The scientific community has recently announced the discovery of the most distant radio galaxy ever recorded, pinpointed at a staggering distance of 12 billion light-years from our own planet. This groundbreaking revelation came about as a result of data gathered through a sky survey executed by the Giant Metrewave Radio Telescope (GMRT) situated in Pune. The information points to the existence of a galaxy from a period when the universe was just seven percent of its current age, demonstrating that this light has traveled across time and space for almost 12 billion years to reach us.
Measuring Galaxy Distances
The remarkable distance of this newly discovered radio galaxy was established utilizing the Gemini North telescope in Hawaii and the Large Binocular Telescope in Arizona. This study has heightened our understanding of the formation, evolution, and nature of galaxies. Furthermore, it provides crucial insights into the creation of the universe’s earliest black holes. Comparatively, the closest known radio galaxy, Centaurus A, is a mere 10 million light years away from Earth.
The Role of the Giant Metrewave Radio Telescope (GMRT)
The GMRT plays a pivotal role in this achievement. As a large array comprising thirty fully steerable parabolic radio telescopes each with a diameter of 45 meters, it is operated by the National Centre for Radio Astrophysics under the Tata Institute of Fundamental Research. The design of the GMRT is built upon the ‘SMART’ concept – short for Stretch Mesh Attached to Rope Trusses. It functions primarily within the meter wavelength area of the radio spectrum where man-made radio interference is significantly lower. Pune, the location of the GMRT, was specifically chosen for reasons including low radio noise, good communication, proximity to industrial centers, and its northerly latitude offering a quiet ionospheric environment as well as viewability of a majority of the southern sky.
Understanding Radio Galaxies
Radio galaxies are astronomical rarities, characterized by their enormous size and the presence of a supermassive black hole at the center, which actively accumulates gas and dust from the surrounding space. A black hole is a region in space with gravity so intense that it prevents even light from escaping. The strong gravitational pull occurs as a result of matter being compacted into an incredibly small area, usually following the death of a star. This mass accumulation triggers the launch of high-energy jet streams capable of accelerating charged particles near the black hole to almost the speed of light. These jets are clearly visible at radio wavelengths.
All about Quasars
Quasars and radio galaxies are among the brightest objects in the universe. The term ‘quasar’ stands for “quasi-stellar radio source,” referring to its stellar-like emission of radio waves. However, it’s important to note that most quasars are actually faint radio emitters. Apart from radio waves and visible light, quasars emit ultraviolet rays, infrared waves, X-rays, and gamma-rays. Many surpass the size of our own solar system, adding further intrigue to the study of these celestial bodies.
