The two massive black hole couples were discovered by astronomers using
NASA's Chandra X-ray Observatory as they prepared for two unique
crashes.
Two distinct, previously unobserved collisions between two sets of massive
black holes, each in a different dwarf galaxy, are about to occur.
The four dwarf galaxy black holes were discovered by astronomers using
NASA's Chandra X-ray Observatory as they raced toward one another, leaving a
massive trail of debris and stars in their aftermath. The black holes are
already absorbing some of this material, which makes them enlarge even more
before collapsing.
The first pair was discovered in the Abell 133 galaxy cluster, 760 million
light-years away, and the second pair was discovered in the Abell 1758S
galaxy cluster, some 3.2 billion light-years away. Studying them as they get
closer to one another could help scientists better understand how the cosmic
monsters lurking throughout the universe grew to be so enormous. They are
expected to collide and combine to create even bigger galaxies. The results
were made public on Nov. 8 on the preprint repository
arXiv, and
The Astrophysical Journal has approved them for publishing.
In a statement, co-author Olivia Holmes, a physics student at the University of Alabama
in Tuscaloosa, said, "We've identified the first two different pairs of
black holes in colliding dwarf galaxies."(opens in new tab). We can delve
deeper into issues about the first galaxies, their black holes, and the star
creation that their collisions caused by using these systems as analogs for
ones in the early universe.
Black holes are created when massive stars collide, and they continue to
expand by devouring gas, dust, stars, and other black holes in the
star-forming galaxies that hold them. Scientists have long been baffled by
the issue of where the first black holes originated.
Billowing masses of cold gas may have combined into giant stars that were
destined to fall quickly and form black holes, according to previous models
of the "cosmic dawn"—the period covering the first billion years of the
universe. The ever-expanding trains of gas surrounding these black holes
collapsed into stars as they got bigger, ultimately creating dwarf
galaxies.
According to astronomers' theories, the first dwarf galaxy black holes
rapidly combined with other ones as the universe expanded to create even
larger supermassive black holes, which in turn seeded larger galaxies
throughout the heavens. However, no such collisions between black holes
within dwarf galaxies had previously been noticed.
The researchers surveyed Chandra X-ray images in order to look for these
illusive black hole mergers, then compared them to information obtained from
NASA's Wide Infrared Survey Explorer (WISE) and the Canada-France-Hawaii
Telescope at optical and infrared frequencies, respectively. (CFHT). Chandra
was used to hunt for pairs of galaxies sending out high-energy X-rays
because the gas orbiting black holes' maws can become extremely hot,
reaching temperatures of millions of degrees. They actually discovered not
just one, but two couples.
The first pair, in Abell 133, was already in the final stages of a merger,
according to the astronomers, and gravitational tidal effects have caused a
long tail of material to extend outward around the two black holes, which
they have dubbed "Mirabilis" in honor of an endangered species of
long-tailed hummingbird. The two black holes found in Abell 1758S, named
"Elstir" and "Vinteuil" after fictitious characters from Marcel Proust's "In
Search of Lost Time," are in the process of merging and are linked by a
massive bridge of stars and debris that has extended between them.
The analysis of the dwarf galaxies, according to the researchers, could
provide some crucial hints as to how the Milky Way's supermassive black hole
developed from a small black hole seedling to its current enormous
size.
According to co-author Brenna Wells, a physics student at the University of
Alabama in Tuscaloosa, "most of the dwarf galaxies and black holes in the
early universe are likely to have grown much larger by now, thanks to
repeated mergers," in the statement. Dwarf galaxies, which have developed
over billions of years to create large galaxies like our own Milky Way, can
be thought of as our galaxy's forebears.
