Halton Arp was an American astronomer. He was known for his 1966 Atlas of Peculiar Galaxies, which (it was later theorized) catalogues many examples of interacting and merging galaxies, though Arp disputed the idea, claiming apparent associations were prime examples of ejections.[1] Arp was also known as a critic of the Big Bang theory and for advocating a non-standard cosmology incorporating intrinsic redshift.