Invited Seminars

IIHE invited seminar: Relativistic Jets from Stellar Mass Black Holes in our galaxy

by Prof. Rob Fender (University of Oxford)

G/0-G.0.20 - Neutrino Room (Building G)

G/0-G.0.20 - Neutrino Room

Building G

Astrophysical black holes are the purest manifestations of general relativity, and mark the frontier of our understanding of physics. When accreting gas into their gravitational potential, they can become the most luminous objects in the universe. The most poorly understood aspect of this accretion process is the formation of extremely powerful, highly collimated 'jets' which carry away a large fraction of the liberated gravitational potential energy at relativistic speeds. The most spectacular examples of this process are the supermassive black holes in the centres of giant elliptical galaxies, including M87, the site of the first direct image of a black hole event horizon. However, these supermassive black hole jets are almost frozen in time, and studying how they propagate from the event horizon to their ultimate termination in cluster gas many millions of years later, and how the liberated energy is deposited in the ambient medium, is simply impossible on humanly-accessible timescales.  However, stellar mass black holes, the remnants of the most massive stars which lived fast and died young, pervade space, with an estimated 100 million in our galaxy alone. Some of these stellar mass black holes accrete at a high rate from orbiting binary companion stars, and mimic the relativistic accretion and jet formation observed in supermassive systems like M87. In this talk I will explore how rich new sets of observational data have allowed us to measure the state of the accretion flow at the moment of jet launch, and track the relativistically ejected material all the way to its termination in the interstellar medium on a timescale of one or two years. For the first time we are able to edge towards precise calorimetry of these ejections and connect this to the energy balance at the event horizon at the moment of launch.
About the speaker:
Organized by

Ioana Maris and Steven Lowette