Current and future optical surveys for cosmology
Measuring eBOSS Completeness using Clustering Redshifts
Dominic Bates
Rita Tojeiro
University of St Andrews
Spectroscopically confirmed redshifts are extremely useful in both cosmology and galaxy evolution, as they allow populations to be studied at different cosmological times. When spectra are not available, redshifts are often estimated through photometric data, however this can be inaccurate, and can sometimes lead to catastrophic redshift failures, particularly when objects are faint or distant. An alternative technique to this, which does not does not depend on galaxy photometry, but only angular positions, is known as clustering redshifts, where redshift distributions of galaxy populations are obtained directly from their clustering with respect to a large spectroscopic sample of galaxies.

In this project, data from spectroscopic redshift surveys (SDSS, BOSS, eBOSS) are used, to implement a method of obtaining clustering redshifts for any population of galaxies. This can then be applied to large numbers of photometric galaxies with different photometric properties, which will be initially used to estimate the completeness of eBOSS (i.e. the number of galaxies eBOSS is missing at different masses / magnitudes / colours). This implementation should have many further applications, since redshift distributions of any arbitrary population of galaxies can be obtained through this method.


09:00 - 10:30
EX - LT1 (100)