Does Every Galaxy Have a Supermassive Black Hole or Are There Galaxies Without Black Holes?

The enigma of supermassive black holes (SMBHs) in galaxies has long intrigued scientists. It is often assumed that every galaxy at its center contains an SMBH, driving a never-ending cycle of accretion and emission. However, recent findings and theories challenge these assumptions.

The Toroidal Active Galactic Nucleus (AGN) Theory

Contrary to the widely held belief, some theories suggest that what we observe is not a black hole but a unique formation called a Toroidal Active Galactic Nucleus (AGN). An AGN consists of two opposing helical flows of accreted matter that heat up and re-ionize. These flows meet at the center, precessing in a way that powers opposing helical axial Quasar outflows primarily composed of plasma. This process is not akin to a black hole; rather, it behaves as an opposite of a black hole or a Schwarzschild White hole, according to some scientists.

Commonality and Exceptions

It is indeed a common occurrence for galaxies to harbor a supermassive black hole at their center. This is particularly true for elliptical, spiral, and peculiar galaxies, as well as larger galaxies in general. However, this is not a universal rule. Irregular galaxies often lack a central black hole due to their chaotic formation from galaxy collisions or collisions with other entities.

For instance, an irregular galaxy might indeed have numerous central bodies, or it may not have any at all. A notable example is where some galaxies have been found with three black holes, while others show no evidence of an SMBH at all. The existence of these black holes depends significantly on the galactic environment and formation history.

Galactic Accumulation and SMBH Formation

The formation of SMBHs is intricately linked to the galaxy's mass and size. Evidence suggests that larger galaxies are more likely to harbor more massive SMBHs, which accrue over time from the accumulation of matter. The accretion process forms an accretion disk around the black hole, eventually leading to the formation of a supermassive black hole. However, the rate and amount of matter available for accretion vary widely between galaxies.

Smaller galaxies may not have sufficient matter to form an SMBH, and some larger galaxies might lose their SMBHs due to various cosmic events. A prime example is the supergiant elliptical cD galaxy A2261-BCG, one of the largest known galaxies, which lacks an active supermassive black hole despite several studies indicating the possibility of a central black hole.

Implications and Further Research

The questions surrounding the presence of SMBHs in galaxies pose significant implications for our understanding of galactic evolution and structure. Continued research is essential to unravel the mysteries of these cosmic behemoths and their roles in the universe.

For more information on this topic, you can read the latest studies and reports.