Using Star Formation Rate to Measure Look- Back Time of Galaxy Clusters
Date Submitted
2017-04-12 14:44:56
GalEnv
Mikkel Lindholmer
University of Hull
Poster
Kevin A. Pimbblet (University of Hull)
In this work we use the property that on average star formation rate increases with redshift for objects with the same mass – the so called galaxy main sequence – to measure distance to galaxy clusters. We use the fact that a general galaxy population forms both a quenched and a star-forming sequence, and we locate these ridges in the SFR-M plane using a new method for galaxies taken from the Sloan Digital Sky Survey in discrete redshift bins. We fit the evolution of the galaxy main sequence with redshift using our method and then subsequently apply our method to a suite of X-ray selected galaxy clusters in an attempt to create a new distance measurement to clusters based on their galaxy main sequence. We demonstrate that although it is possible in a majority of galaxy clusters to measure the main sequences, the derived distance and look- back time derived from our galaxy main sequence fitting technique is only accurate to within 2.16 Gyr. We explore the reason between the differences in fitting the ridges in redshift bins and galaxy clusters and try to reduce the effect.