Imagine a reservoir of water so large that it contains 140 trillion times more water than all of Earth's oceans combined. The stunning discovery was made by astronomers who have identified the largest and most distant reservoir of water ever detected in the universe. This gigantic aqueous mass surrounds a quasar located at a dizzying distance from our blue planet.
Matt Bradford, a researcher at NASA's Jet Propulsion Laboratory, highlights the importance of this discovery: “The environment around this quasar is unique, producing this colossal mass of water. This is further evidence that water is omnipresent in the universe, even in the most ancient times.” This statement puts into perspective our understanding of the distribution of water in the cosmos and its role in the evolution of the universe.
The quasar in question, named APM 08279+5255, is home to a supermassive black hole with a mass equivalent to 20 billion suns. This cosmic monster generates phenomenal energy, comparable to that of a thousand trillion suns. The presence of such a quantity of water around this quasar raises many questions about the mechanisms of formation and distribution of water in the early universe.
Water, a key witness to cosmic history
Water vapor plays a crucial role as a tracer gas, revealing valuable information about the nature of quasars and their environment. In the case of APM 08279+5255, this vapor extends over a gaseous region several hundred light years in diameter. This distribution indicates that the quasar bathes the surrounding gas with X-rays and infrared radiation, creating unique conditions in terms of temperature and density.
Although the gas temperature reaches a freezing cold -63°C, it remains five times higher and 10 to 100 times denser than in typical galactic environments. These exceptional conditions offer scientists a unique opportunity to study the physical processes at work in the early ages of the universe.
Analysis of water vapor and other molecules, such as carbon monoxide, suggests the presence of enough gas to fuel the black hole until it grows six times its size. However, the fate of this gas remains uncertain:
- It could condense to form new stars
- It could be thrown out of the quasar by the powerful forces at play
- It could contribute to the continued growth of the central black hole
An international scientific collaboration
The discovery of this colossal water reservoir is the result of an international collaboration involving several research teams. Initial observations began in 2008 with the use of “Z-Spec” at the California Institute of Technology's Submillimeter Observatory, located on Mauna Kea in Hawaii. Additional observations were conducted using the Combined Array for Research in Millimeter-Wave Astronomy (CARMA) in the Inyo Mountains in Southern California.
A second team, led by Dariusz Lis of Caltech, used the Plateau de Bure interferometer in the French Alps. In 2010, Lis' group accidentally detected the presence of water in APM 8279+5255. Bradford's team then shed light on the massive amount of water by detecting multiple spectral signatures.
This international collaboration highlights the importance of scientific cooperation in achieving major astronomical discoveries. Here is an overview of the main instruments used in this study:
| Instrument | Localisation | Role in discovery |
|---|---|---|
| Z-Spec | Cross Mountain, Hawaii | Initial observations |
| KARMA | Inyo Mountains, California | Additional comments |
| Bure Plateau Interferometer | French Alps | Incidental detection of water |
This remarkable discovery opens new perspectives on the presence and role of water in the primordial universe. It underlines the importance of continuing observations and research to unravel the mysteries of cosmic water and its impact on the evolution of the universe as we know it today.
https://arxiv.org/abs/1106.4301
