The Most Interesting Galaxies in the Universe
By (author) Joel L Schiff
Publication date:
12 September 2018Publisher
Morgan & Claypool PublishersISBN-13: 9781643270029
Prior to the 1920s it was generally thought, with a few exceptions,
that our galaxy, the Milky Way, was the entire universe. Based on the
work of Henrietta Leavitt with Cepheid variables, astronomer Edwin
Hubble was able to determine that the Andromeda Galaxy and others had to
lie outside our own. Moreover, based on the work of Vesto Slipher,
involving the redshifts of these galaxies, Hubble was able to determine
that the universe was not static, as had been previously thought, but
expanding.
The number of galaxies has also been
expanding, with estimates varying from 100 billion to 2 trillion. While
every galaxy in the universe is interesting just by its very fact of
being, the author has selected 60 of those that possess some unusual
qualities that make them of particular interest. These galaxies have
complex evolutionary histories, with some having supermassive black
holes at their core, others are powerful radio sources, a very few are
relatively nearby and even visible to the naked eye, whereas the light
from one recent discovery has been travelling for the past 13.4 billion
years, and from a time when the universe was in its infancy. And despite
the vastness of the universe, some galaxies are colliding with others,
embraced in a graceful gravitational dance. Indeed, as the Andromeda
Galaxy is heading towards us, a similar fate awaits our Milky Way.
When
looking at a modern image of a galaxy, one is in awe at the shear
wondrous nature of such a magnificent creation, with its boundless
secrets that it is keeping from us, its endless possibilities for
harboring alien civilizations, and we remain left with the ultimate
knowledge that we are connected to its glory.