Researchers develop antenna to detect elusive cosmic radiation

Bengaluru: Researchers in Bengaluru have developed a groundbreaking antenna designed to detect the elusive Cosmic Recombination Radiation (CRR), which has never been observed before.

The lightweight antenna, capable of performing sky measurements in the 2.5-4 GHz frequency range — optimal for CRR detection — was developed by Prof Mayuri Rao and Keerthipriya Sathish from the Raman Research Institute, along with Prof Debdeep Sarkar from the Indian Institute of Science.

CRR originates from the early universe during the Epoch of Recombination, a period marked by the formation of ordinary matter, such as hydrogen and helium atoms, as the universe expanded and cooled. This process emitted radiation that is significantly weaker — about a billion times fainter — than the well-known Cosmic Microwave Background (CMB) radiation.

CMB & CRR

Following the Big Bang, 13.8 billion years ago, the universe was extremely hot and dense, preventing electrons, protons, and nuclei from forming atoms. During this period, radiation was also released, which is now observed as the CMB.

CMB is essentially made of light, explained Mayuri. "It has been measured and matched to that of a black body — a theoretical entity that absorbs all frequencies of light and emits radiation based on its temperature. The black-body equivalent of CMB is about 3K or Kelvin (-270°C), which is extremely cold."

"The focus of the study is the spectrum of the CMB. The CMB spectrum does not match that of a perfect black body. CMB is distorted by processes with rich physics. CRR is one such distortion,” Mayuri explained.

Tech for precision

Keerthipriya Sathish, the lead author of the research, informed DH that the receiver for the antenna will be completed and the first results from the antenna can be expected in around five months.

The current sensitivity of the antenna is one part per 10,000. Using techniques adopted in this antenna design, the researchers plan to achieve the goal of one part per billion sensitivities.