The typical image of a spiral galaxy has beautiful arms bending around its core, which bulges out with brightly lit gas surrounding a supermassive black hole. While many are confident every galaxy has a supermassive black hole at its heart, that characteristic bulge is missing from some spiral galaxies. Recent observations with the Chandra X-Ray Observatory of one of these bulge-less galaxies though may explain that.
The galaxy NGX 4178 is approximately 55 million light years away and appears to have a light-weight supermassive black hole that tips the scales at less than 200,000 solar masses. For comparison, the supermassive black hole at the center of the Milky Way is estimated to be in the millions of solar masses, which itself is dwarfed by the billion solar mass black holes found in some galaxies. This relatively low mass black hole may not be terribly unique though as researchers have found other galactic hearts that may also come in at about the same mass.
This discovery could have some interesting implications in cosmology, the branch of science that considers how galaxies and supermassive black holes form, amongst other things. The current theories would not allow for galaxies without bulges to contain supermassive black holes, which these galaxies demonstrate is not the case. This could indicate there is another method to creating supermassive black holes than currently theorized.