double estimate_merging_time(int halonr, int mother_halonr, int p)
{
int central_halonr;
double coulomb, mergtime, SatelliteMass, SatelliteRadius, MotherHaloRvir;
/** @brief Binney & Tremaine 1987 - 7.26 merging time for satellites due to
* dynamical friction. After Delucia2007 *2, shown to agree with
* Kolchin2008 simulations in Delucia2010. This is set when a galaxy
* becomes a type 2 or being a type 1 \f$M_{\rm{star}}>M_{\rm{vir}}\f$.
* In DeLucia2007 they could only merge into a type 0, now (after
* guo2010) they can merge into a type 1. */
/* recipe updated for more accurate merging time (see BT eq 7.26),
now satellite radius at previous timestep is included */
central_halonr = Halo[Halo[halonr].Descendant].FirstProgenitor;
if(Gal[p].Type == 1)
central_halonr=mother_halonr;
if(central_halonr == halonr)
{
terminate("can't be...!\n");
}
coulomb = log(Halo[mother_halonr].Len / ((double) Halo[halonr].Len) + 1);
/* should include stellar+cold gas in SatelliteMass! */
SatelliteMass = get_virial_mass(halonr)+(Gal[p].DiskMass+Gal[p].BulgeMass);
SatelliteRadius = separation_halo(central_halonr,halonr)/(1 + ZZ[Halo[halonr].SnapNum]);
int j;
for (j = 0; j < 3; j++)
Gal[p].DistanceToCentralGal[j] = wrap(Halo[central_halonr].Pos[j] - Halo[halonr].Pos[j], BoxSize);
MotherHaloRvir = get_virial_radius(mother_halonr);
if(SatelliteRadius > MotherHaloRvir)
SatelliteRadius = MotherHaloRvir;
if(SatelliteMass > 0.0) {
mergtime = 1.17 * SatelliteRadius * SatelliteRadius * get_virial_velocity(mother_halonr) /
(coulomb * G * SatelliteMass); // Binney & Tremaine Eq.7.26
/* change introduced by Delucia2007 to fit observations */
mergtime = 2.*mergtime;
}
else
mergtime = -99999.9;
return mergtime;
}
void prepare_galaxy_for_output(int filenr, int tree, struct GALAXY *g, struct GALAXY_OUTPUT *o)
{
int j, step;
o->SnapNum = g->SnapNum;
o->Type = g->Type;
// assume that because there are so many files, the trees per file will be less than 100000
// required for limits of long long
if(LastFile>=10000)
{
assert( g->GalaxyNr < TREE_MUL_FAC ); // breaking tree size assumption
assert(tree < (FILENR_MUL_FAC/10)/TREE_MUL_FAC);
o->GalaxyIndex = g->GalaxyNr + TREE_MUL_FAC * tree + (FILENR_MUL_FAC/10) * filenr;
assert( (o->GalaxyIndex - g->GalaxyNr - TREE_MUL_FAC*tree)/(FILENR_MUL_FAC/10) == filenr );
assert( (o->GalaxyIndex - g->GalaxyNr -(FILENR_MUL_FAC/10)*filenr) / TREE_MUL_FAC == tree );
assert( o->GalaxyIndex - TREE_MUL_FAC*tree - (FILENR_MUL_FAC/10)*filenr == g->GalaxyNr );
o->CentralGalaxyIndex = HaloGal[HaloAux[Halo[g->HaloNr].FirstHaloInFOFgroup].FirstGalaxy].GalaxyNr + TREE_MUL_FAC * tree + (FILENR_MUL_FAC/10) * filenr;
}
else
{
assert( g->GalaxyNr < TREE_MUL_FAC ); // breaking tree size assumption
assert(tree < FILENR_MUL_FAC/TREE_MUL_FAC);
o->GalaxyIndex = g->GalaxyNr + TREE_MUL_FAC * tree + FILENR_MUL_FAC * filenr;
assert( (o->GalaxyIndex - g->GalaxyNr - TREE_MUL_FAC*tree)/FILENR_MUL_FAC == filenr );
assert( (o->GalaxyIndex - g->GalaxyNr -FILENR_MUL_FAC*filenr) / TREE_MUL_FAC == tree );
assert( o->GalaxyIndex - TREE_MUL_FAC*tree - FILENR_MUL_FAC*filenr == g->GalaxyNr );
o->CentralGalaxyIndex = HaloGal[HaloAux[Halo[g->HaloNr].FirstHaloInFOFgroup].FirstGalaxy].GalaxyNr + TREE_MUL_FAC * tree + FILENR_MUL_FAC * filenr;
}
o->SAGEHaloIndex = g->HaloNr;
o->SAGETreeIndex = tree;
o->SimulationHaloIndex = Halo[g->HaloNr].MostBoundID;
o->mergeType = g->mergeType;
o->mergeIntoID = g->mergeIntoID;
o->mergeIntoSnapNum = g->mergeIntoSnapNum;
o->dT = g->dT * UnitTime_in_s / SEC_PER_MEGAYEAR;
for(j = 0; j < 3; j++)
{
o->Pos[j] = g->Pos[j];
o->Vel[j] = g->Vel[j];
o->Spin[j] = Halo[g->HaloNr].Spin[j];
}
o->Len = g->Len;
o->Mvir = g->Mvir;
o->CentralMvir = get_virial_mass(Halo[g->HaloNr].FirstHaloInFOFgroup);
o->Rvir = get_virial_radius(g->HaloNr); // output the actual Rvir, not the maximum Rvir
o->Vvir = get_virial_velocity(g->HaloNr); // output the actual Vvir, not the maximum Vvir
o->Vmax = g->Vmax;
o->VelDisp = Halo[g->HaloNr].VelDisp;
o->ColdGas = g->ColdGas;
o->StellarMass = g->StellarMass;
o->BulgeMass = g->BulgeMass;
o->HotGas = g->HotGas;
o->EjectedMass = g->EjectedMass;
o->BlackHoleMass = g->BlackHoleMass;
o->ICS = g->ICS;
o->MetalsColdGas = g->MetalsColdGas;
o->MetalsStellarMass = g->MetalsStellarMass;
o->MetalsBulgeMass = g->MetalsBulgeMass;
o->MetalsHotGas = g->MetalsHotGas;
o->MetalsEjectedMass = g->MetalsEjectedMass;
o->MetalsICS = g->MetalsICS;
o->SfrDisk = 0.0;
o->SfrBulge = 0.0;
o->SfrDiskZ = 0.0;
o->SfrBulgeZ = 0.0;
// NOTE: in Msun/yr
for(step = 0; step < STEPS; step++)
{
o->SfrDisk += g->SfrDisk[step] * UnitMass_in_g / UnitTime_in_s * SEC_PER_YEAR / SOLAR_MASS / STEPS;
o->SfrBulge += g->SfrBulge[step] * UnitMass_in_g / UnitTime_in_s * SEC_PER_YEAR / SOLAR_MASS / STEPS;
if(g->SfrDiskColdGas[step] > 0.0)
o->SfrDiskZ += g->SfrDiskColdGasMetals[step] / g->SfrDiskColdGas[step] / STEPS;
if(g->SfrBulgeColdGas[step] > 0.0)
o->SfrBulgeZ += g->SfrBulgeColdGasMetals[step] / g->SfrBulgeColdGas[step] / STEPS;
}
o->DiskScaleRadius = g->DiskScaleRadius;
if (g->Cooling > 0.0)
o->Cooling = log10(g->Cooling * UnitEnergy_in_cgs / UnitTime_in_s);
else
o->Cooling = 0.0;
if (g->Heating > 0.0)
o->Heating = log10(g->Heating * UnitEnergy_in_cgs / UnitTime_in_s);
else
o->Heating = 0.0;
o->QuasarModeBHaccretionMass = g->QuasarModeBHaccretionMass;
o->TimeOfLastMajorMerger = g->TimeOfLastMajorMerger * UnitTime_in_Megayears;
o->TimeOfLastMinorMerger = g->TimeOfLastMinorMerger * UnitTime_in_Megayears;
o->OutflowRate = g->OutflowRate * UnitMass_in_g / UnitTime_in_s * SEC_PER_YEAR / SOLAR_MASS;
//infall properties
if(g->Type != 0)
{
o->infallMvir = g->infallMvir;
o->infallVvir = g->infallVvir;
o->infallVmax = g->infallVmax;
}
else
{
o->infallMvir = 0.0;
o->infallVvir = 0.0;
o->infallVmax = 0.0;
}
}
int join_galaxies_of_progenitors(int halonr, int ngalstart)
{
int ngal, prog, mother_halo=-1, i, j, first_occupied, lenmax, lenoccmax, centralgal;
double previousMvir, previousVvir, previousVmax;
int step;
lenmax = 0;
lenoccmax = 0;
first_occupied = Halo[halonr].FirstProgenitor;
prog = Halo[halonr].FirstProgenitor;
if(prog >=0)
if(HaloAux[prog].NGalaxies > 0)
lenoccmax = -1;
// Find most massive progenitor that contains an actual galaxy
// Maybe FirstProgenitor never was FirstHaloInFOFGroup and thus has no galaxy
while(prog >= 0)
{
if(Halo[prog].Len > lenmax)
{
lenmax = Halo[prog].Len;
mother_halo = prog;
}
if(lenoccmax != -1 && Halo[prog].Len > lenoccmax && HaloAux[prog].NGalaxies > 0)
{
lenoccmax = Halo[prog].Len;
first_occupied = prog;
}
prog = Halo[prog].NextProgenitor;
}
ngal = ngalstart;
prog = Halo[halonr].FirstProgenitor;
while(prog >= 0)
{
for(i = 0; i < HaloAux[prog].NGalaxies; i++)
{
assert(ngal < FoF_MaxGals);
// This is the cruical line in which the properties of the progenitor galaxies
// are copied over (as a whole) to the (temporary) galaxies Gal[xxx] in the current snapshot
// After updating their properties and evolving them
// they are copied to the end of the list of permanent galaxies HaloGal[xxx]
Gal[ngal] = HaloGal[HaloAux[prog].FirstGalaxy + i];
Gal[ngal].HaloNr = halonr;
Gal[ngal].dT = -1.0;
// this deals with the central galaxies of (sub)halos
if(Gal[ngal].Type == 0 || Gal[ngal].Type == 1)
{
// this halo shouldn't hold a galaxy that has already merged; remove it from future processing
if(Gal[ngal].mergeType != 0)
{
Gal[ngal].Type = 3;
continue;
}
// remember properties from the last snapshot
previousMvir = Gal[ngal].Mvir;
previousVvir = Gal[ngal].Vvir;
previousVmax = Gal[ngal].Vmax;
if(prog == first_occupied)
{
// update properties of this galaxy with physical properties of halo
Gal[ngal].MostBoundID = Halo[halonr].MostBoundID;
for(j = 0; j < 3; j++)
{
Gal[ngal].Pos[j] = Halo[halonr].Pos[j];
Gal[ngal].Vel[j] = Halo[halonr].Vel[j];
}
Gal[ngal].Len = Halo[halonr].Len;
Gal[ngal].Vmax = Halo[halonr].Vmax;
Gal[ngal].deltaMvir = get_virial_mass(halonr) - Gal[ngal].Mvir;
if(get_virial_mass(halonr) > Gal[ngal].Mvir)
{
Gal[ngal].Rvir = get_virial_radius(halonr); // use the maximum Rvir in model
Gal[ngal].Vvir = get_virial_velocity(halonr); // use the maximum Vvir in model
}
Gal[ngal].Mvir = get_virial_mass(halonr);
Gal[ngal].Cooling = 0.0;
Gal[ngal].Heating = 0.0;
Gal[ngal].QuasarModeBHaccretionMass = 0.0;
Gal[ngal].OutflowRate = 0.0;
Gal[ngal].Lx_bol = 0.0;
for(step = 0; step < STEPS; step++)
{
Gal[ngal].SfrDisk[step] = Gal[ngal].SfrBulge[step] = 0.0;
Gal[ngal].SfrDiskColdGas[step] = Gal[ngal].SfrDiskColdGasMetals[step] = 0.0;
Gal[ngal].SfrBulgeColdGas[step] = Gal[ngal].SfrBulgeColdGasMetals[step] = 0.0;
}
if(halonr == Halo[halonr].FirstHaloInFOFgroup)
{
// a central galaxy
Gal[ngal].mergeType = 0;
Gal[ngal].mergeIntoID = -1;
Gal[ngal].MergTime = 999.9;
Gal[ngal].DiskScaleRadius = get_disk_radius(halonr, ngal);
Gal[ngal].Type = 0;
}
else
{
// a satellite with subhalo
Gal[ngal].mergeType = 0;
Gal[ngal].mergeIntoID = -1;
if(Gal[ngal].Type == 0) // remember the infall properties before becoming a subhalo
{
Gal[ngal].infallMvir = previousMvir;
Gal[ngal].infallVvir = previousVvir;
Gal[ngal].infallVmax = previousVmax;
}
if(Gal[ngal].Type == 0 || Gal[ngal].MergTime > 999.0)
// here the galaxy has gone from type 1 to type 2 or otherwise doesn't have a merging time.
Gal[ngal].MergTime = estimate_merging_time(halonr, Halo[halonr].FirstHaloInFOFgroup, ngal);
Gal[ngal].Type = 1;
}
}
else
{
// an orhpan satellite galaxy - these will merge or disrupt within the current timestep
Gal[ngal].deltaMvir = -1.0*Gal[ngal].Mvir;
Gal[ngal].Mvir = 0.0;
if(Gal[ngal].MergTime > 999.0 || Gal[ngal].Type == 0)
{
// here the galaxy has gone from type 0 to type 2 - merge it!
Gal[ngal].MergTime = 0.0;
Gal[ngal].infallMvir = previousMvir;
Gal[ngal].infallVvir = previousVvir;
Gal[ngal].infallVmax = previousVmax;
}
Gal[ngal].Type = 2;
}
}
ngal++;
}
prog = Halo[prog].NextProgenitor;
}
if(ngal == 0)
{
// We have no progenitors with galaxies. This means we create a new galaxy.
init_galaxy(ngal, halonr);
ngal++;
}
// Per Halo there can be only one Type 0 or 1 galaxy, all others are Type 2 (orphan)
// In fact, this galaxy is very likely to be the first galaxy in the halo if
// first_occupied==FirstProgenitor and the Type0/1 galaxy in FirstProgenitor was also the first one
// This cannot be guaranteed though for the pathological first_occupied!=FirstProgenitor case
for(i = ngalstart, centralgal = -1; i < ngal; i++)
{
if(Gal[i].Type == 0 || Gal[i].Type == 1)
{
assert(centralgal == -1);
centralgal = i;
}
}
for(i = ngalstart; i < ngal; i++)
Gal[i].CentralGal = centralgal;
return ngal;
}