DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI
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 st...
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| Format: | Article |
| Language: | en_US |
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Institute of Physics/American Astronomical Society
2015
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| Online Access: | http://hdl.handle.net/1721.1/96018 https://orcid.org/0000-0003-1941-7458 |
| _version_ | 1826195958236446720 |
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| author | Doeleman, Sheperd Samuel Fish, Vincent L. Broderick, Avery E. Loeb, Abraham Rogers, Alan E. E. |
| author2 | Haystack Observatory |
| author_facet | Haystack Observatory Doeleman, Sheperd Samuel Fish, Vincent L. Broderick, Avery E. Loeb, Abraham Rogers, Alan E. E. |
| author_sort | Doeleman, Sheperd Samuel |
| collection | MIT |
| description | 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. |
| first_indexed | 2024-09-23T10:18:32Z |
| format | Article |
| id | mit-1721.1/96018 |
| institution | Massachusetts Institute of Technology |
| language | en_US |
| last_indexed | 2024-09-23T10:18:32Z |
| publishDate | 2015 |
| publisher | Institute of Physics/American Astronomical Society |
| record_format | dspace |
| spelling | mit-1721.1/960182022-09-30T20:16:00Z DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI Doeleman, Sheperd Samuel Fish, Vincent L. Broderick, Avery E. Loeb, Abraham Rogers, Alan E. E. Haystack Observatory Doeleman, Sheperd Samuel Fish, Vincent L. Rogers, Alan E. E. 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. National Science Foundation (U.S.) 2015-03-13T18:46:21Z 2015-03-13T18:46:21Z 2009-04 2008-07 Article http://purl.org/eprint/type/JournalArticle 0004-637X 1538-4357 http://hdl.handle.net/1721.1/96018 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. https://orcid.org/0000-0003-1941-7458 en_US http://dx.doi.org/10.1088/0004-637x/695/1/59 Astrophysical Journal 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. application/pdf Institute of Physics/American Astronomical Society American Astronomical Society |
| spellingShingle | Doeleman, Sheperd Samuel Fish, Vincent L. Broderick, Avery E. Loeb, Abraham Rogers, Alan E. E. DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI |
| title | DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI |
| title_full | DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI |
| title_fullStr | DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI |
| title_full_unstemmed | DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI |
| title_short | DETECTING FLARING STRUCTURES IN SAGITTARIUS A* WITH HIGH-FREQUENCY VLBI |
| title_sort | detecting flaring structures in sagittarius a with high frequency vlbi |
| url | http://hdl.handle.net/1721.1/96018 https://orcid.org/0000-0003-1941-7458 |
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