Indian Scientist lead team found the mission impossible ancient galaxy
AstroSat, India's Astronomy research satellite have been looking into sky since it's launch. It has finally found something that's worth to zip the mouths of people who asks why do we need to spend money on Space Research. Using it's 5 Unique X-ray and UV Telescopes, AstroSat discovered an ancient galaxy currently named as AUDFs01 by detecting a strong UV source of light. The galaxy is approximately 9.3 billion light years away from earth.
Dr Kanak Saha, the lead astronomer from Inter University Centre for Astronomy and AstroPhysics, Pune reported this discovery in Nature Journal. His team includes scientists from various parts of the world including France, United States of America, Japan, France and The Netherlands.
Introduction
Our physical observable Universe began from the known first singularity, The Big Bang. After the explosion, the immediate expansion lead to the cooling of universe which forced the protons and neutrons to settle into atoms and form Hydrogen. This was the Nuclear Fusion of it's first kind which also resulted in the formation of Helium in the first place. As a result of this process, Neutral matter came into existence. It was long after this incidence, such neutral atoms would again become unstable, collide and fuse to form stars. It took dozens of crores of years to form the first star and the very first galaxy. However, there were enough free energy flowing randomly through them which led the other freely existing Hydrogen and Helium atoms to excite and again fuse. This process of ionization is timely recorded as the Epoch of Reionization.
What is Hubble eXtreme Deep Field?
Hubble eXtreme Deep FIeld or shortly known as XDF is the image of a small part of our sky, but created by using 10 years of data from Hubble Telescope. That is, the image is the photograph of our sky, which is a big rendered version of combining the photos taken by NASA's Hubble space telescope for the past 10 years.
What did Astronomer Dr Saha did?
UV radiations do not reach earth's surface because, we humans are being protected from it's harm by our Atmosphere. So, if we need to check for the UV radiations coming from that particular galaxy, we need to settle our eyes above the sky. That's where AstroSat comes into play. Dr Saha and His team just observed a particular galaxy from this XDF and then used INdia's own indigenous Astronomy satellite AstroSat to look at it. Hubble Space telescope was not good at viewing UV images because it was build to record Visible light. However, the Ultraviolet Imaging Telescope (UVIT) on the AstroSat was more victorious to achieve this as it has the best UV telescope India ever made. This helped Dr. Saha to image the galaxy far more smoother than any others could.
Why this discovery is so important?
What Dr. Saha and his team did was to capture a strong extreme source of UV radiation from a distant galaxy. It's very difficult like photographing a single hair from a person's head, who is running along with a crowd. Astronomer's have been looking for such Strong sources of UV, but as the task was almost impossible, no one have found anything valuable yet until Dr. Saha.
What is the greatest mystery behind this discovery?
Though Dr. Saha captured the m inevitable and changed the history of Mission Impossible of astronomy, no one really knows how did that particular source of UV light reached earth. UV radiations would have absorbed by the gaseous particle of the galaxy or any other objects between the earth and the newly found galaxy. But No one really knows how this strange source of radiations reached earth. It's so mysterious as if it was just waiting for us when we looked there.
What is the darkest secret that lies behind these UV light sources?
After the bigbang, universe was still opaque and not transparent because of the unavailability of a radiation source. However this UV source and similar extreme UV sources will reveal how our universe escaped from the darkness of its birth and saw light. For us to study the Bigbang, we need things that existed since then. These UV sources are some reminiscences of those ages. It's a kind of astronomers doing archaeology where these galaxies and UV sources are the leftover fossils.
The article is published and is available at: https://www.nature.com/articles/s41550-020-1173-5
