Observations by the James Webb Space Telescope (JWST) have provided astronomers with unprecedented new insights into the early universe, thanks to detailed imagery of the quasar PJ308–21 recently obtained by NASA’s premier space observatory.
The new imagery reveals the appearance of this celestial object as it would have looked when the universe was less than a billion years old, offering a detailed view of the quasar’s spectrum and host galaxy.
Obtained with Webb’s NIRSpec instrument, the new imagery of quasar PJ308–21 reveals its spectrum with an uncertainty of less than 1% per pixel despite the object’s incredible distance. Data collected by Webb reveals that the quasar’s host galaxy and satellite galaxies show indications of dynamic processes that include photoionization.
One of the satellite galaxies showed low proportions of elements other than hydrogen or helium, which astronomers call metallicity, while another was revealed to possess higher metallicity and signs of partial photoionization from the nearby quasar.
Of key significance, the new discovery has enabled astronomers to predict the mass of the supermassive black hole at the center of the quasar system, which is now estimated to weigh in at close to 2 billion solar masses.
Quasar PJ308–21 and its surrounding galaxies are believed to be highly evolved and appear to be showing signs of steady growth in terms of mass and metal enrichment.
The discoveries are the latest in a series made possible by Webb, who provides information that helps astrophysicists expand their overall understanding of the history of our universe and how galaxies evolve.
Roberto Decarli, the lead author of a new study detailing the discoveries and a researcher at INAF in Bologna, says his team’s study “reveals that both the black holes at the center of high-redshift quasars and the galaxies that host them undergo extremely efficient and tumultuous growth already in the first billion years of cosmic history.”
The data Decarli and his team relied on was obtained two years ago as part of Program 1554, one of nine Italian-led projects comprising Webb’s first observation cycle, which Decarli leads.
Program 1554 was designed to specifically focus on observations of the merger between quasar PJ308–21’s galaxy and its satellite galaxies.
Federica Loiacono, an astrophysicist and research fellow at INAF, said that Webb’s NIRSpec instrument was crucial in allowing the team to study these vestiges of the early universe in the optical band for the first time and obtain diagnostic data about gas located near the black hole and in nearby galaxies.
“This allows us to compare hydrogen atom emissions with chemical elements produced by stars,” Loiacono said in a statement, adding that such observations allowed the team to “[determine] the metal richness of the gas in galaxies.”
Of key importance to the team’s research is Webb’s ability to collect information in the near and mid-infrared spectrum, facilitating the sensitivity required for high-precision observations. Yet despite Webb’s unprecedented capabilities, Decarli says the work still presented the team with some extraordinary challenges.
“The work represented a real ’emotional rollercoaster,’ requiring innovative solutions to overcome initial data reduction challenges,” Decarli said in a statement.
“The transformative impact of the James Webb Space Telescope’s instruments underscores its crucial role in advancing astrophysical research,” Decarli added. “Until recently, data on the enrichment of metals at these distances were almost beyond our reach.”
“Now we can map them in detail with just a few hours of observation, even in galaxies observed when the universe was in its infancy,” Decarli says.
Fundamentally, Decarli, Loiacono, and the team say their findings demonstrate the JWST’s unparalleled capabilities in exploring the distant universe, which offers astrophysicists a deeper understanding of the early stages of cosmic evolution than any previously attained.
The team’s recent study, “A quasar-galaxy merger at z~6.2: Rapid host growth via the accretion of two massive satellite galaxies,” was accepted for publication last month and will soon appear in the journal Astronomy and Astrophysics.
Micah Hanks is the Editor-in-Chief and Co-Founder of The Debrief. He can be reached by email at micah@thedebrief.org. Follow his work at micahhanks.com and on X: @MicahHanks.