Categories: Black HolesQuestions

Why are there Black Holes in the Middle of Galaxies?

Question: Why are Black Holes in the Middle of Galaxies?

Answer: The black holes you’re thinking of are known as supermassive black holes. Stellar mass black holes are created when a star at least 5 times larger than the Suns out of fuel and collapses in on itself forming a black hole. The supermassive black holes, on the other hand, can contain hundreds of millions of times the mass of a star like our Sun.

Astronomers are now fairly certain that these supermassive black holes are at the heart of almost every galaxy in the Universe. Furthermore, the mass of these black holes is somehow tied to the mass of the rest of the galaxy. They grown in tandem with each other.

When large quantities of material falls into the black hole, it chokes up, unable to get consumed all at once. This “accretion disk” begins to heat up and blaze brightly in many different wavelengths, including X-rays. When supermassive black holes are actively feeding, astronomers call these quasars.

So how do these black holes get there in the first place? Astronomers aren’t sure, but it could be that the dark matter halo that surrounds every galaxy serves to focus and concentrate material as the galaxy was first forming. Some of this material became the supermassive black hole, while the rest became the stars of the galaxy. It’s also possible that the black hole formed first, and collected the rest of the galaxy around it.

Astronomers just don’t know.

Fraser Cain

Fraser Cain is the publisher of Universe Today. He's also the co-host of Astronomy Cast with Dr. Pamela Gay. Here's a link to my Mastodon account.

Recent Posts

A Nebula that Extends its Hand into Space

The Gum Nebula is an emission nebula almost 1400 light-years away. It's home to an…

3 hours ago

41,000 Years Ago Earth’s Shield Went Down

Earth is naked without its protective barrier. The planet's magnetic shield surrounds Earth and shelters…

5 hours ago

Fall Into a Black Hole With this New NASA Simulation

No human being will ever encounter a black hole. But we can't stop wondering what…

6 hours ago

Solar Max is Coming. The Sun Just Released Three X-Class Flares

The Sun is increasing its intensity on schedule, continuing its approach to solar maximum. In…

14 hours ago

New Evidence for Our Solar System’s Ghost: Planet Nine

Does another undetected planet languish in our Solar System's distant reaches? Does it follow a…

1 day ago

NASA Takes Six Advanced Tech Concepts to Phase II

It's that time again. NIAC (NASA Innovative Advanced Concepts) has announced six concepts that will…

1 day ago