Big Black Holes In Dwarf Galaxies
For the first time, NASA Chandra X-ray telescope has been used to discover a pair of black holes in dwarf galaxies that are on a collision course. The Chandra team explains.
Credit: NASA/CXC/A. Hobart
Credit: NASA/CXC/A. Hobart
Category
🤖
TechTranscript
00:00 Visit Chandra's beautiful universe.
00:04 Dwarf Galaxies
00:08 Astronomers have discovered the first evidence
00:12 for giant black holes in dwarf galaxies on a collision course.
00:16 This result from NASA's Chandra X-ray Observatory has important
00:20 ramifications for understanding how the first wave of black holes and galaxies
00:24 grew in the early universe. Collisions between the pairs
00:28 of dwarf galaxies have pulled gas toward the giant black holes they each contain,
00:32 causing the black holes to grow. Eventually,
00:36 the likely collision of the black holes will cause them to merge into much
00:40 larger black holes. The pairs of galaxies will also merge
00:44 into one. Scientists think the universe
00:48 was awash with small galaxies known as dwarf galaxies
00:52 several hundred million years after the Big Bang. Most merged
00:56 with others in the crowded, smaller volume of the early universe,
01:00 setting in motion the building of larger and larger galaxies now seen around
01:04 the local universe. Dwarf galaxies
01:08 by definition contain stars with a total mass less than about
01:12 3 billion times that of the Sun, compared to a total mass of
01:16 about 60 billion Suns estimated for the Milky Way.
01:20 The earliest dwarf galaxies are impossible to observe
01:24 with current technology, because they are extraordinarily faint at their large
01:28 distances. Astronomers have been able to observe two
01:32 in the process of merging at much closer distances to Earth,
01:36 but without signs of black holes in both galaxies.
01:40 Astronomers have found many examples of black holes on collision courses
01:44 in large galaxies that are relatively close by, but searches for
01:48 them in dwarf galaxies are much more challenging, and until now, had failed.
01:52 The new study overcame these challenges by implementing
01:56 a systematic survey of deep Chandra X-ray observations
02:00 and comparing them with infrared data from NASA's Wide Infrared Survey
02:04 Explorer, or WISE telescope, and optical data from the Canada-France
02:08 Hawaii telescope. Using this technique,
02:12 a group of researchers identified two pairs of merging dwarf galaxies
02:16 in separate galaxy clusters. The first
02:20 is Abell 133, which is located about 760
02:24 million light-years away. The second is the galaxy
02:28 cluster Abell 1758s, which is about 3.2
02:32 billion light-years from Earth.
02:36 Astronomers will use these systems as analogs for ones in the early universe,
02:40 so they can drill down into questions about the first galaxies,
02:44 their black holes, and star formation the collisions caused many
02:48 billions of years ago.
02:52 [music]
02:56 [music]
03:00 [music]