TY - JOUR

T1 - The XMM Cluster Survey analysis of the SDSS DR8 redMaPPer Catalogue

T2 - mplications for scatter, selection bias, and isotropy in cluster scaling relations

AU - Giles, P A

AU - Romer, A K

AU - Wilkinson, R

AU - Bermeo, A

AU - Turner, D J

AU - Hilton, M

AU - Upsdell, E W

AU - Rooney, P J

AU - Bhargava, S

AU - Ebrahimpour, L

AU - Farahi, A

AU - Mann, R G

AU - Manolopoulou, M

AU - Mayers, J

AU - Vergara, C

AU - Viana, P T P

AU - Collins, C A

AU - Hollowood, D

AU - Jeltema, T

AU - Miller, C J

AU - Nichol, R C

AU - Noorali, R

AU - Splettstoesser, M

AU - Stott, J P

PY - 2022/11/30

Y1 - 2022/11/30

N2 - In this paper, we present the X-ray analysis of SDSS DR8 redMaPPer (SDSSRM) clusters using data products from the XMM Cluster Survey (XCS). In total, 1189 SDSSRM clusters fall within the XMM-Newton footprint. This has yielded 456 confirmed detections accompanied by X-ray luminosity (LX) measurements. Of these clusters, 381 have an associated X-ray temperature measurement (TX). This represents one of the largest samples of coherently derived cluster TX values to date. Our analysis of the X-ray observable to richness scaling relations has demonstrated that scatter in the TX − λ relation is roughly a third of that in the LX − λ relation, and that the LX − λ scatter is intrinsic, i.e. will not be significantly reduced with larger sample sizes. Analysis of the scaling relation between LX and TX has shown that the fits are sensitive to the selection method of the sample, i.e. whether the sample is made up of clusters detected “serendipitously” compared to those deliberately targeted by XMM. These differences are also seen in the LX − λ relation and, to a lesser extent, in the TX − λ relation. Exclusion of the emission from the cluster core does not make a significant impact on the findings. A combination of selection biases is a likely, but yet unproven, reason for these differences. Finally, we have also used our data to probe recent claims of anisotropy in the LX − TX relation across the sky. We find no evidence of anistropy, but stress this may be masked in our analysis by the incomplete declination coverage of the SDSS.

AB - In this paper, we present the X-ray analysis of SDSS DR8 redMaPPer (SDSSRM) clusters using data products from the XMM Cluster Survey (XCS). In total, 1189 SDSSRM clusters fall within the XMM-Newton footprint. This has yielded 456 confirmed detections accompanied by X-ray luminosity (LX) measurements. Of these clusters, 381 have an associated X-ray temperature measurement (TX). This represents one of the largest samples of coherently derived cluster TX values to date. Our analysis of the X-ray observable to richness scaling relations has demonstrated that scatter in the TX − λ relation is roughly a third of that in the LX − λ relation, and that the LX − λ scatter is intrinsic, i.e. will not be significantly reduced with larger sample sizes. Analysis of the scaling relation between LX and TX has shown that the fits are sensitive to the selection method of the sample, i.e. whether the sample is made up of clusters detected “serendipitously” compared to those deliberately targeted by XMM. These differences are also seen in the LX − λ relation and, to a lesser extent, in the TX − λ relation. Exclusion of the emission from the cluster core does not make a significant impact on the findings. A combination of selection biases is a likely, but yet unproven, reason for these differences. Finally, we have also used our data to probe recent claims of anisotropy in the LX − TX relation across the sky. We find no evidence of anistropy, but stress this may be masked in our analysis by the incomplete declination coverage of the SDSS.

KW - Space and Planetary Science

KW - Astronomy and Astrophysics

U2 - 10.1093/mnras/stac2414

DO - 10.1093/mnras/stac2414

M3 - Journal article

VL - 516

SP - 3878

EP - 3899

JO - Monthly Notices of the Royal Astronomical Society

JF - Monthly Notices of the Royal Astronomical Society

SN - 0035-8711

IS - 3

ER -