The Wobbling Shadow of the M87* Black Hole
M87* is a supermassive black hole in the center of the M87 galaxy. You may already know it from the first image of a black hole, published by the Event Horizon Telescope Collaboration in 2019 [https://eventhorizontelescope.org/pre...]. This animation presents about three years in the life of M87*, as predicted by numerical simulations. It shows the expected appearance and dynamics of the supermassive black hole as observed with 1.3-millimeter-long light waves used by the EHT. You can see turbulent gas heated to billions of degrees swirling around the event horizon, before finally plunging into the black hole. A sharp bright ring surrounding the black hole shadow is an effect of extremely strong lensing near the so-called photon shell [https://skyandtelescope.org/astronomy...]. Since it’s located over 50 million light years away, M87* appears quite small in the sky, at only about 42 microarcseconds across (42 millionths of 1/60th of 1/60th of 1 degree in angular width). This is 45,000,000 times smaller than the angular diameter of the full Moon! [ • Zooming in to the Heart of Messier 87 ] For that reason, the EHT can’t see sharp images of the source. The blurred portion of the animation corresponds to the effective resolution of the EHT. The dashed black ring measures 42 microarcseconds in diameter. The clock hand indicates the position of the bright side of the fitted crescent. We expect that the bright side should be most of the time located in the bottom of the image, where the velocity of the rotating gas is pointed in the observer’s direction. However, because of the turbulence, the fitted position angle varies quite a bit - the crescent wobbles. By studying the time-variability of the M87* image with the EHT, we can learn about the physics of matter in an extreme environment very near the event horizon, and understand the relations between the black hole and the accretion flow surrounding it. You’ll find out more about the wobbling M87* crescent in our upcoming paper, to be published on September 23rd, 2020. Animation credit: G. Wong, B. Prather, C. Gammie, J. Farah, M. Wielgus, and the EHT Collaboration Music credit: "Seconds of Love" by Mastrovita: • Mastrovita - Seconds Of Love (Copyright Fr... Credit: EHT #Astronomy #BlackHoles #EventHorizonTelescope
