Priyambada Natarajan
Appearances
Short Wave
Why Black Holes Are More Than They Seem
They're often seen as sort of cosmic vacuum cleaners. Just sucking in all the material, gas and stars that stray close.
Short Wave
Why Black Holes Are More Than They Seem
And M87... Harbors a supermassive black hole that's like 6 billion times the mass of the sun. And it has a huge jet that's coming out that extends all the way and whose origin we can actually link to the black hole itself.
Short Wave
Why Black Holes Are More Than They Seem
We believe that black holes are spinning because of the way in which material accretes onto them.
Short Wave
Why Black Holes Are More Than They Seem
They swirl less. That's why it's able to swirl all the way in. But there's angular momentum that you get and that spins a black hole. Plus, we also know that's one way black holes grow. So the spin is a consequence, we believe, of how black holes actually assemble and grow in mass.
Short Wave
Why Black Holes Are More Than They Seem
So by the time I was in graduate school, we already knew that the primary mechanism for jet production in black holes arises from sort of the interaction of strong magnetic fields with the spinning black hole.
Short Wave
Why Black Holes Are More Than They Seem
where the rotation of the black hole kind of twists and amplifies these magnetic field lines and pushing and propelling charged particles along the poles of the black hole into these powerful jets. And this process is often referred to as the Blanford-Znaik mechanism. And that's Roger, one of those names. Absolutely.
Short Wave
Why Black Holes Are More Than They Seem
It's just really beautiful because it combines these two very deep and profound ideas and shows you how energy can actually be extracted. But all of this is really hard to observe.
Short Wave
Why Black Holes Are More Than They Seem
But... What is counterintuitive is that we do see very powerful jets of material that are actually expelled from them as well.
Short Wave
Why Black Holes Are More Than They Seem
They're as up close as we can possibly get to a black hole's event horizon. You're able to see where the jet starts. And so that is pretty unprecedented.
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Why Black Holes Are More Than They Seem
We now believe that these black hole jets are critical and they sort of modulate the formation of stars in the galaxy itself. So they become sources of energy and produce, they add heat to the gas. They prevent stars from forming by, and they prevent cooling. So you don't form stars. So they act as a weird sort of, you know, interestingly, like a piston, if you will, of how many stars will form.
Short Wave
Why Black Holes Are More Than They Seem
And so they appear to be shaping the morphology, so how stars are formed, where they form in galaxies, and what times they form in. So they seem to be really much more important than we previously believed.