200 most important Astronomy topics - Sykalo Eugen 2023

The Hydrogen Epoch of Reionization Array (HERA)

The Hydrogen Epoch of Reionization Array (HERA) is a cutting-edge radio telescope that is currently under development to study the early universe. It is designed to detect the faint signals from the cosmic dawn, a time when the first stars and galaxies were formed. The HERA project is being led by a consortium of universities and research institutions based in the United States, South Africa, and the United Kingdom. Once completed, HERA will be the largest radio telescope in the world dedicated to studying the early universe.

What is the Hydrogen Epoch of Reionization?

The Hydrogen Epoch of Reionization (EoR) is a period in the history of the universe that occurred around 380,000 years after the Big Bang. During this time, the universe was filled with neutral hydrogen gas that absorbed radiation from the cosmic microwave background, a remnant of the Big Bang. As the universe expanded and cooled, the hydrogen gas began to clump together, eventually forming the first stars and galaxies. These early sources of radiation reionized the hydrogen gas, making it transparent to light again.

The EoR is an important period in the history of the universe because it marks the transition from the "dark ages" to the "cosmic dawn." It was during this time that the first galaxies formed, and the universe began to look the way it does today. Studying the EoR can provide insights into the formation and evolution of the early universe, as well as the properties of dark matter and dark energy, two mysterious substances that make up most of the universe.

How does HERA work?

HERA is a radio telescope that is designed to detect the faint signals from the EoR. It consists of a large array of antennas that are sensitive to radio waves at a frequency of 100-200 MHz. These antennas are arranged in a grid pattern and are connected to a central computer that processes the data.

HERA is designed to detect the faint signals from the EoR by looking for changes in the brightness of the sky. As the universe began to reionize, the hydrogen gas became transparent to light again, allowing the light from the first stars and galaxies to travel freely through space. This caused a change in the brightness of the sky that HERA is designed to detect.

To achieve its scientific goals, HERA needs to have a very low level of radio frequency interference (RFI). This is because RFI can interfere with the faint signals from the EoR that HERA is designed to detect. To minimize RFI, the HERA team has chosen a remote site in South Africa where the level of RFI is very low.

Why is HERA important?

HERA is important because it will allow astronomers to study the EoR in greater detail than ever before. By studying the EoR, astronomers hope to learn more about the formation of the first stars and galaxies, and the evolution of the universe as a whole.

One of the main scientific goals of HERA is to measure the power spectrum of the EoR. The power spectrum is a mathematical tool that describes the distribution of signal power as a function of spatial frequency. By measuring the power spectrum of the EoR, astronomers can learn about the properties of the hydrogen gas during this epoch, such as its temperature and density.

HERA will also help astronomers to understand the nature of dark matter and dark energy, two mysterious substances that make up most of the universe. By studying the EoR, astronomers hope to learn more about how these substances influence the evolution of the universe.

In addition to its scientific goals, HERA is also important because it is a major international collaboration that is bringing together scientists and engineers from around the world. The HERA team is made up of experts in radio astronomy, cosmology, engineering, and computer science, among other fields. By working together, they are pushing the limits of what is possible in radio astronomy and advancing our understanding of the early universe.