%0 Generic %1 citeulike:13640724 %A Johnson, Michael D. %A Loeb, Abraham %A Shiokawa, Hotaka %A Chael, Andrew A. %A Doeleman, Sheperd S. %D 2015 %K imported %T Measuring the Direction and Angular Velocity of a Black Hole Accretion Disk via Lagged Interferometric Covariance %U http://arxiv.org/abs/1505.07870 %X We show that interferometry can be applied to study irregular, rapidly rotating structures, as are expected in the turbulent accretion flow near a black hole. Specifically, we analyze the lagged covariance between interferometric baselines of similar lengths but slightly different orientations. We demonstrate that the peak in the lagged covariance indicates the direction and angular velocity of the flow. Importantly, measuring the direction of the flow as clockwise or counterclockwise on the sky breaks a degeneracy in accretion disk inclinations when analyzing time-averaged images alone. We explore the potential efficacy using three-dimensional, general relativistic magnetohydrodynamic (GRMHD) simulations, and we highlight several baseline pairs for the Event Horizon Telescope (EHT) that are well-suited to this application. These results indicate that the EHT is capable of determining the direction and angular velocity of the emitting material near Sgr A*, even for highly-inclined flows, and they suggest that a rotating flow may even be utilized to improve imaging capabilities.

@misc{citeulike:13640724, abstract = {{We show that interferometry can be applied to study irregular, rapidly rotating structures, as are expected in the turbulent accretion flow near a black hole. Specifically, we analyze the lagged covariance between interferometric baselines of similar lengths but slightly different orientations. We demonstrate that the peak in the lagged covariance indicates the direction and angular velocity of the flow. Importantly, measuring the direction of the flow as clockwise or counterclockwise on the sky breaks a degeneracy in accretion disk inclinations when analyzing time-averaged images alone. We explore the potential efficacy using three-dimensional, general relativistic magnetohydrodynamic (GRMHD) simulations, and we highlight several baseline pairs for the Event Horizon Telescope (EHT) that are well-suited to this application. These results indicate that the EHT is capable of determining the direction and angular velocity of the emitting material near Sgr A*, even for highly-inclined flows, and they suggest that a rotating flow may even be utilized to improve imaging capabilities.}}, added-at = {2019-03-25T08:20:55.000+0100}, archiveprefix = {arXiv}, author = {Johnson, Michael D. and Loeb, Abraham and Shiokawa, Hotaka and Chael, Andrew A. and Doeleman, Sheperd S.}, biburl = {https://www.bibsonomy.org/bibtex/2adf06807af930f71313af578e8e79c25/ericblackman}, citeulike-article-id = {13640724}, citeulike-linkout-0 = {http://arxiv.org/abs/1505.07870}, citeulike-linkout-1 = {http://arxiv.org/pdf/1505.07870}, day = 28, eprint = {1505.07870}, interhash = {2ee3d708db9166e352fe43328858ea5e}, intrahash = {adf06807af930f71313af578e8e79c25}, keywords = {imported}, month = may, posted-at = {2015-06-07 07:21:57}, priority = {2}, timestamp = {2019-03-25T08:20:55.000+0100}, title = {{Measuring the Direction and Angular Velocity of a Black Hole Accretion Disk via Lagged Interferometric Covariance}}, url = {http://arxiv.org/abs/1505.07870}, year = 2015 }