No one knows what an astrodimer is, dude.
ALL of them, except the Milky Way and the Andromeda galaxies.
The spectral lines from distant galaxies do not match those on Earth because of the Doppler effect, cosmic expansion, and differences in elements present in the galaxies. These factors cause the observed spectral lines to be shifted or altered compared to what we see on Earth.
See related questions.
You can see Earth, Mars, the Moon and galaxies!
They have broad emission lines of highly ionized elements.
No, Elements are the same everywhere in the Universe.
The vast distances involved means that the light we see left those galaxies a long time ago.
The vast distances involved means that the light we see left those galaxies a long time ago.
The closest ones near our galaxy.
Yes. See related question.
See related questions.
They are literally "uncountable"; every time we improve the telescope, we see more and more galaxies.