clusters/halo: Update calculations of injection and halo radius

3 files changed, 17 insertions, 41 deletions

diff --git a/fg21sim/configs/config.spec b/fg21sim/configs/config.spec
index 5f9a512..0d7e7aa 100644
--- a/fg21sim/configs/config.spec
+++ b/fg21sim/configs/config.spec
@@ -386,11 +386,10 @@ stream = option("stderr", "stdout", "", default="stderr")
   #       timescale, therefore more efficient acceleration.
   f_acc = float(default=1.0, min=0.1, max=10)
 
-  # The turbulence is generally injected at the cluster center during
-  # a merger.  This option parameterize the turbulence injection scale
-  # to be a fraction of the virial radius of the cluster, which is also
-  # used to determine the radio halo size.
-  f_lturb = float(default=0.33, min=0.1, max=1.0)
+  # The factor that is multiplied to the stripping radius to approximate
+  # the turbulence injection radius, from which the radio halo size is
+  # estimated.
+  f_lturb = float(default=1.0, min=0.5, max=10)
 
   # An efficiency factor describing the effectiveness of plasma
   # instabilities (e.g., due to spatial or temporal intermittency).
diff --git a/fg21sim/extragalactic/clusters/halo.py b/fg21sim/extragalactic/clusters/halo.py
index eac9501..baa1a36 100644
--- a/fg21sim/extragalactic/clusters/halo.py
+++ b/fg21sim/extragalactic/clusters/halo.py
@@ -234,7 +234,7 @@ class RadioHalo:
         The estimated radius for the simulated radio halo.
         Unit: [kpc]
         """
-        return helper.radius_halo(self.M_obs, self.z_obs, configs=self.configs)
+        return self.injection_radius
 
     @property
     def angular_radius(self):
@@ -363,6 +363,18 @@ class RadioHalo:
         return tau
 
     @property
+    @lru_cache
+    def injection_radius(self):
+        """
+        The radius of the turbulence injection regions, and then the
+        injection scale: L_turb ~= 2*R_turb.
+        Unit: [kpc]
+        """
+        rs = helper.radius_stripping(self.M_main, self.M_sub, self.z_merger,
+                                     configs=self.configs)  # [kpc]
+        return self.f_lturb * rs
+
+    @property
     @lru_cache()
     def injection_rate(self):
         """
diff --git a/fg21sim/extragalactic/clusters/helper.py b/fg21sim/extragalactic/clusters/helper.py
index ecbb866..96800e4 100644
--- a/fg21sim/extragalactic/clusters/helper.py
+++ b/fg21sim/extragalactic/clusters/helper.py
@@ -129,41 +129,6 @@ def radius_virial(mass, z=0.0):
     return R_vir * AUC.cm2kpc  # [kpc]
 
 
-def radius_halo(mass, z=0.0, configs=CONFIGS):
-    """
-    Estimate the radius of (giant) radio halo.
-
-    NOTE
-    ----
-    The halo radius is estimated to be the same as the turbulence
-    injection scale, i.e.:
-        R_halo ≅ L_turb ≅ R_vir / 3
-    where R_vir the virial radius of the merged (observed) cluster.
-
-    Reference: [vazza2011],Sec.(3.6)
-
-    Parameters
-    ----------
-    mass : float, `~numpy.ndarray`
-        Cluster virial mass.
-        Unit: [Msun]
-    z : float, `~numpy.ndarray`, optional
-        Redshift
-        Default: 0.0 (i.e., present day)
-
-    Returns
-    -------
-    R_halo : float, `~numpy.ndarray`
-        Radius of the (simulated/predicted) giant radio halo
-        Unit: [kpc]
-    """
-    # Turbulence injection scale factor
-    key = "extragalactic/halos/f_lturb"
-    f_lturb = configs.getn(key)
-    R_halo = f_lturb * radius_virial(mass=mass, z=z)  # [kpc]
-    return R_halo
-
-
 def radius_stripping(M_main, M_sub, z, configs=CONFIGS):
     """
     Calculate the stripping radius of the in-falling sub-cluster, which