It is quite challenging to measure the spin of a black hole, especially when it is hard to see them. However, astronomers have found a way to do it. They have measured the spins of 5 supermassive black holes by using a combination of data from gravitational lensing and the Chandra X-ray Observatory. They also made the most out of the gravity of celestial bodies in order to magnify very distant objects.
How did they do it?
Scientists used an in-between galaxy to take the images of quasars with black holes. The Chandra X-ray Observatory gave them a sharp image that separated the many pictures that resulted from the lensing effect. After this, the next step they took into account was to use microlensing – magnification using the individual stars from the galaxy. This way, they had help in detecting the spin of a particular black hole. If the region that emitted x-ray was smaller, it was more likely for them to find out that a black hole was turning at a breakneck pace.
In some of the cases, the holes are spinning very fast. Let us take a clear example: the hole from one quasar, called Einstein Cross, was spinning as fast as it could in theory – 70% the speed of light. All the others were spinning at half of that rate.
They have excellent insight into the spinning black holes
There are not many possibilities to see something like this. If we are to take a look at the theories, gravitational lensing requires an ideal alignment. The team behind this specific study has researched very far quasars, that were up to 10.9 billion light-years away. They can come up with excellent insight into some particular objects that are elusive in their own nature.
Karen and her husband live on a plot of land in British Columbia. They aim to grow and raise a significant part of their food by maintaining a vegetable garden, keeping a flock of backyard chickens and foraging. They are also currently planning a move to a small cabin they hand built. Karen’s academic background in nutrition made her care deeply about real food and seek ways to obtain it. Thus sprung Anna’s interest in backyard gardening, chicken and goat keeping, recycling and self-sufficiency.