It is believed that black holes swallow so much surrounding material that they put an end to their host galaxy. In the process, they create a very energetic object called a quasar that was previously thought to stop starbursts. Now, scientists have found a galaxy that survives a quasi-ferocious force by continuing to give birth to new stars – about 100 sun-sized stars a year.
The discovery by the Stratospheric Observatory for Infrared Astronomy (SOFIA) may explain how massive galaxies came into being, even though the universe is dominated by galaxies that no longer form stars. The results are published in Astrophysical journal.
“This shows us that the growth of active black holes does not stop starvation immediately, which is contrary to all current scientific predictions,” said Allison Kirkpatrick, assistant professor at the University of Kansas at Lawrence Kansas and co-author of the study. . “It makes us rethink our theories about how galaxies evolve.”
SOFIA, a joint project of NASA and the German Aviation Center, DLR, studied an extremely distant galaxy located more than 5.25 billion light-years away called CQ4479. The core is a special type of quasar that was recently discovered by Kirkpatrick called a “cold quasar.” In this kind of quasar, the active black hole still celebrates material from its host galaxy, but the intense energy of the quasar has not ravaged all the cold gas, so stars can continue to form and the galaxy lives on. This is the first time scientists have a detailed look at a cold quasar that directly measures the growth of the black hole, star birth rate, and how much cold gas is left for fuel for the galaxy.
“We were surprised to see another oddball galaxy defying current theories,” said Kevin Cooke, a postdoctoral fellow at the University of Kansas at Lawrence, Kansas, and lead author of this study. “If this tandem growth continues, both the black hole and the stars around it would triple in size before the galaxy reaches the end of its life.”
As one of the brightest and most distant objects in the universe, quasars or “quasi-star radio sources” are notoriously difficult to observe because they often overshadow everything around them. They are formed when a particularly active black hole consumes huge amounts of material from its surrounding galaxy, creating strong gravitational forces. As more and more material spins faster and faster toward the center of the black hole, the material heats up and glows brightly. A quasar produces so much energy that it often overshadows everything around it and dazzles attempts to observe its host galaxy. Current theories predict that this energy heats up or expels the cold gas needed to create stars, stops starbursts, and drives a deadly blow to the growth of a galaxy. But SOFIA reveals that there is a relatively short period in which the galaxy’s star birth can continue, while the celebration of the black hole continues to drive the powerful forces of the quasar.
Instead of directly observing the newborn stars, SOFIA used its 9-foot telescope to detect the infrared light radiating from the dust heated by the star-forming process. Using data collected by SOFIA’s High-Resolution Airborne Wideband Camera-Plus or HAWC + instrument, scientists were able to estimate the amount of star formation over the last 100 million years.
“SOFIA lets us look into this short time window where the two processes can exist,” Cooke said. “It is the only telescope capable of studying star birth in this galaxy without being overwhelmed by the intensely luminous quasar.”
The short window of common black hole and stellar growth represents an early stage in the death of a galaxy, where the galaxy has not yet succumbed to the destructive effects of the quasar. Further research with SOFIA is needed to learn whether many other galaxies go through a similar phase of common black hole and stellar growth before eventually reaching the end of life. Future observations with the James Webb Space Telescope, scheduled for launch in 2021, will uncover how quasars affect the overall shape of their host galaxies.
Simulations show that the Webb Telescope can detect distant galaxies hidden in quasar glare
Kevin C. Cooke et al. Dying of the Light: An X-Ray Fading Cold Quasar at z ∼ 0.405, The Astrophysical Journal (2020). DOI: 10.3847 / 1538-4357 / abb94a
Provided by the Universities Space Research Association
Citation: Galaxy Survives Black Hole Party – For Now (2020, November 27) Retrieved November 27, 2020 from https://phys.org/news/2020-11-galaxy-survives-black-hole-feastfor.html
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