Draw on histogram

I wanted to accomplish something but I am not sure how to go about it, my question is I want to draw something like

t1->Draw(“chirp[1] >> h_rec_mc”,wave_cuts_chirp_mass,"");

where h_rec_mc is the histogram. Problem is I dont know the range of chirp[1] so I dont know what to declare as dimension of h_rec_mc. The reason I want to draw on histogram is because I have already edited it for fonts and colors.

Please suggest a solution.

Hi,

I was able to get my thing done by using

FindFirstBinAbove