Why In News ?
Scientists have uncovered an important clue on how the dark ages of the Universe ended and how the first extreme-UV light appeared.
What is Extreme UV light ?
- They are high-energy ultraviolet radiation is electromagnetic radiation in the part of the electromagnetic spectrum spanning wavelengths from 124 nm down to 10 nm.
- Extreme Ultraviolet (EUV) Light (10-100nm) can only travel through a vacuum, and is completely absorbed in Earth’s atmosphere.
- EUV radiation ionizes the upper atmosphere, creating the ionosphere.
- Since solar EUV waves cannot penetrate the atmosphere, scientists must measure them using rockets and satellites.
Importance of EUV
- India’s first multi-wavelength satellite, AstroSat, has detected extreme-UV (EUV) light from a galaxy, called AUDFs01, 9.3 billion light-years away from Earth.
- Such EUV radiation has enough energy to ionize a hydrogen atom by liberating its electron from the nucleus’s influence.
- EUV photons emitted by galaxies like AUDFs01 could play a crucial role in reionizing the early universe soon after the Cosmic Dark Age and emitting the first light.
- Also this extreme UV wavelength regime is crucial to understand models of the stellar population, especially the massive, hot stars in early galaxies.
- Studying galaxies like AUDFs01 and many more, we could get an idea of how star formation rate, gas consumption rate, and growth of stellar mass in those primitive galaxies.
Ultra Violet Radiations
- UV (Ultraviolet) Light refers to the region in the electromagnetic spectrum between visible light and X-rays
- It has a wavelength falling between 400 and 10 nanometers.
- It is not visible to the human eye, because it has Shorter wavelength, Higher frequency than the light our brain perceives as images.
- In other words light with a wavelength immediately shorter than any light in the visible spectrum is called Ultraviolet Light.
- Red is the light with the longest wavelength, and Violet is the light with the shortest wavelength.
Source : PIB
Topic
GS III : Awareness in the fields of IT, Space, Computers, robotics, nano-technology, bio-technology and issues relating to intellectual property rights
Current Affairs Compilation : 2 October 2020