At the center of the galaxy M77, some 47 million light-years from Earth, a supermassive black hole has finally been discovered hidden within a thick cloud of dust. Where the black hole hides in this dust cloud has been a mystery for decades, but scientists have now used detailed data from VLTI to measure the temperature at various points in the cloud to finally pinpoint the location of the supermassive black hole.
Active galactic nuclei (AGNs) are of various types, some emit radio waves and some don’t; some glow brightly in visible light, while others are softer, such as galaxy M77. Because there are so many subdivisions of appearance, astronomers introduced the AGN unified model, pointing out that although there are differences in active galactic nuclei, they all have the same basic structure: a supermassive black hole surrounded by a thick dust ring, all appearance differences in active galactic nuclei, It all depends on the different directions and angles from which we observe the black hole and the dust ring from the earth. If the dust ring is thick enough to block the black hole, the black hole can even be completely hidden under certain conditions.
Messier 77 (also known as M77, NGC 1068) is a barred spiral galaxy 47 million light-years from Earth and an active galaxy with an active galactic nucleus (AGN), but it is obscured by warm dust in the visible light band, and astronomical Questions remain about whether dust can completely hide a black hole, causing the AGN to be less bright than other AGNs in visible light.
Now thanks to the MATISSE instrument installed on the Very Large Telescope Interferometer (VLTI), the team of astronomer Gámez Rosas of Leiden University in the Netherlands has mapped the temperature change of the dust caused by the intense radiation of the black hole, not only finding the thick cosmic dust gas The ring also confirms the location of the supermassive black hole hidden in it, finally solving the problem of scientists for many years, and also providing important evidence to support the AGN unified model.
These findings may help determine the history of Sagittarius A*, the supermassive black hole at the center of the Milky Way, and analyze the interactions between active galactic nuclei and galaxies. The new paper was published in the journal Nature.