Large-scale image of the z = 1.709 cluster of galaxies SpARCS1049+56. Top left (a): composite HST image (F105W in blue and green; F160W in red) of the cluster. We highlight the location of the BCG and a foreground z ∼ 0.35 galaxy located to the southeast, labeled S3 in Figure 3 and discussed in Appendix B. Top right (b): XMM-Newton 0.5–2.0 keV X-ray image of the cluster. The image has been smoothed with a Gaussian filter of σ = 2 pixels. Overplotted are the Chandra X-ray contours at 2σ_rms, 3σ_rms, 4σ_rms, and 5σ_rms in green, which show the compact core of the cluster. The cyan contours show the diffuse extended LOFAR emission and are the same as the bottom-left plot. Bottom left (c): 144 MHz LOFAR 9″ image (Dutch stations only) with a beam size of 8﹩\mathop{.}\limits^{\unicode{x02033}}﹩9 × 4﹩\mathop{.}\limits^{\unicode{x02033}}﹩9. Contours are 2σ_rms, 3σ_rms, 4σ_rms, 5σ_rms, and 6σ_rms, where σ_rms = 35 μJy beam⁻¹. This image reveals a diffuse extended halo. Bottom right (d): 144 MHz LOFAR image, obtained with the International LOFAR Telescope, with a beam size of 0﹩\mathop{.}\limits^{\unicode{x02033}}﹩39 ×0﹩\mathop{.}\limits^{\unicode{x02033}}﹩22. The contours are the same as the bottom-left plot. Here, the only source detected is the AGN in the foreground z ∼ 0.35 galaxy, implying that the emission detected in the bottom left is of a diffuse nature. Color bars are included for radio images in units are Jy beam⁻¹.