Photons and weak bosons do not interact strongly with the dense and hot medium formed in the nuclear collisions, thus should be sensitive to the nuclear modification of parton distribution functions (nPDFs). The in-medium modification of heavy quarkonium states plays an important role in studying the hot and dense medium formed in the larger collision systems. The ATLAS detector at the LHC, optimized for searching for new physics in proton-proton collisions, is especially well equipped to measure photons, Z, W bosons and quarkonia in the high occupancy environment produced in heavy-ion collisions. We present recent results on Z boson and charmonia yields as a functions of centrality, transverse momentum, and rapidity, from the ATLAS experiment.