Millions of black holes are speeding around the Milky Way after being kicked at birth

• A new study indicates that speeding black holes are zipping around the Milky Way.
  
• The fast speed of the binary black hole systems are a result of being kicked away at birth by their supernova.
  
• Using the study, scientists estimate that there could be up to 7.5 million high speed black holes in our very own galaxy.
  

Black holes are quite the conundrum as scientists are still trying to determine how they came into being. One theory is that when a massive star collapses upon itself — a supernova — the explosion is so huge that a black hole is born.

A new study in the Monthly Notices of the Royal Astronomical Society indicates that not only are black holes born in supernova explosions but some explosions are so huge that they kick the black holes across the galaxy.

Travelling at speeds greater than 70 kilometers per second — that’s 252,000 kilometers per hour — there might be millions of high speed black holes moving about the Milky Way.

Black holes and stars have something in common

Scientists have already determined that neutron stars, also the result of a supernova explosion, can kicked across vast distances. They call it the Blaauw kick or natal kick.

They surmise that this happens when a supernova explosion is a little lopsided, resulting in what would be perceived as a recoil.

Previous studies show that seven black holes follow the same pattern — binary black hole systems that have been pushed away with natal kicks.

Only they’re slower by a factor of about three or four. Scientists aren’t sure why but theorise that it’s because black holes are denser with a higher mass.

This new study analysed these seven black holes, along with nine others.

They found that 12 out of the 16 were moving at high velocities and, according to their path, were a result of a supernova kicking them them away.

To put that in proportion, the Milky Way is home to at least 10 million black holes that we know of — so an estimated 7.5 million black holes could be spinning and zooming at high speeds in our own galaxy.

Blinking in wait for gravitational waves

Knowing how many binary black holes are whipping around the Milky Way serves a crucial purpose. Scientists will be able to estimate of how many could merge to create gravitational waves that can be detected by LIGO.

Gravitational waves, in themselves, are a recently confirmed phenomenon. These ripples in space-time are a new way to understand how the universe works.

Before September 2015, the only tool that scientists had at their disposal was studying how light travels through space.

See also:
There was a big spark — 75 times brighter than usual — from the black hole at the heart of the Milky Way

ISRO, NASA just spotted a black hole spinning so fast that it could be making space itself rotate

A black hole bigger than the sun is pulling on the fabric of space and time

Our very own black hole in the Milky Way doesn’t quite eat up ‘everything’