Star formation rate density as a function of galaxy mass at z < 0.2 with MUSE and GAMA surveys

The star formation rate density (SFRD) is an important tool in galaxy evolution that allows us to identify at which cosmic time galaxies are more efficient at forming stars. For low-mass star-forming galaxies, the SFRD as a function of stellar mass can be straightforwardly related to the galaxy stellar mass function (GSMF). Given the uncertainty of the GSMF at the low-mass end, due to the challenges in observing dwarf galaxies, deriving the SFRD with respect to mass may be crucial to understand galaxy formation. Measurement of SFRD is more complete than number density in a cosmological volume because galaxies with higher star formation rate (SRF) are easier to detect and characterize. In this work, the SFRD is derived using two different samples, one using the MUSE Wide and MUSE Hubble Ultra-Deep Field integral-field unit spectroscopic surveys, and another using the Galaxy and Mass Assembly spectroscopic survey. The first sample comprised a total of 27 star-forming galaxies at z < 0.2 (H alpha selected), whereas the second contained 7579 galaxies at z < 0.06 (r-band selected). The SRFs are derived from measurements of the H alpha emission line fluxes for the first sample, and using MagPhys SED fitting for the second one. The results show the behaviour of the SFRD to the lowest stellar masses of 10(5.5)M(circle dot), consistent with a constant slope (in log SFRD versus log stellar mass) and thus no turn-over in the GSMF.