Question

How density of ordinary matter varies throughout the Universe? How the density of "dark matter" varies through the Universe? How the density of "dark energy" varies throughout the Universe?

Answer 1

The universe is mainly composed of the large scale structures like galaxies, galaxy cluster and super clusters and galaxy filament and the intergalactic mediums. The galaxies are composed of luminous matter which includes main sequence stars, giant and supergiant stars and supernovas, dark matter which found in galactic bulge, center of the galaxy and galactic halos, includes supermassive black hole, stellar mass black holes, different stellar remnants like brown dwarf, neutron star, white dwarf etc.

The intergalactic medium contains a lot of gas and dust particles, H II regions, supernova remnants, planetary nebulae, reflection and dark nebulae, cosmic rays, H I regions and galactic magnetic field.

There are some sort of interaction and interchange happens between these components. During the formation of stars, the interstellar medium provide the basic ingredients and these materials comes back with enriched metal content when the stars die.

Similarly the stellar remnants contribute to the formation of black hole and neutron stars which increase the dark matter Content.

Since the interaction of dark energy with baryonic matter is not properly understood yet, it's interconversion is complicated.

The density of ordinary matter varies in different parts of the galaxy. In the spiral arms of spiral galaxy, parts of irregular galaxy and galactic bulges the density is much high rather than the interstellar medium. Within the ISM, the density varies from 1 particles in cubic cm to 1 million particles in cubic cm.

The density of dark matter is more in galactic halo and Corona where as it is negligible in the remaining parts of the galaxy.

Since the dark energy is related with the expansion of space time, we consider it's density is constant throughout the universe.