Charles F. Gammie

VAPOLA -- A multiyear, multiband polarization survey of AGNs and Sgr A* at millimeter wavelengths with ALMA. II. Spectropolarimetric properties and their evolution from 2017 to 2023

We aim to present a systematic analysis of the spectropolarimetric properties of a sample of 39 active galactic nuclei (AGNs) and Sagittarius A* observed with the Atacama Large Millimeter/submillimeter Array during five VLBI campaigns between 2017 and 2023. We characterized the c...

Ring Position Angles and Spin in M87* and Sgr A*

Event Horizon Telescope (EHT) images of black holes appear as rings with a brightness asymmetry. Here, we expand on our previous study of the asymmetry magnitude a 1 to study the position angle of the peak brightness asymmetry P A 1 in general relativistic magnetohydrodynamic (GR...