A team led by researchers at the University of Michigan used NASA’s Chandra X-ray Observatory to study more than 1,600 galaxies observed over more than 20 years. The sample included very large galaxies and many dwarf galaxies. The work appeared in The Astrophysical Journal.
The study found about 30% of dwarf galaxies likely contain supermassive black holes, while more than 90% of massive galaxies like the Milky Way show signs of central black holes. Smaller galaxies usually did not show clear X-ray signals. Researchers say small black holes are fainter, but also many small galaxies may simply lack central black holes. Future tests could come from the Laser Interferometer Space Antenna planned for 2035.
Difficult words
- galaxy — A large system of stars and gas.galaxies
- dwarf — A much smaller type of galaxy.
- supermassive — Extremely large and heavy, especially for black holes.
- researcher — A person who studies a subject scientifically.researchers
- central — At or near the middle of something.
- signal — A sign or message detected by instruments.signals
Tip: hover, focus or tap highlighted words in the article to see quick definitions while you read or listen.
Discussion questions
- What do you think about the result that about 30% of dwarf galaxies have supermassive black holes?
- Why is it hard to see black holes in small galaxies?
- Would you like to work with telescopes or space observatories? Why or why not?
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