Why dwarf galaxies near Milky Way, are found in the thin layer near the Milky Way?

The Milky Way is one of the spiral galaxies.  

Finnish astronomers found the answer to that problem. The location of those dwarf galaxies is a coincidence. That form where most of those dwarf galaxies are on certain layers is a coincidence. And someday in the future, the motion of those dwarf galaxies will break that form. But the fact is that the location of those dwarf galaxies is not (probably) fully coincidental. When our galaxy rotates around the supermassive black hole called Sagittarius A.

A centripetal force will throw material like gas and dust out from the milky way. That means that dust and gas will slow the motion of those dwarf galaxies. So dust and gas that is leaving the Milky Way will slow those dwarf galaxies and traps them in that position. 

There could be multiple positions where those dwarf galaxies are slowing. So that explains why those dwarf galaxies are in thin layers. But in this text, I just use the edge of the main spiral structure as an example. 

In that area, gas and dust that are leaving the Milky Way are impacting with gas and dust that is coming from other galaxies. That impact causes whirls. And there at the equator of the Milky Way is also forming more dwarf galaxies than anywhere else. 

The milky way rotates around a supermassive black hole called Sagittarius A. That rotational movement makes the spiral structure of the giant spiral galaxy act like a rotating layer. That means the centripetal force will push gas and dust out from the galaxy from its elliptic's equator. 

So that gas and dust will trap those small galaxies in the equatorial layer of the Milky Way. Gas and dust that escape from Milky Way are not very dense. But that thing causes friction when the dwarf galaxies are traveling across that structure. So those dwarf galaxies are spending more time in that area than in other places around the milky way. 

https://www.avaruus.fi/uutiset/tahdet-sumut-ja-galaksit/suomalaiset-tahtitieteilijat-ratkaisivat-galaktisen-arvoituksen.html

https://www.nature.com/articles/s41550-022-01856-z