Astronomers have created the largest map of the volume of the universe to date using a new map of active supermassive black holes at the centers of galaxies. A bright black hole, also known as a quasar, is ironically one of the brightest objects in the universe. A new map records the spatiotemporal locations of about 1.3 million quasars, the most distant of which shone brightly when the universe was just 1.5 billion years old, 13.7 billion years old. . “This quasar catalog differs from all previous catalogs in that it provides his three-dimensional map of the largest volume of the universe to date,” said the map’s co-creator, Flatiron Institute. said David Hogg, senior researcher at the centre. Computational astrophysicist in New York City and professor of physics and data science at New York University. “This is not the catalog with the most quasars or the highest quality quasar measurements, but it is the catalog with the largest total volume of the universe mapped.” Hogg and his colleagues published this map in a new paper published in the Astrophysical Journal. The paper’s lead author, Kate Storey-Fisher, is a postdoctoral researcher at the International Physics Center Donostia in Spain.
Scientists created the new map using data from the European Space Agency’s Gaia space telescope. Although Gaia’s main purpose is to map the stars in our galaxy, it can sometimes accidentally discover objects outside the Milky Way, such as quasars and other galaxies, while scanning the sky. “We were able to measure how matter clumped together in the early universe as precisely as measurements from large international research projects.” It is quite surprising considering that the data received was received from a focused Gaia project. said Story Fisher, who led part of the research as a graduate student at New York University. A quasar is powered by a supermassive black hole at the center of a galaxy that has hundreds of thousands to billions of times the mass of the Sun and is hundreds of times brighter than the entire galaxy. When a black hole’s gravity stirs up nearby gas, the process creates a very bright disk and, in some cases, a beam of light that can be observed with telescopes. Galaxies containing quasars are surrounded by a huge halo of invisible matter called dark matter. By studying quasars, astronomers can learn more about dark matter, including how strongly it clumps together. Astronomers can also use the locations of distant quasars and their host galaxies to better understand how the universe has expanded over time. For example, scientists are already comparing the new quasar map with the universe’s oldest light, the so-called cosmic microwave background radiation, to study how powerful the accumulation of matter is in the universe.
“It was very exciting to see how this catalog led to so many new scientific discoveries,” says Story-Fisher. “Researchers around the world use quasar maps to measure everything from the initial density fluctuations that formed the cosmic web, to the distribution of voids in the universe, to the movement of our solar system through space.” The research team used his third release of data from Gaia, which includes 6.6 million quasar candidates or potential quasars, along with data from NASA’s Wide-Field Infrared Survey Explorer and Sloan Digital Sky Survey . By combining the datasets, the team was able to remove contaminants such as stars and galaxies from Gaia’s original contaminant dataset and more accurately determine the distances to quasars. The research team also created a map of where dust, stars, and other clutter can obstruct the view of some quasars. This is important in interpreting quasar maps. “This catalog of quasars is a great example of how productive astronomy projects can be,” Hogg says. “Gaia was designed to measure stars in our galaxy, but it also discovered millions of quasars, giving us a map of the entire universe.”
source: https://iopscience.iop.org/article/10.3847/1538-4357/ad1328