On Wednesday, March 1, 2017 at 1:43:29 PM UTC-8, Martin Brown wrote:
On 26/02/2017 04:43, ross wrote:
On Thursday, February 23, 2017 at 7:47:09 AM UTC-8, Martin Brown

If you instead add angular momentum that is orthogonal, then you
randomize the stellar orbits. This is what we see in ellipticals
and globulars.

Nonsense. If you added an orthogonal amount of angular momentum to=20
original galaxy one with W1 = (I, 0, 0) and add W2 = (0, I, 0)

You get a new merged galaxy with WTot = (I, I, 0)

In other words sqrt(2).I and at 45 degrees to the original spin axis.

Regards,
Martin Brown

OK, fine, yes I understand and see that result. But you are
considering just one infalling object and it's single interaction
with a single entity of the original galaxy.

Suppose I have a spiral galaxy, disk with central bulge. We can
find the net angular momentum.

Now, thought experiment, I take a bunch of mass, call it a bunch
of stars and I place them far above the spiral galaxy, say 100,000
to 200,000 light years from the black hole, in a clump along the
axis of rotation of the spiral galaxy. Then, I allow all of these
stars to rain down onto the spiral galaxy. They fall on random
sides of the black hole, and have random elliptical motions with a
very large eccentricity..........long axis parallel to the spiral
axis of rotation.

Suppose the total mass of this infalling material is significant
in comparison to, but smaller than, the mass of the spiral galaxy.

For each in falling thought experiment star, that interacts with a
star of the spiral, the net angular momentum will become as you
say, at a 45 degree angle. =20

HOWEVER, some of the in falling stars have a 45 degree angle one
way, and others have a 45 degree angle in another orientation. And,
as the falling stars manage to fall all around the black hole like
rain drops, the net angular momentum for each of these infalling
stars is in a different direction. Further, some are falling from
North pole down onto the galaxy, others are falling from the South
pole up into the galaxy, further increasing the random nature of
the resultant stellar motions.

Take those, and then secondary and tertiary further interactions
with the spiral galaxy stars, and the total motions become randomized
and the galactic net angular momentum will be reduced..........right?

Now I don't know that it is known what the faint extensions of
active galaxies are (gas, dust, stars, ????.........e.g. David
Malin's unsharp masking method for bringing out faint details for
these objects, showing extensions coincident with radio jet directions
for several active galaxies....

So I don't know that the extensions are stars (does anyone?)

But no matter what, if the total mass is significant and if that
mass rains back down, it still seems to me that it should reduce
the net angular momentum of the spiral.

rt