Astronomers have recently unveiled the largest map of active supermassive black holes in the universe, which are located in the centers of galaxies. These objects, known as quasars, are known for absorbing gas and being one of the brightest objects in the universe. The new map pinpoints the locations of roughly 1.3 million quasars, with some of the most distant ones dating back to when the universe was just 1.5 billion years old, compared to its current age of 13.7 billion years.
David Hogg, a co-author of the map and a senior researcher at the Flatiron Computing Astrophysics Center in New York, describes this quasar map as unique because it is a three-dimensional representation of the largest volume of the universe so far. While it may not be a catalog featuring the biggest or most precisely measured quasars, it covers a vast portion of the universe.
The map was crafted using data collected from the European Space Agency’s Gaia space telescope, which primarily focuses on mapping stars within our galaxy. Despite this mission, Gaia has also captured data on objects outside the Milky Way, including quasars and other galaxies.
Researchers utilized the third release of Gaia data, which included 6.6 million potential quasars, along with data from NASA’s infrared all-sky survey and the Sloan Digital Sky Survey. By combining these datasets, the team was able to filter out contaminants like stars and galaxies from the initial Gaia data and more accurately determine the distances to quasars.
Quasars, which derive energy from supermassive black holes in galaxy centers, can shine hundreds of times brighter than the entire galaxy itself. Studying quasars allows astronomers to gain insights into dark matter and its accumulation throughout the universe.
The quasar catalog has already piqued the interest of scientists worldwide, who are using it to explore a wide range of cosmic phenomena, from the early density fluctuations that shaped the cosmic web to the distribution of galaxies and the trajectory of our solar system within the universe.
This map serves as a testament to the success of astronomical projects. While Gaia was originally designed to chart the stars in our galaxy, it has also led to the discovery of millions of quasars, resulting in a comprehensive map of the entire universe.