The recently employed SARAS-3 Radio Telescope has helped scientists discover characteristics of a highly luminous radio galaxy formed during the Cosmic Dawn, a mere 200 million years post-Big Bang. Researchers have employed this valuable data from SARAS-3 to shed light on the energy output, luminosity, and masses of the first generation of galaxies which were brightly visible in radio wavelengths.
The Findings
The recent insights into the Cosmic Dawn resulted in new understandings concerning the properties of the earliest radio-loud galaxies, fueled by supermassive black holes. Through the findings of SARAS-3, astrophysics of the Cosmic Dawn has shown that sub 3% of the gaseous matter found within early galaxies had been converted into stars. Furthermore, it appears the initial galaxies exhibited a bright radio emission were also strong X-ray emitters, resulting in a heating of cosmic gas within and around these early galaxies.
SARAS-3 Radio Telescope: An Overview
SARAS is an experimental endeavor of the Raman Research Institute (RRI) that aims at high-risk and high-gain outputs. The SARAS-3 was deployed in early 2020 over Dandiganahalli Lake and Sharavathi backwaters, located in Karnataka. The primary goal of SARAS is to design, construct, and deploy a precise radio telescope in India capable of detecting incredibly faint radio wave signals originating from our “Cosmic Dawn” – the time when the first galaxies and stars were formed in our early Universe.
Radio Waves and Radio Telescopes: Unraveling the Basics
Radio waves possess the longest wavelengths in the electromagnetic spectrum, with lengths that range from the size of a football field to larger than our planet. The existence of the radio waves was confirmed by Heinrich Hertz in the late 1880s. The range of the radio spectrum is approximately 3 kilohertz to 300 gigahertz.
On the other hand, Radio telescopes are designed to collect weak radio light waves from various astronomical objects such as stars, galaxies, black holes, and more. These specialized telescopes focus on observing the longest wavelengths of light, which range from 1 millimeter to over 10 meters long. For context, visible light waves are only a few hundred nanometers long, and a nanometer is only 1/10,000th the thickness of a piece of paper. It is interesting to note that we typically refer to radio light by its frequency rather than its wavelength.
Source: TH
