Baryonic fraction, in clusters of galaxies.

It's about mass of clusters of galaxies.

And groups and clusters of galaxies occupy region outside.

We now turn our attention to clusters of galaxies.

So let's recap what we learned about clusters of galaxies.

And that's how we can estimate mass of clusters of galaxies.

Dark matter potential wells are still collapsing, forming the first cores of galaxies, and clusters of galaxies.

Now continuing our study of clusters of galaxies, let's consider their content.

Of all galaxies, maybe 10 or 20 are found in clusters.

And typical modern catalogs of clusters of galaxies using sky survey plates would have 10s of 1,000s of clusters in.

So clusters of galaxies will tend to form, because of all this gravitational attraction.

lensing. This has been done on galaxies as well as clusters.

So that is not as hot as x ray gas in clusters of galaxies.

Now, if we plug in typical numbers, say, for extent of dark halos of galaxies and sizes of clusters of galaxies, we find out that the relative collapse times are a few hundred million years for galaxies and few billion years for clusters.

What can be done is to measure the local matter density of the universe, using dynamics of galaxies or clusters of galaxies near us.

Here's one of those clusters that seems to have resulted from a merger as two clusters of galaxies and what the picture here shows.

And then we needed some way to turn those fluctuations into galaxies and clusters of galaxies and make these kinds of structures go on.

At the time of the recombination, the Jeans Mass drops precipitously by many orders of magnitude, roughly from super clusters of galaxies to scale of globular clusters.

Well relaxed looking, symmetric round clusters tend to be dominated by elliptical galaxies.

Ruggedy, flat ish looking clusters are those where they're dominated by spiral galaxies.

Instead of the x ray gas, you can use other test particles in case of elliptical galaxies, those could be globular clusters or dwarf galaxies around them.

There is one important distinction though, the early type galaxies, ellipticals and S0s tend to concentrate in clusters more than in general field and there is relatively few spiral galaxies in clusters.

A very small angular separations, which will largely be for galaxies that really are physically close together like in clusters or galaxies.

Right now this is super cluster of galaxies scale and as we get closer in, you're going to see details that are more like current clusters of galaxies.

Now let's turn to galaxies and clusters. One thing that will happen is a galaxy

Shapley Concentration of clusters.

As it turns out, it actually runs into problems with observations with clusters of galaxies or even actually globular star clusters and its proponents keep tweaking it up.

One is based on so called Sunyaev Zeldovich effect, which measures Distances to clusters of galaxies using observations of cosmic microbackground.

Just a not about those central dominant galaxies and clusters, or cD as they are called.

The most gas deficient spirals are found in near a cores of clusters of galaxies, where as those on the outskirts look like pretty much like spiral galaxies in the field.

The idea is that smaller structures will form through fragmentation, of the larger ones, like galaxies forming after the clusters.

And clusters of banana plants.

Groups of galaxies are indeed where most of the galaxies are.

A more detailed analysis which also includes mass and galaxies then yields to the typical Baryonic fraction clusters of the order of fifteen .

Open clusters

Globular clusters

Star Clusters

Open Clusters

Globular Clusters

You can do very similar thing for elliptical galaxies which is essentially same thing we've done for clusters.

So, once we reach the scales of clusters of galaxies or beyond, the mix of visible and non baryonic dark matter seems to be constant.

Where some scales of clusters of galaxies and large scale structure formation would be on scales of billions of years, and that scale responds to observations.

This kind of study is, is now done not just for big clusters of galaxies, but just in general deep field surveys, where we measure a lot of faint galaxies, and sometimes get measurements of their redshifts.

Galaxies

Most of the astrophysical objects in galaxies or clusters are vastly larger than their Schwarzschild radii, so the effect isn't quite as strong.