On Sunday, 11 June 2017 21:46:50 UTC+2, Gerry Quinn wrote:

I would imagine that there has been a lot of work done in this area in
conjunction with studies of dark matter. Obviously the density and
distribution of baryonic dark matter (i.e. ordinary matter that's not in
stars) is a basic starting point for this research.

In fact, googling 'baryonic dark matter distribution' gives links which
will probably be in the ballpark of what you are interested in.


Baryonic dark matter? Is there something I'am missing?

When you go directly to the link:
https://en.wikipedia.org/wiki/Dark_m...s._nonbaryonic
Or https://en.wikipedia.org/wiki/Dark_matter and select paragraph 4
You will read:
"Dark matter can refer to any substance which interacts predominantly via
gravity with visible matter (e.g. stars and planets). Hence in principle
it need not be composed of a new type of fundamental particle but could,
at least IN PART, be made up of standard baryonic matter, such as protons
or electrons."

What is the current main stream opinion about "in part"?
IMO darkmatter is (was?) always considered as non-baryonic as compared to
normal matter which is considered as baryonic.

The problem is that the name dark matter is linked to the human sense: see.
visible versus invisible. And as such it is a very unlucky name.
A much better way is to make a distinction solely between baryonic and
non baryonic matter.

The problem is that in order to explain a galaxy rotation curve you can
assume a certain amount baryonic matter which density is so low that
it becomes invisible. The question is here what is this limit and how
much baryonic matter is involved.

Nicolaas Vroom.