Mpch

Mpch, short for "megaparsecs per hour," is a unit of measurement used in astronomy to describe the rate of expansion of the universe. It is derived from the Hubble constant, which quantifies the rate at which galaxies are moving away from each other due to the expansion of the universe. The Hubble constant is typically expressed in units of kilometers per second per megaparsec (km/s/Mpc), but for larger scales and timescales, it is sometimes converted to megaparsecs per hour (Mpc/h). This conversion is useful for comparing the expansion rate over cosmological timescales. The value of the Hubble constant in Mpc/h is approximately 70, which means the universe is expanding at a rate of 70 megaparsecs per hour. This unit is particularly relevant in cosmological studies and models, such as the Lambda-CDM model, which describes the evolution of the universe from the Big Bang to the present day.