Galactic Tectonics and a Galactic Life Cycle
S. R. Holland --
1998, revised May 2011
Stars have a well-accepted life cycle, where young stars age to produce heavier elements, then die in various ways, usually blasting elements into space to form new stars. I make the controversial assumption that galaxies also have a parallel life cycle. Young galaxies form from spiralling jets out of active galaxies. They age and become larger with accretion of gas, globular clusters, and mergers with other galaxies.

This article suggests giant ellipticals may be in the range of 100 billion years old, and the Galactic Life Cycle involves a Steady State universe. This obviously clashes with the Big Bang hypothesis. I propose that astronomical observation trumps physics theory. Can anyone claim he knows all the phenomena and laws of physics at the Intergalactic scale so well that he can guarantee there is no other explanation of the Red Shift except the Doppler Effect? ---- (page under construction, more coming soon).

Active galaxies often produce jets. I propose these jets can sometimes produce young spiral galaxies
when rotating lumps drag the linear jets into spiral arms.
Many Arp Irregular Galaxies may be showing us these birth stages.
All bulges or "bars" are oblong because they were originally lumps of extra matter in a linear jet.

One arm of the young spirals may often be traceable to the parent active galaxy. These primary arms are the original linear jet. Continued rotation eventually drags the jet-arms toward a circular shape

Zw II 98 -- I propose this is a beautiful example of the actual birth of a spiral galaxy on the left from a self-destructing active galaxy. The spiral shape can appear very quickly if the intrinsic twisting of the jet is appropriate, or if it encouters resistance from the Intergalactic Medium. An irregular cloud seems to forming on the right, as if some of the jet action is bipolar. M51 appears very similar to Zw II 98 in developmental stage, but M51 is seen more broadside. See also the Chandra image.
A single long jet produced in a short time would produce lumps of the same age, leading to spiral arms with lumps that appear similar in age (amount of gas and star compositions) throughout most of the length of the arms, as show in M51..
Eventually the original spiral arms wrap tighter into circular arms.

The Milky Way is assumetd to be in the range of ~10+ billion years old. We can use this as a very rough baseline time for such things as a generally circular look, partially diffuse arms, number of globular clusters, and ratio of bulge to disk diameter.
As the oblong bulge rotates, it sets up density waves in the disk which form secondary arms, blurring the disk.

Is M31 substantially older than our galaxy as shown by the diffuse disk and 3x the globular clusters
or it may just be in a denser environment with more raw material.

NGC 1300
Accretion of material and smaller galaxies over tens of billions of years
is the dominant pattern here, expanding the bulge and thickening the disk,
creating lenticular galaxies, and eventually giant ellipticals.

Giant Ellipticals look like a giant bulge because that is what they are -- swollen with accreted stars with random orbits.

I suggest M87, with 10x the globular clusters of M31, and having accreted much mass,
could be ~100 billion years old or more.


This is a very speculative estimate


Under construction -- more coming (23 May 2011)