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
|
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:
http://www.nasa.gov/chandra