From b010b4c79d87f9364b2581fc0701e1dcfefd91fa Mon Sep 17 00:00:00 2001
From: Aaron LI <aly@aaronly.me>
Date: Wed, 19 Jul 2017 14:37:56 +0800
Subject: clusters/formation.py: Add method "_trace_main()"
Also update "simulate_megertree()" default to trace only the main cluster.
Signed-off-by: Aaron LI <aly@aaronly.me>
---
fg21sim/extragalactic/clusters/formation.py | 87 +++++++++++++++++++++++++----
1 file changed, 77 insertions(+), 10 deletions(-)
diff --git a/fg21sim/extragalactic/clusters/formation.py b/fg21sim/extragalactic/clusters/formation.py
index 6dbf58e..59c8cbe 100644
--- a/fg21sim/extragalactic/clusters/formation.py
+++ b/fg21sim/extragalactic/clusters/formation.py
@@ -169,23 +169,92 @@ class ClusterFormation:
dS = self.cdf_K_inv(r, dw)
return dS
- def simulate_mergertree(self):
+ def simulate_mergertree(self, main_only=True):
"""
Simulate the merger tree of this cluster by tracing its formation
using the PS formalism.
+ Parameters
+ ----------
+ main_only : bool, optional
+ Whether to only trace the forming history of the main
+ halo/cluster.
+ (default: True)
+
References: Ref.[1],Sec.(3.1)
"""
logger.info("Simulating cluster formation: " +
- "M0={:.3g}[Msun] from z={:.2f} ...".format(
- self.M0, self.z0))
- self.mtree = self._trace_formation(self.M0,
- dMc=self.merger_mass_min,
- _z=self.z0)
+ "M0={:.3g}[Msun] from z={:.2f} to z={zmax} ...".format(
+ self.M0, self.z0, zmax=self.zmax))
+ self.main_only = main_only
+ if main_only:
+ logger.info("Only trace the formation of the *main* cluster ...")
+ self.mtree = self._trace_main()
+ else:
+ logger.info("Trace formations of both main and sub cluster ...")
+ self.mtree = self._trace_formation(self.M0, _z=self.z0)
logger.info("Simulated cluster formation with merger tree")
return self.mtree
- def _trace_formation(self, M, dMc, _z=None):
+ def _trace_main(self):
+ """
+ Iteratively trace the merger and accretion events of the
+ main cluster/halo.
+ """
+ # Initial properties
+ zc = self.z0
+ Mc = self.M0
+ mtree = MergerTree(data={"mass": Mc,
+ "z": zc,
+ "age": self.cosmo.age(zc)})
+
+ while True:
+ # Whether to stop the trace
+ if self.zmax is not None and zc > self.zmax:
+ break
+ if Mc <= self.merger_mass_min:
+ break
+
+ # Trace the formation by simulate a merger/accretion event
+ # Notation: progenitor (*1) -> current (*2)
+
+ # Current properties
+ w2 = self.f_delta_c(z=zc)
+ S2 = self.f_sigma(Mc) ** 2
+ dw = 0.5 * self.f_dw_max(Mc)
+ dS = self.gen_dS(dw)
+ # Progenitor properties
+ z1 = self.calc_z(w2 + dw)
+ age1 = self.cosmo.age(z1)
+ S1 = S2 + dS
+ M1 = self.calc_mass(S1)
+ dM = Mc - M1
+
+ M_min = min(M1, dM)
+ if M_min <= self.merger_mass_min:
+ # Accretion
+ M_main = Mc - M_min
+ # NOTE: no sub node
+ else:
+ # Merger event
+ M_main = max(M1, dM)
+ M_sub = M_min
+ mtree.sub = MergerTree(data={"mass": M_sub,
+ "z": z1,
+ "age": age1})
+
+ # Update main cluster
+ mtree.main = MergerTree(data={"mass": M_main,
+ "z": z1,
+ "age": age1})
+
+ # Update for next iteration
+ Mc = M_main
+ zc = z1
+ mtree = mtree.main
+
+ return mtree
+
def _trace_formation(self, M, _z=None, zmax=None):
"""
Recursively trace the cluster formation and thus simulate its
@@ -194,12 +263,10 @@ class ClusterFormation:
z = 0.0 if _z is None else _z
node_data = {"mass": M, "z": z, "age": self.cosmo.age(z)}
+ # Whether to stop the trace
if self.zmax is not None and z > self.zmax:
- # Stop the trace
return MergerTree(data=node_data)
-
if M <= self.merger_mass_min:
- # Stop the trace
return MergerTree(data=node_data)
# Trace the formation by simulate a merger/accretion event
--
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