Double astronomical milestone: the largest collection of dwarf galaxies and black holes is unveiled
A team of more than 900 researchers suggests that these elements are relics of the early Universe
BarcelonaUp to 300 intermediate-mass black holes and 2,500 active black holes in dwarf galaxies. This is the double discovery of an international team of scientists through the Dark Energy Spectroscopic Instrument (DESI), which could expand human understanding of the Universe and pave the way for future research into galaxy formation.
Published this Wednesday in the journal The Astrophysical Journal, is the largest collection to date of dwarf galaxies and black holes. The research involved the collaboration of more than 900 researchers from universities and research centres in seventy countries, including the Institute for Space Studies of Catalonia (IEEC).
The scientists used DESI, located at the Kitt Peak National Observatory in the United States, a state-of-the-art instrument – built and operated with US government funding – that can capture light from 5,000 galaxies simultaneously. The first data from the instrument have yielded an unprecedented set of spectral data from 410,000 galaxies, including 115,000 dwarf galaxies, which are small, diffuse galaxies with thousands to millions of stars and very little gas.
In addition, more than 300 candidates for intermediate-mass black holes have been identified. Most are either light (less than 100 times the mass of the Sun) or supermassive (more than a million times the mass of the Sun), but those in between are poorly understood. Researchers suspect that they are the relics of the first black holes to form in the Universe and the "seeds" of the supermassive black holes at the centers of today's large galaxies.
Science Challenge
Astrophysicists are fairly certain that all massive galaxies, like the Milky Way, have black holes at their centers, but that finding them is challenging, especially in dwarf galaxies because of their size and the capabilities of current instruments.
The team identified 2,500 dwarf galaxies that are candidates for hosting an active galactic nucleus (AGN), suggesting that a substantial number of low-magnitude black holes have been overlooked.
