She Uses ‘echoes’ Like A Bat

“They’re not just ornamental. They’re not just sitting there passively,” Kara says. “They’re actually dictating how the galaxy evolves and why the galaxy looks the way that it does.”

An observational astrophysicist at the Massachusetts Institute of Technology, Erin Kara visits mind-bending territory. Like an astronaut in the film Interstellar, she explores the regions near gargantuan black holes. Her goal is to better understand how those black holes behave and how they continually reshape galaxies across the universe.

Packed with mass equal to millions or billions of suns, supermassive black holes lurk at the center of nearly every galaxy. Energetically, these black holes are like galaxies’ dark, beating hearts.

Kara tries to understand the environment near these black holes, where most of their energy is released. By carefully tracking the gas and plasma that swirls near a black hole — forming what’s known as an accretion disk — she can approximate the black hole’s mass, for example. That nearby gas and plasma can also help reveal how feasting black holes create extreme cosmic structures such as relativistic jets — gigantic beams of superheated plasma accelerated to nearly the speed of light.