Weak lensing analysis of A115, A2219 and A2261: Detection of galaxy groups and filaments around clusters

We present a weak lensing and multi-wavelength analysis of three galaxy clusters: A115, A2219, and A2261. Weak lensing is performed using shape measurements made in short 60s exposure images obtained using WIYN-ODI. Forced measurement is used to measure low Signal to Noise (SNR) sources in individual exposures. We find the weak lensing significance map recovers the galaxy clusters and most galaxy groups in the wide 40$'$ $\times$ 40$'$ field. Significant parts of the filamentary structures over this field, as indicated by the galaxy number density map, were also successfully recovered in lensing significance maps. We find the amount of structure recovery depends on both the depth and average seeing of the images. In particular, we detect a $>$ 9 Mpc long structure that contains the cluster A2219. We compare our weak lensing maps with Chandra, XMM, and LOFAR observations and find that A115 and A2219 show clear signs of ongoing mergers. In particular, we find a significant separation of hot ICM and the weak lensing contours in A115. On the other hand, while A2261 appears relaxed, based on radio and X-ray analysis, we find that it is likely interacting with a structure 700 kpc SW of the main cluster. We also successfully recovered mass structures in two regions around A2261 indicated by diffuse X-ray emission in XMM images.