log10Mf

log10Mf is a quantity used in astronomy, specifically in the study of galaxy formation and evolution. It represents the base-10 logarithm of the stellar mass of a galaxy. Stellar mass is a fundamental property of a galaxy, indicating the total mass of stars it contains. Measuring stellar mass is crucial for understanding how galaxies form, grow, and evolve over cosmic time.

The quantity log10Mf is often used because stellar masses can span a very wide range, from small dwarf galaxies with masses of only a few million solar masses to massive elliptical galaxies containing trillions of solar masses. Taking the logarithm compresses this range, making it more manageable for statistical analysis and comparison. For example, a galaxy with a stellar mass of 10^9 solar masses would have a log10Mf of 9, while a galaxy with 10^11 solar masses would have a log10Mf of 11.

Astronomers typically derive stellar masses by analyzing a galaxy's spectral energy distribution (SED). This involves fitting observed photometric data (brightness in different wavelength bands) to theoretical models of stellar populations. The models take into account factors like the age, metallicity, and star formation history of the galaxy's stars. The resulting best-fit model provides an estimate of the total stellar mass.

The distribution of log10Mf values for galaxies in the universe, often referred to as the stellar mass function, provides important insights into the cosmic baryon fraction and the efficiency of star formation at different epochs. Studying how this distribution changes with redshift (lookback time) helps astronomers trace the assembly history of galaxies and understand the underlying physical processes driving galaxy evolution.