Imaging the Black Hole Silhouette of M87: Implications for Jet Formation and Black Hole Spin

Understand

The silhouette cast by the horizon of the supermassive black hole in M87 can now be resolved with the emerging millimeter very-long baseline interferometry (VLBI) capability.

• Despite being ~2000 times farther away than SgrA* (the supermassive black hole at the center of the Milky-Way and the primary target for horizon-scale imaging), M87's much larger black hole mass results in a horizon angular scale roughly half that of SgrA*'s, providing another practical target for direct imaging.
• However, unlike SgrA*, M87 exhibits a powerful radio jet, providing an opportunity to study jet formation physics on horizon scales.
• We employ a simple, qualitatively correct force-free jet model to explore the expected high-resolution images of M87 at wavelengths of 1.3mm and 0.87mm (230GHz and 345GHz), for a variety of jet parameters.