Christopher edited untitled.tex  about 9 years ago

Commit id: ac4515d32cbd0c2e7a6a84f52ad133e56617eff1

deletions | additions      

       

The major correction so far applied to this distant galaxy data concerns mergers. The local group data is based on galaxies that have not undergone mergers \textbf{is this true} and so to compare these data sets, the effects of mergers must be removed from this data set. To do this, the method described in \cite{Gomez_2015} has been used. Supporting material consisting of graphs showing expected merger rates at various mass ratios and redshifts has also been prepared.  The main analysis of the local group data was to do with the error bars reported by \cite{Weisz_2014}. These errors follow the conventions specified in \cite{Dolphin_2012} for systematic uncertainties and \cite{Dolphin_2013} for random. However, these uncertainties are extremely conservative and so instead we use the same convention as in \cite{Weisz_2014} which conservatively a relative uncertainty of 50%. 50\%.  We also apply a correction to both the local group and \cite{Whitaker_2014} data to account for mass loss. Both of these methods measure the total mass of stars formed in the galaxy and do not account for stellar death. Much of this death is a result of high mass, short lifespan stars and so we approximate this loss as instantanious with a multiplicative factor of 0.64. As the \cite{Tomczak_2014} data observes the mass of the galaxy rather than calculating it by star formation rates, this factor is not needed there.  Finally, a morphological correction is applied to the local group data. Approximately 50\% of the known galaxies in the local group appear in this data set. However, if we divide these galaxies into those attached to the milky way, those attached to M31 (Andromeda) and those in the field, we find that we do not sample from these groups evenly. This correction weights each galaxy to account for this sub sampling.