skip to main content

SciTech ConnectSciTech Connect

Title: Relative astrometry of compact flaring structures in Sgr A* with polarimetric very long baseline interferometry

We demonstrate that polarimetric interferometry can be used to extract precise spatial information about compact polarized flares of Sgr A*. We show that, for a faint dynamical component, a single interferometric baseline suffices to determine both its polarization and projected displacement from the quiescent intensity centroid. A second baseline enables two-dimensional reconstruction of the displacement, and additional baselines can self-calibrate using the flare, enhancing synthesis imaging of the quiescent emission. We apply this technique to simulated 1.3 mm wavelength observations of a 'hot spot' embedded in a radiatively inefficient accretion disk around Sgr A*. Our results indicate that, even with current sensitivities, polarimetric interferometry with the Event Horizon Telescope can achieve ∼5 μas relative astrometry of compact flaring structures near Sgr A* on timescales of minutes.
Authors:
;  [1] ;  [2] ;  [3] ;  [4] ;  [5]
  1. Harvard-Smithsonian Center for Astrophysics, 60 Garden Street, Cambridge, MA 02138 (United States)
  2. Haystack Observatory, Massachusetts Institute of Technology, Route 40, Westford, MA 01886 (United States)
  3. Perimeter Institute for Theoretical Physics, 31 Caroline Street North, Waterloo, ON N2L 2Y5 (Canada)
  4. Department of Physics MS-057, Brandeis University, Waltham, MA 02454-0911 (United States)
  5. Arizona Radio Observatory, Steward Observatory, University of Arizona, 933 North Cherry Avenue, Tucson, AZ 85721-0065 (United States)
Publication Date:
OSTI Identifier:
22370384
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 794; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; BLACK HOLES; EMISSION; GALAXIES; INTERFEROMETRY; POLARIZATION; RESOLUTION; SENSITIVITY; SIMULATION; TWO-DIMENSIONAL CALCULATIONS; WAVELENGTHS