Veil of fiery gas revealed around the disc of Milky Way
Context
Recently, scientists have discovered the source of superhot gas surrounding the Milky Way galaxy. While earlier studies identified a gaseous halo around the galaxy, recent observations revealed the hotter gas, emitting faint X-rays and absorbing light from distant quasars.
- Researchers at the Raman Research Institute (RRI), along with collaborators from IIT-Palakkad and Ohio State University, proposed a new model explaining these phenomena.
Relevance:
GS-03 (Science and technology)
About the Discovery
- Gaseous Halo: Earlier studies found a gas sphere around the Milky Way, with temperatures of 2 million Kelvin extending 700,000 light-years. Recent findings revealed an even hotter gas, at 10 million Kelvin, emitting faint X-rays.
- Mechanism Identified: Supernova explosions near and above the Milky Way disc heat the gas and enrich it with heavy elements. The movement of this gas explains both the emission and absorption signals observed.
- Future Research: Faint X-ray signals will be further studied across other frequencies to refine the model and gather additional insights.
What is a Galaxy?
- A galaxy is a huge collection of gas, dust, billions of stars, and their solar systems.
- The galaxy is held together by the gravitational force.
- Earth is the part of the Milky Way Galaxy, which also has a super massive blackhole in the middle.
What is a Black Hole?
- A black hole is defined as a region of spacetime where the gravity is so strong that no matter or electromagnetic energy (e.g., light) can escape it.
- The concept was first given by Albert Einstein in 1915 as the theory of general relativity. However, the term ‘black hole’ was coined in the mid-1960s by American physicist John Archibald Wheeler.
- It predicts that a sufficiently compact mass can deform spacetime to form a black hole.
- The boundary of no escape is called the event horizon.
- A black hole has a great effect on the fate and circumstances of an object crossing it, but it has no locally detectable features according to general relativity.
- Black holes generally belong to two categories:
- One that forms when massive stars die. They range between a few solar masses and tens of solar masses.
- The other category is of supermassive black holes. These range from hundreds of thousands to billions of times that of the sun from the solar system to which Earth belongs.
Supernova:
- A supernova is a massive explosion that occurs when a star reaches the end of its life cycle.
- It is the largest explosion in space and can emit more energy in a few seconds than the sun will radiate in its entire lifetime.
- Recently, James Webb Space Telescope (JWST) captured an image of SN1987A, a supernova that exploded decades ago. It is famously known as ‘String of Pearls’.
