The NOAO-XCS survey & the optical to X-ray scaling relations of galaxy clusters

Mehrtens, Nicola (2011) The NOAO-XCS survey & the optical to X-ray scaling relations of galaxy clusters. Doctoral thesis (DPhil), University of Sussex.

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In this thesis we present the NOAO-XMM Cluster Survey (NXS). NXS has provided optical follow-up of X-ray cluster candidates serendipitously detected by the XMM Cluster Survey (XCS). We report details on the execution, data reduction and analysis of 154 wide-field MOSAIC images containing 630 XCS cluster candidates.

We present a redshift algorithm, based on the ‘red-sequence technique’, designed to confirm cluster identifications and extract photometric cluster redshifts from NXS data.
This algorithm exploits the homogeneity of elliptical cluster galaxies to provide simultaneous redshift and optical richness estimates. In addition, we apply this redshift algorithm to the Sloan Digital Sky Survey public data releases SDSS DR7 and SDSS Stripe 82.

The resulting catalogue of ~500 optically confirmed XCS clusters with red-sequence redshifts is presented, spanning the redshift range 0.1<z<1.0. This sample will enable a
future XCS measurement of the cosmological parameters Ωm and σ8, as well as a selfconsistent measure of the cluster X-ray luminosity to temperature scaling relation.

Furthermore, for clusters with measured X-ray temperatures or luminosities, we measure the optical richness of red-sequence galaxies within the cluster virial radius (R200).
Using these measurements, we investigate the optical halo-mass scaling relation. Understanding cluster optical scaling relations, in particular the optical-light to halo-mass
relation, is key for surveys hoping to measure cosmological parameters using optically detected clusters alone. By combining the optical NXS and SDSS data sets with X-ray
information from XCS, this thesis provides much needed optical to X-ray scaling relations for future optical cluster surveys.

Item Type: Thesis (Doctoral)
Schools and Departments: School of Mathematical and Physical Sciences > Physics and Astronomy
Subjects: Q Science > QB Astronomy > QB0980 Cosmogony. Cosmology
Depositing User: Library Cataloguing
Date Deposited: 24 Jun 2011 09:15
Last Modified: 17 Aug 2015 13:16

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