Nebulae or star clusters within the Milky Way Galaxy.
The redshift of distant galaxies is believed to be a result of the Doppler effect - in other words, the light is shifted towards lower frequencies ("redshifted") due to the fact that the galaxies move away from us.
Elliptical galaxies are large blob shaped galaxies that most galaxies will eventually look like. Elliptical galaxies are what happens when two or more large galaxies collide and coalesce.
Over time - billions of years - galaxies will merge with other galaxies. In about 3 billion years, the Andromeda galaxy will merge with our own galaxy, the Milky Way.However, the separation between galaxies is so great, that not all galaxies will merge unless the fundamental issue of the amount of mass in the Universe is determined.If we live in a "contracting universe" then eventually all galaxies will merge.
The answer to this is we do not know but it looks unlikely.The expansion of the universe appears to be speeding up. Local Galaxies might merge into larger galaxies but these galaxies will expand faster and faster away from each other.
Among other things, that they were static in space
Irregular galaxies are believed to have been spiral or elliptical galaxies in the past, which have been distored through gravitational pull of neighboring galaxies.
Galaxies do combine or merge together. In about 4.5 -> 5.5 billion years time time, the Andromeda Galaxy will combine with our galaxy, the Milky Way Galaxy. In a lot of cases Irregular Galaxies are believed to have formed with interactions with other galaxies. See related link for a picture of two galaxies merging.
Not all galaxies, but it is believed that the majority of galaxies have central black holes.
The redshift of distant galaxies is believed to be a result of the Doppler effect - in other words, the light is shifted towards lower frequencies ("redshifted") due to the fact that the galaxies move away from us.
Edwin Powell Hubble
Perhaps you mean "thought to be"? - It is believed that all, or most, galaxies have a supermassive black hole at their center.
These small galaxies are believed to be the result of collisions between larger spiral galaxies. During such collisions pieces of the spiral arms get flung out into space, becoming small irregular galaxies.
There are several hundred billion galaxies in the KNOWN (or observable) Universe; the actual Universe, however, is believed to be much, much bigger.
Yes it is believed that the Milky Way is getting bigger. A galaxy can only grow if it swallows mass from outside it. Galaxies merge and are absorbed by other galaxies in a process known as Galactic Cannibalism. It is currently believed that a dwarf Galaxy known as the Sagittarius Dwarf is being slowly swallowed by the Milky Way.
Because of their age, elliptical galaxies are believed to have older stars and less gas and dust in their insterstellar medium than other types of galaxies, and thus their nebulae are less common. However, nebulae are presumed to exist in almost all galaxies; and some recent observations hint that the central black holes of elliptical galaxies may tend to preserve interstellar gas by preventing it from cooling enough for star formation.
It's generally believed that galaxies first formed around "ordinary" black holes and over time, they grew into super massive black holes as stars were slowly "consumed" by the black hole.
there is only 1 universe and their is billions of galaxies in it !