float calcula_bg(float dec_, float ethres)
{

//gROOT->LoadMacro("radec2llbb.C");
//gROOT->LoadMacro("radec2spdetec.C");
//gSystem->Load("libcoordinate-service.so");
using namespace std;
//using namespace SLACoordinateTransform;

gROOT->LoadMacro("volkova.C");

//NeutrinoFlux nf("conv+prompt","bartol","naumov_rqpm","neutrinoflux/resources/data/");
//gROOT->LoadMacro("calcula_flujo.C");

//Step size:
//float stepsize=360; //one hour

//TFile *ff=new TFile("Aeffnu_astro_specaart.root");
TFile *ff=new TFile("Aeffnu_2d_aart.root");

 Float_t pre, cose;
 float inte_cos, energy, costheta;

int mjd=53300;
int sec=0;
int nsec=0;

int ninter=2400;

 float nor=1e-8;
 float spec=-2;

 //float ethres=1e1;

 int nbinsx=h2b->GetNbinsX();
 int nbinsy=h2b->GetNbinsY();

TH1F *hzen=new TH1F("hzen","",ninter,0,ninter);

TH1F *hcos=new TH1F("hcos","",nbinsy,0,1);

TH2F *hflux=new TH2F("hflux","",nbinsx,1,7,nbinsy,0,1);
TH2F *hflux2=new TH2F("hflux2","",nbinsx,1,7,nbinsy,0,1);
TH2F *hev=new TH2F("hev","",nbinsx,1,7,nbinsy,0,1);

//LocalToEqua lt;

//double ra_=30*TMath::DegToRad();
//double dec_=-15*TMath::DegToRad();
//ra_=ra_*TMath::DegToRad();
//dec_=dec_*TMath::DegToRad();

 double theta;
 double phi;
 double flux, flux1, flux2;
 float fondo;

for (int i=0;i<=(ninter-1);i++) {

  float dPhi = 2.*3.141 / ninter;
  float fac  = 3.141/180.;

  // float fLatDet=-90;
   float fLatDet=42.8;

  float zenith = acos(cos(dPhi*i)*cos(fLatDet*fac)*cos(dec_*fac) + sin(fLatDet*fac)*sin(dec_*fac));
  zenith = 180.-zenith/fac;

  //  float zenith2 = acos(cos(dPhi*i)*cos(fLatDet*fac)*cos((dec_+1)*fac) + sin(fLatDet*fac)*sin((dec_+1)*fac));
  //  zenith2 = 180.-zenith2/fac;
  //  float day=float(i)/24.;
  // lt.set_equatorial_coordinates(2000,ra_,dec_,53300+day);
  // lt.get_equatorial_coordinates(theta,phi);

  theta=zenith*TMath::DegToRad();
  float thetad=zenith;

  // cout << i << " " << thetad << endl;
   // theta=Equa2LocalZenith(ra_,dec_,date);
   // phi=Equa2LocalAzimuth(ra_,dec_,date);

 hzen->SetBinContent(i+1,thetad);

 hcos->Fill(cos(theta));

}

// inte_cos=hcos->Integral();
//if(inte_cos>0) hcos->Scale(1./ninter);
hcos->Scale(1./ninter);
 
 float ene1, ene2, cos1, cos2;
 for (int i=1; i<=nbinsx; i++) {
   for (int j=1; j<=nbinsy; j++) {
     
     ene1=pow(10,hflux->GetXaxis()->GetBinLowEdge(i));
     ene2=pow(10,hflux->GetXaxis()->GetBinLowEdge(i+1));
     //     cos1=hflux->GetYaxis()->GetBinLowEdge(j);
     //     cos2=hflux->GetYaxis()->GetBinLowEdge(j+1);

     energy=pow(10,hflux->GetXaxis()->GetBinCenter(i));
     costheta=hflux->GetYaxis()->GetBinCenter(j);

     // For using Bartol    
     //      flux1=3600*24*365*1e4*(nf.FluxAtmo(202,ene1,costheta)+nf.FluxAtmo(205,ene1,costheta));
     //      flux2=3600*24*365*1e4*(nf.FluxAtmo(202,ene2,costheta)+nf.FluxAtmo(205,ene2,costheta));

     // For using Volkova
     //flux1=3600*24*365*1e4*volkova(ene1,costheta);
     //flux2=3600*24*365*1e4*volkova(ene2,costheta);

     flux1=3600*24*365*1e4*nor*pow(ene1,spec);
     flux2=3600*24*365*1e4*nor*pow(ene2,spec);

     //Flux per year
     flux=(flux1+flux2)*(ene2-ene1)/2;
     //flux=3600*24*365*1e4*(nf.FluxAtmo(202,energy,costheta)+nf.FluxAtmo(205,energy,costheta))*(ene2-ene1);

     //     cout << "energy range:  " << ene1 << "  " << ene2 << endl;
     //     flux=3600*24*365*1e4*(nf.FluxAtmo(202,energy,costheta)+nf.FluxAtmo(205,energy,costheta));
     hflux->SetBinContent(i,j,flux);
     //     cout << "energy= " << energy << "   cos(theta)= " << cos(theta) << "   flux= " << flux << endl;
     
     
   }
 }
 
 
 //hcos->Draw();

 for (int i=1; i<=nbinsx; i++) {
   for (int j=1; j<=nbinsy; j++) {
     pre=hflux->GetBinContent(i,j);
     cose=hcos->GetBinContent(j);
     hflux2->SetBinContent(i,j,pre*cose);
     
   }
 }



 for (int i=1; i<=nbinsx; i++) {
   for (int j=1; j<=nbinsy; j++) {
     float con=hflux2->GetBinContent(i,j)*h2b->GetBinContent(i,j);
     hev->SetBinContent(i,j,con);
   }
 }


//   hev->Multiply(hflux2,h2b);
   hev->Draw("colz"); 

   float nbin1=(log10(ethres)-1)/6*nbinsx;
 fondo=hev->Integral(int(nbin1),nbinsx,1,nbinsy);
 
 return fondo;

}