SZ/X-ray scaling relations using X-ray data and Planck Nominal maps

Abstract

We determine the relation between the Comptonization parameter predicted using X-ray data Y_{C, Xray} and the X-ray luminosity L_X, both magnitudes derived from ROSAT data, with the Comptonization parameter Y_{C, SZ} measured on Planck 2013 foreground cleaned Nominal maps. The 560 clusters of our sample includes clusters with masses M ≥ 10¹³ M_⊙, one order of magnitude smaller than those used by the Planck Collaboration in a similar analysis. It also contains eight times more clusters in the redshift interval z ≤ 0.3. The prediction of the β = 2/3 model convolved with the Planck antenna beam agrees with the anisotropies measured in foreground cleaned Planck Nominal maps within the X-ray emitting region, confirming the results of an earlier analysis. The universal pressure profile overestimates the signal by a 15-21 per cent depending on the angular aperture. We show that the discrepancy is not due to the presence of cool-core systems but it is an indication of a brake in the L_X - M relation towards low mass systems. We show that relation of the Comptonization parameter averaged over the region that emits 99 per cent of the X-ray flux and and the X-ray luminosity is consistent with the predictions of the self-similar model. We confirm previous findings that the scaling relations studied here do not evolve with redshift within the range probed by our catalogue.