![]() ![]() Scientists used computer models to understand how double quasars form, and where they form naturally in the universe. Nianyi Chen (left) and Tiziana Di Matteo (right), Department of Physics, Carnegie Mellon University. In a way it’s like reconstructing a 3D movie from a single picture." From a simulation we have access to much richer temporal and spatial information. And that picture is blurred by instrumentation and matter. "In this case we just see the double quasar at one point in its life and from one angle. “Observations give us only a single snapshot in time," said Nianyi Chen, a doctoral student working with Di Matteo in Carnegie Mellon’s Department of Physics. ![]() As the simulation runs, researchers can witness possible scenarios about how the universe and given objects within the universe have evolved over time. For the simulations, her team seeds a computer program with conditions about the early universe. Key to furthering this research is cosmological simulations. “If we observe more double quasars, we can begin to put limits on theories about early black hole growth and galaxy assembly,” Di Matteo said. While astronomers believe that galaxies and black holes merged frequently during this time, they have only observed a few double quasars. The quasar pair observed by Hubble comes from a time period known as “cosmic noon,” which is believed to be the peak of star formation and black hole growth. Credit: Carnegie Mellon University/Nianyi Chen. This set of images follows the evolution of the pair for a hundred million years, until the supermassive black holes merge in the last panel. The background shows the host galaxies of the quasars, and the colored lines and crosses follow the trajectories of the supermassive black holes powering the quasars. Observing early quasars, and in particular pairs of them, helps us understand how cosmic structures first form in our universe and the basic processes by which black holes grow.”Ī visualization of a double quasar evolution from the Carnegie Mellon simulation closely matches the system observed by the Hubble Space Telescope. “Quasars are small in size but play a fundamental role in how galaxies form and evolve into their present state. “Understanding how black holes form, the first quasars emerge, and how they grow along our cosmic histories is one of the greatest theoretical and observational challenges of modern astrophysics,” said Tiziana Di Matteo, professor of physics and director of Carnegie Department of Physics. Double quasars have rarely been observed but are thought to be a tell-tale sign of a galaxy merger. Researchers just recently have been able to see quasars in the early universe due to the power of the current generation of telescopes like Hubble. As black holes feed, they emit energy that heats up and illuminates the dust and gas that they consume. Quasars are among the brightest objects in the universe and are created by invisible supermassive black holes, which live at the center of large galaxies. An international group of researchers, including cosmologists from Carnegie Mellon University reported the discovery in the April 5 issue of Nature. ![]() NASA’s Hubble Space Telescope made an unexpected discovery - a pair of gravitationally bound quasars inside of two merging galaxies that existed when the universe was just three billion years old. Image credit: NASA, ESA, Joseph Olmsted (STScI).Īdapted from a press release by Jocelyn Duffy, Carnegie Mellon University. The gravitational tug-of-war between the two galaxies ignites a firestorm of star birth. This artist's concept shows the brilliant glare of two quasars residing in the cores of two galaxies that are in the chaotic process of merging.
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