Even NASA’s Next-Generation Space Observatory can’t see supermassive black holes directly, but that doesn’t mean astronomers can’t use its data to better understand the mysterious behemoths.
The opportunities are even visible in the first science-grade images of the James Webb Space Telescope (nicknamed JWST or Webb) that NASA unveiled on July 12. Although supermassive black holes themselves are invisible to all observatories that collect light, JWST will be able to observe the structures indirectly.
He already has, in fact. Consider the new portrait of five galaxies that seem to be locked in a cosmic dance. “The photo we showed you of Stephan’s Quintet is beautiful, and it tells you so much in one image,” said John Mather of NASA’s Goddard Space Flight Center in Maryland, the telescope’s senior program scientist. James Webb, during a press conference organized on July 19 by the Committee for Space Research (COSPAR) as part of its annual meeting, which was held last week in Athens.
In this image, astronomers can see a supermassive black hole, or rather, light emitted by matter heating up and falling into the massive structure, which contains about 24 million times the mass of the sun, according the Space Telescope Science Institute in Baltimore, which operates the observatory. (The black hole is also called the active galactic nucleus for its position at the heart of galaxy NGC 7319.)
The stunning image released by NASA combines snapshots taken by both the Near Infrared Camera (NIRCam) and the Mid Infrared Instrument (MIRI). But JWST didn’t just capture photographs. The two instruments also collected what scientists call data cubes, which integrate both images and spectral analysisa technique that identifies the amount of light of a given wavelength coming from a source.
The results allowed scientists to separate the cloud surrounding the supermassive black hole, identifying how much of the chemicals of particular interest lay where. “We are testing the environment of a black hole,” Mather said of these observations. “We now have images of the shape of the hydrogen cloud, the iron cloud, the atomic hydrogen cloud, the molecular hydrogen, as they orbit or attempt to fall into the black hole’s gravitational field. “
And, as was the case with all of the sightings unveiled this month, Stephan’s Quintet observations came before the telescope had begun science operations in earnest; now JWST has embarked on what astronomers hope will be a 20-year tenure of groundbreaking science.
JWST’s predecessor, the The Hubble Space Telescopehas been operating for more than 30 years and continues to operate, and this older observatory has also contributed to scientists’ understanding of supermassive black holes.
“Hubble was the first to prove beyond doubt that we have a black hole at the center of galaxies, because they were able to observe the motion of stars in rapid orbits around a black hole,” Mather said.
Webb will go further, he noted. In particular, Mather said he hopes the JWST observations will teach astronomers about the origins of active galactic nuclei, the supermassive black holes that lurk in every galaxy‘score. “There is a giant black hole in the middle of every galaxy, and the origin of this black hole is completely unknown at present.”
As scientists attempt to solve this mystery, they will need to determine when supermassive black holes arrived on the cosmic scene. Unlike Hubble, which sees most clearly in the visible and ultraviolet wavelengths of light, the infrared-optimized JWST might be able to reach deep enough into the history of the universe to observe a time before such structures existed.
“It’s bigger so it can see further in time and further out in space, so we have more targets that we can find,” Mather said of the new observatory’s capabilities compared to Hubble’s. . “We’re also getting somewhat sharper images, and because infrared is able to penetrate dust clouds, we can see black holes much closer to the nucleus.”
And for Mather, understanding supermassive black holes is not a useless hobby. He noted that the supermassive black hole at the heart of a galaxy is a dominant player in the life of everything else in the galaxy, particularly because the energy released by the behemoth sculpts the galaxy around it. It’s no less true for us Milky Way than from the distant galaxy in Stephan’s Quintet.
“The history of the solar system would have been very different without the black hole in our galaxy,” Mather said.