These connections between active supermassive black holes–specifically, the activities driven by their active galactic nuclei–play a critical role in our understanding the origins of modern galaxies. Both jets and winds can cut off star formation–both near their paths and much farther afield by heating up the galaxies’ gas. Gas and dust sent flying away from the galaxies in the form of jets can travel well beyond the galaxies’ star-filled arms. (Material that falls into the black holes is not in this mix–only the gas and dust that is just outside their event horizons.) Some of this material is ejected along incredibly strong magnetic fields into jets and winds. The particles in these ever-rotating accretion disks near black holes periodically rub together, creating heat and light. One reason we know so much about active galactic nuclei is through studies of the gas and dust that orbit supermassive black holes (which are known as accretion disks). How we detect active supermassive black holes–and what NASA’s James Webb Space Telescope will help researchers reveal. (We now know their bright active galactic nuclei are also surrounded by galaxies, but the galaxies’ light is difficult to differentiate from the quasars’ light.) First, the Basics Quasars, whose name is derived from the term “quasi-stellar radio sources,” are very distant, point-like sources–which is why they received this slightly misleading moniker. The differences between these groups begin with their distances from Earth: Seyfert galaxies are nearby, which means we can also easily see and study the galaxies that surround their active galactic nuclei. The formal term active galactic nuclei, which is admittedly less than catchy, applies to several additional classifications that do grab attention, including quasars (also known as radio galaxies) and blazars, and Seyfert galaxies. Credit: NASA, ESA, and the Hubble SM4 ERO Team. Get the full video details on HubbleSite. Powerful magnetic fields keep the material confined to an extragalactic jet. Some of the superheated material escapes along the black hole’s rotation axis. An accretion disk of infalling material surrounds a central black hole that may be millions or billions of times the mass of our sun. This animation of an active galactic nucleus provides a close-up look at the behavior of a central black hole in an active galaxy.
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