2 files changed, 7 insertions, 15 deletions
diff --git a/fg21sim/extragalactic/clusters/halo.py b/fg21sim/extragalactic/clusters/halo.py
index a6dfbb3..847f57d 100644
--- a/fg21sim/extragalactic/clusters/halo.py
+++ b/fg21sim/extragalactic/clusters/halo.py
@@ -236,17 +236,9 @@ class RadioHalo:
     def radius(self):
         """
         The estimated radius for the simulated radio halo.
-
-        NOTE
-        ----
-        The halo radius is assumed to be the virial radius of the falling
-        sub-cluster.  See ``helper.radius_halo()`` for more details.
-
         Unit: [kpc]
         """
-        r_halo = helper.radius_halo(self.M_main, self.M_sub,
-                                    self.z_merger, configs=self.configs)
-        return r_halo
+        return helper.radius_halo(self.M_obs, self.z_obs, configs=self.configs)
 
     @property
     def angular_radius(self):
diff --git a/fg21sim/extragalactic/clusters/helper.py b/fg21sim/extragalactic/clusters/helper.py
index 88c566a..39cee12 100644
--- a/fg21sim/extragalactic/clusters/helper.py
+++ b/fg21sim/extragalactic/clusters/helper.py
@@ -89,23 +89,23 @@ def radius_virial(mass, z=0.0):
     return R_vir
 
 
-def radius_halo(M_main, M_sub, z=0.0, configs=CONFIGS):
+def radius_halo(mass, z=0.0, configs=CONFIGS):
     """
-    Calculate the (predicted) radius of (giant) radio halo.
+    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 ≅ R_vir / 3
-    where R_vir the virial radius of the merged cluster.
+    where R_vir the virial radius of the merged (observed) cluster.
 
     Reference: [vazza2011],Sec.(3.6)
 
     Parameters
     ----------
-    M_main, M_sub : float, `~numpy.ndarray`
-        Total (virial) masses of the main and sub clusters
+    mass : float, `~numpy.ndarray`
+        Cluster virial mass.
         Unit: [Msun]
     z : float, `~numpy.ndarray`, optional
         Redshift
@@ -120,7 +120,7 @@ def radius_halo(M_main, M_sub, z=0.0, configs=CONFIGS):
     # Turbulence injection scale factor
     key = "extragalactic/halos/f_lturb"
     f_lturb = configs.getn(key)
-    R_halo = f_lturb * radius_virial(mass=M_main+M_sub, z=z)  # [kpc]
+    R_halo = f_lturb * radius_virial(mass=mass, z=z)  # [kpc]
     return R_halo