VLBA Continuum Observations of NGC 4258: Constraints onan Advection-dominated Accretion Flow
- 20 April 1998
- journal article
- Published by American Astronomical Society in The Astrophysical Journal
- Vol. 497 (2) , L69-L73
- https://doi.org/10.1086/311284
Abstract
We report a 3 sigma upper limit of 220 microJanskys on any 22-GHz continuum emission coincident with the central engine in NGC 4258. If NGC 4258 is powered by an advection-dominated accretion flow, this radio upper limit implies that the inner advection-dominated flow cannot extend significantly beyond about 100 Schwarzschild radii.Comment: 11 pages, 1 figure, to be published in ApJ LetterKeywords
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