This illustration represents the best evidence to date that the
direct collapse of a gas cloud produced supermassive
black holes in the early Universe. Researchers combined data from NASA’s
Chandra, Hubble, and Spitzer telescopes to make this discovery.
Credits: NASA/CXC/STScI
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Using data from NASA’s Great Observatories, astronomers have found
the best evidence yet for cosmic seeds in the early universe that should grow
into supermassive black holes.
Researchers combined data from NASA’s Chandra X-ray Observatory,
Hubble Space Telescope, and Spitzer Space Telescope to identify these possible
black hole seeds. They discuss their findings in a paper that will appear in an
upcoming issue of the Monthly Notices of the Royal Astronomical Society.
“Our discovery, if confirmed, explains how these monster black
holes were born,” said Fabio Pacucci of Scuola Normale Superiore (SNS) in Pisa,
Italy, who led the study. “We found evidence that supermassive black hole seeds
can form directly from the collapse of a giant gas cloud, skipping any
intermediate steps.”
Scientists believe a supermassive black hole lies in the center of
nearly all large galaxies, including our own Milky Way. They have found that
some of these supermassive black holes, which contain millions or even billions
of times the mass of the sun, formed less than a billion years after the start
of the universe in the Big Bang.
One theory suggests black hole seeds were built up by pulling in
gas from their surroundings and by mergers of smaller black holes, a process
that should take much longer than found for these quickly forming black holes.
These new findings suggest instead that some of the first black
holes formed directly when a cloud of gas collapsed, bypassing any other intermediate
phases, such as the formation and subsequent destruction of a massive star.
“There is a lot of controversy over which path these black holes
take,” said co-author Andrea Ferrara, also of SNS. “Our work suggests we are
narrowing in on an answer, where the black holes start big and grow at the
normal rate, rather than starting small and growing at a very fast rate.”
The researchers used computer models of black hole seeds combined
with a new method to select candidates for these objects from long-exposure
images from Chandra, Hubble, and Spitzer.
The team found two strong candidates for black hole seeds. Both of
these matched the theoretical profile in the infrared data, including being
very red objects, and also emit X-rays detected with Chandra. Estimates of
their distance suggest they may have been formed when the universe was less
than a billion years old
“Black hole seeds are extremely hard to find and confirming their
detection is very difficult,” said Andrea Grazian, a co-author from the
National Institute for Astrophysics in Italy. “However, we think our research
has uncovered the two best candidates to date.”
The team plans to obtain further observations in X-rays and the
infrared to check whether these objects have more of the properties expected
for black hole seeds. Upcoming observatories, such as NASA’s James Webb Space
Telescope and the European Extremely Large Telescope will aid in future studies
by detecting the light from more distant and smaller black holes. Scientists
currently are building the theoretical framework needed to interpret the
upcoming data, with the aim of finding the first black holes in the universe.
“As scientists, we cannot say at this point that our model is ‘the
one’,” said Pacucci. “What we really believe is that our model is able to
reproduce the observations without requiring unreasonable assumptions.”
NASA's Marshall Space Flight Center in Huntsville, Alabama,
manages the Chandra program while the Smithsonian Astrophysical Observatory in
Cambridge, Massachusetts, controls Chandra's science and flight operations.
The Hubble Space Telescope is a project of international
cooperation between NASA and the European Space Agency. NASA’s Goddard Space
Flight Center in Greenbelt, Maryland, manages the telescope. The Space Telescope
Science Institute (STScI) in Baltimore conducts Hubble science operations.
STScI is operated for NASA by the Association of Universities for Research in
Astronomy in Washington.
NASA's Jet Propulsion Laboratory in Pasadena, California, manages
the Spitzer Space Telescope mission, whose science operations are conducted at
the Spitzer Science Center. Spacecraft operations are based at Lockheed Martin
Space Systems Company, Littleton, Colorado.
For more on NASA’s Chandra X-ray Observatory, visit:
For more on NASA’s Hubble Space Telescope, visit:
For more on NASA’s Spitzer Space Telescope, visit: