void lowTime() {
  gROOT->SetStyle("Plain");

  TCanvas *c1=new TCanvas("c1","Canvas",800,600);
  gStyle->SetOptStat(0);
  gStyle->SetPalette(1);

  TFile::Open("Fe55Fit_S44_030mV.root");

  QT->SetTitle(";Peak signal (mV);Signal rise time (ns)");
  QT->GetXaxis()->SetRangeUser(60,159);
  QT->GetYaxis()->SetRangeUser(6,113);
  //PeakSignal->GetYaxis()->SetTitleOffset(1.2);
  QT->Draw("colz");

  c1->Update();
  c1->Print("../lowTime.png");
}