Influence of jet measurements by heavy ion underlying event

The ATLAS program for heavy ion jet studies in the upcoming Pb Pb collisions will be outlined. With the collision energy provided by the LHC and the hermetic and highly segmented calorimeter, measurements of fully reconstructed jets in heavy ion collisions will be possible. Several differential studies that can be performed with fully reconstructed jets will be discussed, with the emphasis on the sensitivity of ATLAS jet measurements to the modification of the jet internal structure in heavy ion collisions. The similar measurements, of jet energy spectra and the jet internal structure, performed in p p collisions at 900 GeV with the ATLAS detector will also be presented.