Located in the constellation of Grus, the four main galaxies in this region of the sky are of the spiral type. At the bottom right we have NGC7552. The smallest of the three in the upper left corner is NGC7590, with its companion next to NGC7599. The most central and the most studied of these is NGC7582. NGC7582 is a type 2 Seyfert galaxy, such classification is due to the fact that the galaxy has an extremely bright central supermassive black hole very similar to a quasar, the most energetic objects in the universe. The black hole in the center of NGC7582 is about 10 million times the mass of our sun.
These closely spaced galaxies are the subject of intense studies to understand their interactions with each other. The strong star activity of two of the members, namely NGC 7552 and NGC 7582, is believed to result from the galaxy-galaxy "tidal" interaction and the subsequent formation of a bar in the disk. You can also see a map of the Hydrogen layers (Ha) of three of the members. We see, among other things, NGC7582 at the bottom center and a tidal tail to its right which points in the direction of NGC7552.
Ha Map Link
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