Milky Way: Explosion at the center, 3.5 million years ago

A gigantic, expanding spectre of energy originated from a nearby supermassive black hole in the centre of the Milky Way Galaxy about 3.5 million years ago. The explosion released cone-shaped radiation through both poles of the Galaxy and also out into deep space.

A research headed by Professor Joss Bland-Hawthorn from Australia’s ARC Centre of Excellence for All-Sky Astrophysics in 3 Dimension (ASTRO 3D) released the information. the research is soon to be published in The Astrophysical Journal.

Seyfert Flare

As reported, the phenomenon is known as a Seyfert flare. It creates two enormous ‘ionisation cones’(ion radiation) that crosses through the Milky Way. The process begins with a relatively small diameter very close to the black hole which further expands to a very huge size and then slices through the Galaxy. The radiation was so powerful that it impacted the Magellanic Stream. Magellanic Clouds are a long trail of gas extending from nearby dwarf galaxies. They can be of very large as well as of very small size. The Magellanic Stream of clouds lies at an average distance of 200,000 light-years from the Milky Way.

According to the research, the explosion was too gigantic, The incident could be compared to any nuclear activity associated with the black hole. Such activities are known as Sagittarius A or Sgr A*. They are about 4.2 million times more massive than the Sun.

According to professor Bland-Hawthorn, “The flare must have been a bit like a lighthouse beam”. He also explained it as, “Imagine darkness, and then someone switches on a lighthouse beacon for a brief period of time.”

Hubble Space Telescope data puts some light on the history and origin of such events, according to the data, the massive explosion took place, around 3.5 years ago.

If we go through the timeline of events happened on Earth, at that point of time, the asteroid that led to the extinction of the dinosaurs was already 63 million years ago, and human’s ancient ancestors, the Australopithecus, were just developing in Africa.

The spatial area of the Milky Way galaxy is very diverse in its properties. The massive blast took place at the centre of the galaxy, due to this reason the blast was very impactful. The whole event shows that the centre of the Galaxy is very dynamic and highly active. Another insight on the issue is, that the blast lasted for around 300,000 years, which is a very short time in galactic terms. 

The research paper by Professor Bland-Hawthorn was published in 2013. It says that the massive explosion at the centre of the Milky Way ruled out a nuclear starburst as the cause and tentatively tied it to activity in SgrA*.

These results change our understanding of the Milky Way and also makes it clears the fact that there is a lot more left to be discovered. For years it was considered that our Galaxy is static and very inactive, but such findings prove all of us wrong. This new evidence might give a chance to completely reinterpret the possibilities for Milky Way galaxy. 

Sagar Purswani: