Photon yield as a function of charged particle multiplicity at midrapidity compared with Theoretical prediction by Shen (MB only) [1]. Photon spectrum is integrated over 1 < pt < 3 GeV/c, where thermal contribution is expected to contribute.     
Since photon yield is dominated by low pt point, NLOpQCD calculation by Vogelsang is omitted due to limited pt range (pt > 2 GeV/c). Due to issue of HM prompt photon Shen's HM calculation is now overlaid at HM.  
 

[1] PRC 95 (2017) 014906