Exploring accretion disk physics and black hole growth with regular monitoring of ultrafast active galactic nucleus winds

Fifteen years of XMM-Newton observations have established that ultrafast highly ionized winds (UFOs) are common in radio-quiet active galactic nucleus (AGN). A simple theory of Eddington-limited accretion correctly predicts the typical velocity (∼0.1c) and high ionization of such winds, with observed flow energy capable of ejecting star-forming gas. An extended XMM-Newton observation of the archetypal UFO PG 1211+143 recently found a more complex flow pattern, suggesting that intensive XMM-Newton observations offer exciting potential for probing the inner accretion disk structure and super-massive black hole (SMBH) growth.