The Projected Dark and Baryonic Ellipsoidal Structure of 20 CLASH Galaxy Clusters
Abstract
We reconstruct the twodimensional (2D) matter distributions in 20 highmass galaxy clusters selected from the CLASH survey by using the new approach of performing a joint weak gravitational lensing analysis of 2D shear and azimuthally averaged magnification measurements. This combination allows for a complete analysis of the field, effectively breaking the masssheet degeneracy. In a Bayesian framework, we simultaneously constrain the mass profile and morphology of each individual cluster, assuming an elliptical NavarroFrenkWhite halo characterized by the mass, concentration, projected axis ratio, and position angle (PA) of the projected major axis. We find that spherical mass estimates of the clusters from azimuthally averaged weaklensing measurements in previous work are in excellent agreement with our results from a full 2D analysis. Combining all 20 clusters in our sample, we detect the elliptical shape of weaklensing halos at the 5σ significance level within a scale of 2 {Mpc} {h}^{1}. The median projected axis ratio is 0.67 ± 0.07 at a virial mass of {M}_{vir}}=(15.2+/ 2.8)× {10}^{14} {M}_{⊙ }, which is in agreement with theoretical predictions from recent numerical simulations of the standard collisionless cold dark matter model. We also study misalignment statistics of the brightest cluster galaxy, Xray, thermal SunyaevZel’dovich effect, and stronglensing morphologies with respect to the weaklensing signal. Among the three baryonic tracers studied here, we find that the Xray morphology is best aligned with the weaklensing mass distribution, with a median misalignment angle of  {{Δ }}{PA} =21^\circ +/ 7^\circ . We also conduct a stacked quadrupole shear analysis of the 20 clusters assuming that the Xray major axis is aligned with that of the projected mass distribution. This yields a consistent axis ratio of 0.67 ± 0.10, suggesting again a tight alignment between the intracluster gas and dark matter.
Based in part on data collected at the Subaru Telescope, which is operated by the National Astronomical Society of Japan.
 Publication:

The Astrophysical Journal
 Pub Date:
 June 2018
 DOI:
 10.3847/15384357/aac3d9
 arXiv:
 arXiv:1804.00664
 Bibcode:
 2018ApJ...860..104U
 Keywords:

 cosmology: observations;
 dark matter;
 galaxies: clusters: general;
 galaxies: clusters: intracluster medium;
 gravitational lensing: weak;
 Astrophysics  Cosmology and Nongalactic Astrophysics;
 Astrophysics  Astrophysics of Galaxies
 EPrint:
 Minor changes to match the version published in ApJ. One of three new companion papers of the CLUMP3D project (INon Chiu et al., arXiv:1804.00676