  The photon spectra measured by the ALICE collaboration in Pb+Pb collisions at
Large Hadron Collider (LHC) energies has been analyzed with a view of
extracting the properties of thermal system formed in these collisions. The
results of the analysis are compared with the previously studied spectra
measured at Super Proton Synchrotron (SPS) and Relativistic Heavy Ion Collider
(RHIC) energies. The thermal dilepton spectra from the Pb+Pb collision at LHC
energy has been predicted for the initial conditions constrained by the thermal
photon spectra at the same collision conditions. The slope of the photon has
been used to estimate the rise in the effective degeneracy with the charged
particle multiplicity of the system. The slopes of the lepton pair spectra for
different invariant mass windows have been used to conjecture the average
radial flow velocity of the high temperature phase.
