There was a report about a month ago that a Fast Radio Burst (FRB) produced a repeating signal. This is big news because we really don’t know what causes FRBs, and once they have ended it can be difficult to trace their source. But a repeating signal means we can pinpoint their origin and potentially figure out their root cause. It’s no wonder the astronomical community was excited…and skeptical. Most of the FRBs that have been discovered were in archival data – data from past surveys that were given a closer look. Only a few have been seen in real-time, so when...
Gamma rays are the most powerful form of electromagnetic radiation in the universe. With wavelengths as small at atoms, they usually result from the most powerful interactions known, such as the collision of two particles, or the release of energy from the accretion disk of a black hole. But there is another potential source of gamma rays that has not yet been confirmed: Dark Matter. The leading candidate for dark matter is the theorized Weakly Interacting Massive Particle (WIMP), though it is not as wimpy as its namesake suggests, making up 5 times as much mass as the visible matter...
The only reason we can see black holes in the universe is because some of them swallow up gas and dust. This heats up material that is spinning rapidly around the black hole as it falls in (called an accretion disk), and produces massive jets of material due to conservation of angular momentum that can be seen across the universe. The energy released in the jets and the energy given off in the accretion disk are proportional to how much gas and dust is being consumed by the black hole. More matter = more food = more energy released. But...
A few months ago I talked about Astronomers seeing the gas cloud known as G2 passing the central black hole of the Milky Way, called Sagittarius A*, and how we had hoped to watch the black hole destroy it in order to learn about the behaviour of supermassive black holes. As we all sat and watched the passage of the cloud over the course of a few months, we were surprised to find that the cloud remained intact and passed straight by Sag A*. When we last checked in, the leading theory was that the ‘cloud’ actually was a dense...
The thing about black holes is that they are very dense. If we took the entire 2,000,000,000,000,000,000,000,000,000,000 Kg of the Sun (This is the real mass of the Sun) and turned it into a black hole, it would be about 6 Km in diameter. It is theorized that there are around 100 Million Black holes in the Milky Way Galaxy alone. But if they aren’t near a large reservoir of gas and dust, with their small size they are pretty harmless and invisible. The only way we could find them would be through their gravitational influence, which is hard to...
Quasars are Galaxies with incredibly massive Black Holes at their centre. These Black Holes are fuelled by a swirling disc of material that can be ejected in a long jet along their axis of rotation, all due to the conservation of angular momentum. This accretion disc can be so hot that it causes the central region of the Galaxy to shine more brightly than the entire Galaxy of stars surrounding it. A Belgian team using the Very Large Telescope (VLT) studied a population of 93 Quasars spread over Billions of Light-Years, and noticed that the rotation axes of the Quasars...
