Quasars are among the universe’s brightest and most potent objects. A supernova’s Gamma Ray Burst may be more powerful, but it does not last long. Compared to the Milky Way, quasars are capable of emitting 1000 times more radiation for hundreds of millions of years.
All of this energy is derived from the supermassive black holes at the core of galaxies. As matter descends into a black hole, an accretion disk forms around it: a cloud of energetic material that heats up due to friction and emits electromagnetic radiation. From our perspective, the resulting Quasar can be so brilliant that it obscures the light from the rest of its galaxy.
Researchers announced on April 5 the discovery of an uncommon double quasar in the early universe. The two quasars are gravitationally bonded and are spiraling towards one another. Their host galaxies are currently merging, and the supermassive black holes that produce quasars will eventually collide and merge.
In a press release, Xin Liu, a researcher at the University of Illinois at Urbana-Champaign, stated, “We’re beginning to reveal the tip of the iceberg of the early binary quasar population.” This is the distinctive feature of this investigation. We now have a method to identify double quasars that are less than the size of a single galaxy apart.”
Detecting and analyzing signals from distant quasars is difficult, despite their brightness. This pair of quasars existed barely three billion years after the Big Bang, during a period known as cosmic noon: the period between 10 and 11 billion years ago when star formation in the Universe was at its pinnacle. They are extremely distant things.
It needed a broad team and a half-dozen telescopes to get this conclusion. The two objects are named after their Sloan Digital Sky Survey designations, J0749 + 2255, and were detected as a double quasar by the European Space Agency’s Gaia probe. Confirming the object’s characteristics required infrared images from both the Hubble Space Telescope and the W.M. Keck Observatory in Hawaii. Additional information about the objects was acquired using the International Gemini Observatory (optical and near-infrared), the Karl G. Jansky Very Large Array (radio), and NASA’s Chandra X-ray Observatory (X-ray).
Each wavelength provided different information about the quasars and helped researchers comprehend what was going on in this faraway binary galaxy system, much like putting together a puzzle.
Hubble’s high resolution also allowed them to rule out the notion that they were seeing the same quasar twice due to the wacky effects of gravitational lensing.
The double quasars J0749 + 2255 are so near together that they are separated by less than the space of a single galaxy, therefore resolving them at a distance of 10-11 billion light years away is an astonishing effort.
The future Nancy Grace Roman telescope from NASA will be suitable for discovering more double quasars. It will have a similar resolution to Hubble, but with a broader field of view to photograph more of the sky at once.
Astronomers will be able to create more accurate models of galaxy evolution in the early Universe with a greater sample size.