We present joint X-ray and optical observations of the high-redshift (z similar or equal to 0.83) lensing cluster Cl J0152.7 - 1357 made with the Chandra X-Ray Observatory and the Keck telescope. We confirm the existence of significant substructure at both X-ray and optical wavelengths in the form of two distinct clumps, whose temperatures are 6.6(-1.5)(+2.4) and 5.7(-1.6)(+2.9) keV, respectively. The X-ray surface brightness profiles of the two clumps can be fitted by either a single beta-model or an NFW-like profile, the latter giving better fits to the central regions. We find that the X-ray - derived mass of this cluster is in good agreement with independent lensing measurements. While its appearance indicates that the cluster has not reached a dynamical equilibrium state, its X-ray luminosity L-X, temperature T, and dynamical mass M are consistent with the well-defined L-X-T and M-T relations for low-redshift galaxy clusters, which suggests that the dynamical properties of the clusters have remained almost unchanged since z approximate to 0.8.
Joint X-ray and optical measurements of the mass distribution of the distant galaxy cluster Cl J0152.7-1357
ROSATI, Piero
2004
Abstract
We present joint X-ray and optical observations of the high-redshift (z similar or equal to 0.83) lensing cluster Cl J0152.7 - 1357 made with the Chandra X-Ray Observatory and the Keck telescope. We confirm the existence of significant substructure at both X-ray and optical wavelengths in the form of two distinct clumps, whose temperatures are 6.6(-1.5)(+2.4) and 5.7(-1.6)(+2.9) keV, respectively. The X-ray surface brightness profiles of the two clumps can be fitted by either a single beta-model or an NFW-like profile, the latter giving better fits to the central regions. We find that the X-ray - derived mass of this cluster is in good agreement with independent lensing measurements. While its appearance indicates that the cluster has not reached a dynamical equilibrium state, its X-ray luminosity L-X, temperature T, and dynamical mass M are consistent with the well-defined L-X-T and M-T relations for low-redshift galaxy clusters, which suggests that the dynamical properties of the clusters have remained almost unchanged since z approximate to 0.8.I documenti in SFERA sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
