ESA/Gaia/DPAC; SDSS (inset)
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McDonald Observatory astronomers have discovered that Leo I (insertion), a small satellite galaxy of the Milky Way (main image), has a black hole nearly as large as the Milky Way.
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Nationalgeographic.co.id—Astronomers from the University of Texas at Austin’s McDonald Observatory have discovered black hole A very large one is at the heart of one of the Milky Way’s dwarf satellite galaxies, called Leo I. Black hole it’s almost as big as black hole in our own galaxy.
The finding could redefine our understanding of how all galaxies evolve. The results of this study have been published in the latest issue The Astrophysical Journal on 05 November 2021 entitled Dynamical Analysis of the Dark Matter and Central Black Hole Mass in the Dwarf Spheroidal Leo I.
The research team decided to study Leo I because of its uniqueness. Unlike most of the dwarf galaxies orbiting the Milky Way, Leo I does not contain much dark matter. The researchers measured Leo I’s dark matter profile, which is how the density of dark matter changes from the galaxy’s outer edges to its center. They do this by measuring their gravitational pull on the stars: The faster the stars move, the more matter they contain in their orbits.
Specifically, the team wanted to find out if the density of dark matter increased towards the galactic center. They also wanted to find out if their profile measurements would match those previously made using older telescope data combined with computer models.
Led by recent UT Austin doctoral graduate María José Bustamante, the team including UT astronomers Eva Noyola, Karl Gebhardt and Greg Zeimann, as well as colleagues from Germany’s Max Planck Institute for Space Physics (MPE), carried out the observations using the instrument. called VIRUS-W on the McDonald Observatory’s 2.7-meter Harlan J. Smith Telescope.
When the team fed their state-of-the-art data and models into a supercomputer at UT Austin’s Texas Advanced Computing Center, they got surprising and unprecedented results.
“The models scream that you need a black hole in the center; you don’t really need a lot of dark matter. You have a very small galaxy falling into the Milky Way, and the black hole is almost as big as the Milky Way. The mass ratio is huge. The Milky Way is dominant; a Leo I black hole is almost comparable.” said Gebhardt.
The researchers say the results differ from previous Leo I studies due to a combination of better data and supercomputer simulations. The dense central region of the galaxy has been largely unexplored in previous studies, which concentrated on the speed of individual stars. The current study shows that for some speeds taken in the past, there is a bias towards low speeds. This, in turn, reduces the amount of inferred matter enclosed in its orbit.
ESA / ATG medialab
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The illustration shows a black hole inside a dwarf galaxy.
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The new data are concentrated in the middle region and are not affected by this bias. The amount of matter inferred to be enclosed in the orbits of the stars skyrocketed.
The finding could shake astronomers’ understanding of galaxy evolution, because “there is no explanation for black holes of this kind in dwarf spheroidal galaxies,” Bustamante said.
“The results are even more important because astronomers have been using galaxies like Leo I, called ‘dwarf spheroidal galaxies’, for 20 years to understand how dark matter is distributed within galaxies. This merging of new types of black holes also gives observatories gravitational waves a new signal to search for.” said Gebhardt.
ESO / M. Grain knives
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The star’s strange behavior has also revealed the existence of other black holes lurking beyond our galaxy.
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Also Read: Black Hole Found Hidden in a Star Cluster Outside the Milky Way
“If the masses black hole Leo I is tall, that might explain how black hole it grows in massive galaxies. That’s because over time, as small galaxies like Leo I fall into larger galaxies, black hole smaller galaxies merge with larger galaxies, increasing their mass.” explained Gebhardt, as reported Tech Explorist.
Built by the team at MPE in Germany, VIRUS-W is the only instrument in the world today that can perform profile studies of this type of dark matter. Lots dwarf galaxies The southern hemisphere is a good target for that, but no southern hemisphere telescope is equipped for that. However, the Giant Magellan Telescope (GMT) currently under construction in Chile has, in part, been designed for this type of work. UT Austin is a founding partner of GMT.
Hopefully in the future, this research will get better results with the help of this telescope.
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