diff options
Diffstat (limited to 'fg21sim/extragalactic')
| -rw-r--r-- | fg21sim/extragalactic/clusters/formation.py | 75 |
1 files changed, 34 insertions, 41 deletions
diff --git a/fg21sim/extragalactic/clusters/formation.py b/fg21sim/extragalactic/clusters/formation.py index 2089ef8..f8e1b27 100644 --- a/fg21sim/extragalactic/clusters/formation.py +++ b/fg21sim/extragalactic/clusters/formation.py @@ -32,13 +32,13 @@ logger = logging.getLogger(__name__) class ClusterFormation: """ - Simulate the cluster formation (i.e., merging history) using the extended - Press-Schechter formalism by Monte Carlo methods. + Simulate the cluster formation (i.e., merging history) by employing + the extended Press-Schechter formalism. Parameters ---------- M0 : float - Cluster mass at redshift z0 + Cluster total mass at redshift ``z0`` Unit: [Msun] z0 : float Redshift from where to simulate former merging history. @@ -49,14 +49,6 @@ class ClusterFormation: Minimum mass change to be regarded as a merger event instead of accretion. Unit: [Msun] - - Attributes - ---------- - mtree : `~MergerTree` - Merging history of this cluster. - recent_major_merger : dict, or None - An dictionary containing the properties of the found most recent - major merger event, or ``None`` if not found. """ def __init__(self, M0, z0, zmax=3.0, merger_mass_min=1e12): self.M0 = M0 # [Msun] @@ -78,8 +70,8 @@ class ClusterFormation: def f_sigma(self, mass): """ - Current rms density fluctuations within a sphere of specified - mass (unit: Msun). + Current r.m.s. density fluctuations within a sphere of the given + mean /dark matter/ mass (unit: [Msun]). It is generally sufficient to consider a power-law spectrum of density perturbations, which is consistent with the CDM models. @@ -127,9 +119,8 @@ class ClusterFormation: def calc_mass(self, S): """ - Calculate the mass corresponding to the given S. - - S = sigma(M)^2 + Calculate the /dark matter/ mass corresponding to the given S, + which is defined as: S = sigma(M)^2 References: Ref.[randall2002],Sec.(3) """ @@ -296,16 +287,17 @@ class ClusterFormation: def _trace_main(self): """ - Iteratively trace the merger and accretion events of the - main cluster/halo. + Iteratively trace the merger and accretion events of the main + cluster/halo only. """ # Initial properties zc = self.z0 - Mc = self.M0 - mtree_root = MergerTree(data={"mass": Mc, + Mc_cl = self.M0 # cluster total mass + Mc = Mc_cl * COSMO.baryon_fraction # dark matter mass + mtree_root = MergerTree(data={"mass": Mc_cl, "z": zc, "age": COSMO.age(zc)}) - logger.debug("[main] z=%.4f : mass=%g [Msun]" % (zc, Mc)) + logger.debug("[main] z=%.4f : mass=%g [Msun]" % (zc, Mc_cl)) mtree = mtree_root while True: @@ -333,37 +325,38 @@ class ClusterFormation: M_min = min(M1, dM) if M_min <= self.merger_mass_min: # Accretion - M_main = Mc - M_min + M_main_cl = (Mc - M_min) / COSMO.baryon_fraction # NOTE: no sub node else: - # Merger event - M_main = max(M1, dM) - M_sub = M_min - mtree.sub = MergerTree(data={"mass": M_sub, + # Merger + M_main_cl = max(M1, dM) / COSMO.baryon_fraction + M_sub_cl = M_min / COSMO.baryon_fraction + mtree.sub = MergerTree(data={"mass": M_sub_cl, "z": z1, "age": age1}) - logger.debug("[sub] z=%.4f : mass=%g [Msun]" % (z1, M_sub)) + logger.debug("[sub] z=%.4f : mass=%g [Msun]" % (z1, M_sub_cl)) # Update main cluster - mtree.main = MergerTree(data={"mass": M_main, + mtree.main = MergerTree(data={"mass": M_main_cl, "z": z1, "age": age1}) - logger.debug("[main] z=%.4f : mass=%g [Msun]" % (z1, M_main)) + logger.debug("[main] z=%.4f : mass=%g [Msun]" % (z1, M_main_cl)) # Update for next iteration - Mc = M_main + Mc_cl = M_main_cl zc = z1 mtree = mtree.main return mtree_root - def _trace_formation(self, M, _z=None, zmax=None): + def _trace_formation(self, M_cl, _z=None, zmax=None): """ - Recursively trace the cluster formation and thus simulate its - merger tree. + Recursively trace the cluster/halo formation and thus simulate + its merger tree. """ z = 0.0 if _z is None else _z - node_data = {"mass": M, "z": z, "age": COSMO.age(z)} + M = M_cl * COSMO.baryon_fraction # dark matter mass + node_data = {"mass": M_cl, "z": z, "age": COSMO.age(z)} # Whether to stop the trace if self.zmax is not None and z > self.zmax: @@ -388,18 +381,18 @@ class ClusterFormation: M_min = min(M1, dM) if M_min <= self.merger_mass_min: # Accretion - M_new = M - M_min + M_new_cl = (M - M_min) / COSMO.baryon_fraction return MergerTree( data=node_data, - main=self._trace_formation(M_new, _z=z1), + main=self._trace_formation(M_new_cl, _z=z1), sub=None ) else: - # Merger event - M_main = max(M1, dM) - M_sub = M_min + # Merger + M_main_cl = max(M1, dM) / COSMO.baryon_fraction + M_sub_cl = M_min / COSMO.baryon_fraction return MergerTree( data=node_data, - main=self._trace_formation(M_main, _z=z1), - sub=self._trace_formation(M_sub, _z=z1) + main=self._trace_formation(M_main_cl, _z=z1), + sub=self._trace_formation(M_sub_cl, _z=z1) ) |