accretion flow geometry of Sgr A* with Event Horizon Telescope
• Images of the radiatively inefficient accretion flow surrounding a Kerr black hole: application in Sgr A*
• Fine-scale structure of the quasar 3C 279 Measured with 1.3 mm very long baseline interferometry
• Testing the Accretion Flow with Plasma Wave Heating Mechanism for Sagittarius a* by the 1.3MM Vlbi Measurements
• Quantifying Intrinsic Variability of Sagittarius A* using Closure Phase Measurements of the Event Horizon Telescope
• Reconstruction of Static Black Hole Images Using Simple Geometric Forms
• Magnetised Accretion Discs in Kerr Spacetimes II: Hot Spots
• A Metric for Testing the Nature of Black Holes