See my copyright notice for fair use practices.
High temperatures are on the left side and decrease to the right.
Low luminosities are on the bottom and increase vertically. Hubble constant slope of the line relating the speed of the galaxies away from each other and their distance apart from each other. The recession speed is derived from the redshift of the galaxy spectra and with the Hubble Law, it can be used to find the distance to the farthest galaxies. In normal stars and planet atmospheres, the outward-directed pressure is supplied by the thermal pressure of warm or hot gases.