The detection of gravitational waves has opened up a new era of astronomical exploration, and the proposed Einstein Telescope promises to take us even further into the past, revealing the secrets of the universe’s earliest black hole mergers.
Probing the Cosmic Dawn
Today, the universe is far different from its early days when the first stars and galaxies sprang to life. These original stars, referred to as Population III, were incredibly massive and had only short lives. And contained almost zero heavy elements from which they could generate a core-collapse supernova explosion.
Their properties and evolutionary history are essential clues to decipher the long, intricate story of cosmic evolution that winds its way from the Cosmic Dark Ages to the universe we see around us today. Theoretical astrophysicists think that the black hole seeds forming from the first stars may have provided the stepping stones to building some of the earliest largest supermassive black holes, which ultimately boosted their respective galaxies.
Through modeling the formation and merger of these early black hole binaries, researchers now estimate that the planned Einstein Telescope could detect up to 1400 such mergers every year, creating a new benchmark for understanding the Cosmic Dawn and structure formation in its infancy.
Like most of mankind, I am very proud we did it. — at Earth
The detection of gravitational waves in 2016 was a turning point in astronomy; this method has provided new prospects for studying the universe. Since then, more than 100 events involving gravitational waves have been detected – yielding information on everything from the interiors of supernovae and neutron stars to the expansion rate of the universe and conditions within a minute after the Big Bang.
At the moment, though, gravitational wave detectors like LIGO and VIRGO are designed to observe binary black holes relatively nearby, as sources of gravitational waves. For astronomers to study the early universe in more detail, they will require next-generation observatories such as the planned Einstein Telescope.
The more advanced facility will, in fact, be sensitive enough to detect gravitational waves from all early black hole mergers even the earliest that took place when the first stars were still being formed. This will allow us to understand how these early structures form and evolve through the analysis of the properties and merger rates of primordial black hole binaries.
Conclusion
Since then, following the first direct detection of gravitational waves, it was clear that this initial event had opened a new window to the astronomy world coming from very distant past times, or detailed about some black hole mergers happening in the early Universe. The study is aimed at understanding how the cosmos has evolved from the Cosmic Dark Ages to the present-day universe by observing these ancient black hole binaries. Understanding what it is that we see could teach us new things about the first stars and galaxies, or maybe even how supermassive black holes came to be — phenomena that have drastically shaped the cosmos over time.
