Redshift measurement through star formation

E. A. Milne Centre for Astrophysics, University of Hull, Cottingham Rd, Hull HU6 7RX, UK
e-mail: M.Lindholmer@2016.hull.ac.uk

Received: 19 March 2018
Accepted: 15 December 2018

Abstract

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 the redshift of galaxy clusters. We use the fact that the general galaxy population forms both a quenched and a star-forming sequence, and we locate these ridges in the SFR–M_⋆ plane with galaxies taken from the Sloan Digital Sky Survey in discrete redshift bins. We fitted the evolution of the galaxy main sequence with redshift using a new 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 several galaxy clusters to measure the main sequences, the derived distance and redshift from our galaxy main sequence fitting technique has an accuracy of σ_z = ±0.017 ⋅ (z + 1) and is only accurate up to z ≈ 0.2.