From 3dfd7ce87f8d5351ca25c2392d69da30696b051c Mon Sep 17 00:00:00 2001
From: Aaron LI <aly@aaronly.me>
Date: Sat, 26 Jan 2019 21:07:53 +0800
Subject: clusters/halo: Rewrite _merger_time() to get the effective merger
If the acceleration durations of multiple mergers overlap, the one with
the largest efficiency (i.e., smallest tau_acc) is chosen.
---
fg21sim/extragalactic/clusters/halo.py | 32 ++++++++++++++++++++++++--------
1 file changed, 24 insertions(+), 8 deletions(-)
diff --git a/fg21sim/extragalactic/clusters/halo.py b/fg21sim/extragalactic/clusters/halo.py
index f66c347..4a62d3e 100644
--- a/fg21sim/extragalactic/clusters/halo.py
+++ b/fg21sim/extragalactic/clusters/halo.py
@@ -788,14 +788,6 @@ class RadioHaloAM(RadioHalo1M):
"t": self.t_merger[idx],
}
- def _merger_time(self, t):
- """
- Determine the beginning time of the merger event within which
- the given time is located.
- """
- merger = self._merger_event(t)
- return merger["t"]
-
def mass_merged(self, t):
"""
The mass of merged cluster at the given (cosmic) time.
@@ -845,6 +837,30 @@ class RadioHaloAM(RadioHalo1M):
rate = (mass0 - mass1) / (t0 - t1)
return (mass1 + rate * (t - t1))
+ def _merger_time(self, t):
+ """
+ Determine the beginning time of the merger event that is doing
+ effective acceleration at the given time.
+
+ At a certain time, there may be multiple past merger events with
+ different turbulence durations (``tau_turb``) and acceleration
+ efficiencies (``tau_acc``). Therefore, multiple mergers can cover
+ the given time. The one with the largest acceleration efficiency
+ (i.e., smallest ``tau_acc``) is chosen and its beginning time is
+ returned. Otherwise, the most recent merger event happened before
+ the given time is chosen.
+ """
+ mergers = [(tm, tm+self.duration_turb(tm), self.tau_acceleration(tm))
+ for tm in self.t_merger]
+ m_active = [(tm, tend, tau) for (tm, tend, tau) in mergers
+ if t >= tm and t < tend]
+ if m_active:
+ m_eff = min(m_active, key=lambda item: item[2])
+ return m_eff[0]
+ else:
+ m = self._merger_event(t)
+ return m["t"]
+
class RadioHalo:
"""
--
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