Electroweak bosons do not interact strongly with the dense and hot medium formed in nuclear collisions, and thus should be sensitive to the nuclear modification of parton distribution functions (nPDFs). The in-medium modification of heavy charmonium states plays an important role in studying the hot and dense medium. The ATLAS detector, optimized to search for new physics in proton-proton interactions, is well equipped to measure Z and W bosons as well as quarkonium in the high occupancy environment produced in heavy ion collisions. Results from the ATLAS experiment on W and Z boson yields as a function of centrality, transverse momentum and rapidity, in lead-lead and proton-lead collisions are presented. Quarkonium results from proton-lead interactions are also shown.