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-rw-r--r--fg21sim/extragalactic/clusters/formation.py44
-rw-r--r--fg21sim/extragalactic/clusters/main.py7
2 files changed, 19 insertions, 32 deletions
diff --git a/fg21sim/extragalactic/clusters/formation.py b/fg21sim/extragalactic/clusters/formation.py
index bfe2142..a48d68e 100644
--- a/fg21sim/extragalactic/clusters/formation.py
+++ b/fg21sim/extragalactic/clusters/formation.py
@@ -1,4 +1,4 @@
-# Copyright (c) 2017 Weitian LI <weitian@aaronly.me>
+# Copyright (c) 2017-2018 Weitian LI <weitian@aaronly.me>
# MIT license
"""
@@ -45,11 +45,6 @@ class ClusterFormation:
zmax : float, optional
The maximum redshift/age when to stop the formation trace.
Default: 3.0 (i.e., looking back time ~11.5 Gyr)
- ratio_major : float, optional
- The mass ratio of the main and sub clusters to define whether
- the merger is a major event or a minor one.
- If ``M_main/M_sub < ratio_major``, then it is a major merger event.
- Default: 3.0
merger_mass_min : float, optional
Minimum mass change to be regarded as a merger event instead of
accretion.
@@ -63,12 +58,10 @@ class ClusterFormation:
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, ratio_major=3.0,
- merger_mass_min=1e12):
+ def __init__(self, M0, z0, zmax=3.0, merger_mass_min=1e12):
self.M0 = M0 # [Msun]
self.z0 = z0
self.zmax = zmax
- self.ratio_major = ratio_major
self.merger_mass_min = merger_mass_min
@property
@@ -171,7 +164,7 @@ class ClusterFormation:
dS = self.cdf_K_inv(r, dw)
return dS
- def simulate_mergertree(self, main_only=True):
+ def simulate_mtree(self, main_only=True):
"""
Simulate the merger tree of this cluster by tracing its formation
using the PS formalism.
@@ -199,11 +192,18 @@ class ClusterFormation:
logger.debug("Simulated cluster formation with merger tree.")
return self.mtree
- @property
- def recent_major_merger(self):
+ def recent_major_merger(self, ratio_major=3.0):
"""
Identify and return the most recent major merger event.
+ Parameters
+ ----------
+ ratio_major : float, optional
+ The mass ratio of the main and sub clusters to define whether
+ the merger is a major event or a minor one.
+ If ``M_main/M_sub < ratio_major``, then it is a major merger.
+ Default: 3.0
+
Returns
-------
event :
@@ -240,16 +240,15 @@ class ClusterFormation:
return event
@property
- def max_merger(self):
+ def maximum_merger(self):
"""
The merger event corresponding to the biggest sub cluster, i.e.,
- the main cluster gains most mass.
+ the main cluster gains the most mass.
NOTE
----
- Generally, the above most recent major merger event, if identified,
- should also be maximum merger found here. Otherwise, a warning
- message is logged.
+ Sometimes, the maximum merger event found here is not an major
+ merger event.
Returns
-------
@@ -261,7 +260,6 @@ class ClusterFormation:
mtree = self.mtree
event_max = {"M_main": -1, "M_sub": -1, "R_mass": -1,
"z": -1, "age": -1}
- event_major = None # Record the most recent major merger event
while mtree and mtree.main:
if mtree.sub is None:
mtree = mtree.main
@@ -272,22 +270,12 @@ class ClusterFormation:
z = mtree.main.data["z"]
age = mtree.main.data["age"]
if (M_sub > event_max["M_sub"]):
- # Track the found maximum merger
event_max = {"M_main": M_main, "M_sub": M_sub,
"R_mass": M_main / M_sub,
"z": z, "age": age}
- if (event_major is None) and (M_main/M_sub <= self.ratio_major):
- # Most recent major merger event
- event_major = {"M_main": M_main, "M_sub": M_sub,
- "R_mass": M_main / M_sub,
- "z": z, "age": age}
-
# Continue
mtree = mtree.main
- if event_major and abs(event_major["z"]-event_max["z"]) > 1e-4:
- logger.warning("recent major merger != maximum merger")
-
if event_max["z"] <= 0:
logger.warning("no mergers occurred at all!!")
return None
diff --git a/fg21sim/extragalactic/clusters/main.py b/fg21sim/extragalactic/clusters/main.py
index a8e0576..9d3810d 100644
--- a/fg21sim/extragalactic/clusters/main.py
+++ b/fg21sim/extragalactic/clusters/main.py
@@ -213,14 +213,13 @@ class GalaxyClusters:
age0 = COSMO.age(z0)
zmax = COSMO.redshift(age0 - self.time_traceback)
clform = ClusterFormation(M0=M0, z0=z0, zmax=zmax,
- ratio_major=self.ratio_major,
merger_mass_min=self.merger_mass_min)
- clform.simulate_mergertree(main_only=True)
+ clform.simulate_mtree(main_only=True)
if self.use_max_merger:
# NOTE: may be ``None`` due to no mergers occurred at all!
- mmev = clform.max_merger
+ mmev = clform.maximum_merger
else:
- mmev = clform.recent_major_merger
+ mmev = clform.recent_major_merger(self.ratio_major)
if mmev:
mdata[i, :] = [mmev["M_main"], mmev["M_sub"],
mmev["z"], mmev["age"]]