NASA Focuses Space Telescope On Super Bright Quasars To Shed Light On The Early Universe

NASA's James Webb Space Telescope is still in the long and intricate process of aligning its mirrors, which needs to be completed before sending back pictures from deep space. Once JWST is fully operational, scientists are eager to begin studying quasars and their host galaxies, thereby potentially shedding light on the origin story of the universe.

Last week, the JWST team worked on the fourth stage of mirror alignment, called Coarse Phasing, which measures and corrects smaller height differences between mirror segments. The alignment process, which began last month, will take a total of three months to complete. Once everything is in place and the telescope reaches a suitable temperature, researchers will begin using the telescope to study quasars in hopes of unveiling the mysteries of the infant universe.

Quasars are extremely bright, distant, and active supermassive black holes. These black holes are millions to billions of times larger in mass of our very own Sun. The fact that a quasar is among the brightest objects in the universe, they outshine all the stars in its host galaxy combined.

Researchers will use the Webb telescope to gaze deep into the universe, and in doing so will be looking back into time. The light being emitted from these quasars began its journey billions of years ago. So, what JWST actually detects will be images from a distant past, not as they are today.

"All these quasars that we are studying existed very early, when the universe was less than 800 million years old, or less than 6 percent of its current age. So these observations give us the opportunity to study galaxy evolution and supermassive black hole formation and evolution at these very early times," explained Santiago Arribas, a research professor at the Department of Astrophysics of the Center for Astrology in Madrid, Spain.

The light these objects emit has been stretched by the expansion of space. This process is known as cosmological redshift. The farther light has to travel, the more it is redshifted. The fact that visible light being emitted from the early universe is stretched so dramatically that it is shifted out into the infrared by the time it reaches us, makes the suite of infrared-tuned instruments aboard Webb ideal for studying this kind of light.

"We're interested in observing the most luminous quasars because the very high amount of energy that they're generating down at their cores should lead to the largest impact on the host galaxy by the mechanisms such as quasar outflow and heating," states Chris Willott, a research scientist at the Hertzberg Astronomy and Astrophysics Research Centre of the National Council of Canada in Victoria, British Columbia. He continued, "We want to observe these quasars at the moment when they're having the largest impact on their host galaxies."

JWST will peer deep into space to gather more information about the period known as the Era of Reionization. This time period spanned over hundreds of millions of years, and is when the neutral gas in the intergalactic medium became charged or ionized, making it transparent to ultraviolet light. By understanding what led to the reionization that created the clear conditions detected in much of the universe today, scientists and researchers hope to understand one of the key frontiers in astrophysics.

"If you want to study the universe, you need very bright background sources. A quasar is their perfect object in the distant universe, because it's luminous enough that we can see it very well," said Camilla Pacifici, who is affiliated with the Canadian Space Agency. "We want to study the early universe because the universe evolves, and we want to know hot it got started."

Top Image Credit: NASA, ESA, Joseph Olmsted (STScl)