DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI
Name
Doeleman-2009-DETECTING FLARING ST.pdf
Size
2.19 MB
Format
Adobe PDF
Checksum (MD5)
88fb37148876c4b587be1ee1836f9fa5
Author(s)
Doeleman, Sheperd Samuel
Fish, Vincent L.
Broderick, Avery E.
Loeb, Abraham
Rogers, Alan E. E.
Date Issued
April 2009
Journal
Astrophysical Journal
Publisher
Institute of Physics/American Astronomical Society
Citation
Doeleman, Sheperd S., Vincent L. Fish, Avery E. Broderick, Abraham Loeb, and Alan E. E. Rogers. “DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI.” The Astrophysical Journal 695, no. 1 (March 27, 2009): 59–74. © 2009 American Astronomical Society.
Version
Final published version
Abstract
The super-massive black hole candidate, Sagittarius A*, exhibits variability from radio to X-ray wavelengths on timescales that correspond to <10 Schwarzschild radii. We survey the potential of millimeter wavelength very long baseline interferometry (VLBI) to detect and constrain time-variable structures that could give rise to such variations, focusing on a model in which an orbiting hot spot is embedded in an accretion disk. Nonimaging algorithms are developed that use interferometric closure quantities to test for periodicity, and applied to an ensemble of hot spot models that sample a range of parameter space. We find that structural periodicity in a wide range of cases can be detected on most potential VLBI arrays using modern VLBI instrumentation. Future enhancements of millimeter/submillimeter VLBI arrays including phased-array processors to aggregate VLBI station collecting area, increased bandwidth recording, and addition of new VLBI sites all significantly aid periodicity detection. The methods described herein can be applied to other models of Sagittarius A*, including jet outflows and magnetohydrodynamic accretion simulations.
MIT Department
Haystack Observatory
Terms of Use
Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use.
Persistent DSpace Link
DOI of Published Version
https://doi.org/10.1088/0004-637x/695/1/59
