Scientists have known for a long time that the core of most massive galaxies in the Universe beats the heart of the SMBH. The central regions of the galaxies are more energetic than the stars in their disks because of the presence of the giant black holes. AGN is an active nucleus. The Sagitarrius A* is a mass of over 4 million Suns and is found in the Milky Way.
Scientists have been studying these objects for decades in the hopes of learning more about their role in evolution. Current research shows that there may be more than one type of SMBH. A team of astronomer from the University of Texas at Austin found a black hole at the center of a dwarf galaxy that was close to the Milky Way. This finding could change our understanding of black holes.
Dr. Mara José Bustamante-Rosell, a physicist at UT Austin, was the leader of the research team. The Astrophysical Journal has a study that describes their findings.
The path of the star S2 is very close to the black hole at the center of the Milky Way. Credit: M. Kornmesser
The researchers decided to study the dwarf galaxies because they don't seem to have much dark matter. The density of dark matter changes from the outer edges of the galaxy into its center, which is what the dark matter profile describes. Calculating density is done by measuring how fast the stars are moving, with faster speeds indicating that more matter is in the stars.
The team wanted to know if dark matter density increases towards the center. They wanted to know if their profile measurement would match their previous data. They used data from the McDonald Observatory's 2.7-meter (8.85-foot) Harlan J. Smith Telescope.
The team fed their results and models into the Texas Advanced Computing Center and received some amazing results. The results implied that the center of the universe has more mass than the disk, and that the black hole in the center is as big as Sagittarius A*. UT Astronomy Prof. Karl Gebhardt explained in a recent news release.
The models are telling you that you don't need a lot of dark matter, and that you need a black hole at the center. The black hole in the small galaxy that is falling into the Milky Way is about the same size as the one in the Milky Way. The mass ratio is very large. The black hole is almost the same as the Milky Way.
The Fornax Dwarf galaxy is one of the earliest dwarf spheroidal galaxies. Credit:DSS2
The results of previous observations of Leo I have changed due to a combination of better data and simulations. The central region of the dwarf galaxy was not explored by previous studies because they were only interested in the velocities of individual stars. There was a bias in previous studies that decreased the amount of matter enclosed within their orbits.
The central region is unaffected by this bias and therefore the data in this present study has increased estimates considerably. The finding could have a huge impact on astronomy, as well as how SMBHs form and grow over time. Said Gebhardt.
If the mass of the black hole is high, that could explain how black holes grow. As small galaxies like Leo I fall into larger ones, the black hole in the smaller one becomes larger, increasing its mass.
The result is significant because it shows how dark matter is distributed within the galaxies. The existence of a new type of black hole will give the observatory a new signal to look for.
The VIRUS-W is the only instrument in the world capable of conducting this type of dark matter profile study. Next- generation telescopes will have comparable spectrographs in the coming years, thanks to UT Austin and the Giant Magellan Telescope. Along with space telescopes, these observatories will show new light on the "Dark Universe."
The Astrophysical Journal has further reading.
