The large broadband noise up to some hundred Hz is highly coherent between Hrec and V1:DET_B1_DC, as a result of a dedicated BruCo run: link (I'm currently rerunning the script to fix the cropped y-scale). In the table, you can find also a bunch of channels coherent with the large peak at 43 Hz.

Figure 1: coherence and noise projection of V1:DET_B1_DC to Hrec.