The Inner Jet of the Blazar OJ287

© John Hunter, Dhanya Nair

Most galaxies are thought to host supermassive black holes in their centers, of which approximately 10% are classified as active galactic nuclei (AGN). These AGN differ from their counterparts as they’re actively accreting material leading to emission across the EM spectrum, depending on which component is being observed. Jet studies require the use of radio as most emission mechanisms in this region are non-thermal, such as synchrotron, Compton, and inverse-Compton scattering.

Due to the core-shift phenomena, in which different frequencies penetrate the jets to varying depths, very high-frequency radio vlbi data is needed to image the regions of the jet thought to contain their collimation and acceleration mechanisms. We make use of the Global Millimeter VLBI Array (GMVA) and Very Long Baseline Array (VLBA) to carry out such observations.

Shown above are total intensity maps of the blazar OJ 287 at 15 GHz, 43 GHz, and 86 GHz at roughly similar epochs. In addition, linear polarization vectors are overlaid on the 43 GHz map. These maps, once the remaining polarization vectors are calibrated and plotted, will be used to estimate the Faraday rotation measure in the jet of OJ 287, enabling further studies into the magnetic field structure and strength thought to play a major role in the launching and collimation of its jet.