diff --git a/galaxy.py b/galaxy.py
index 076f4a0..8055d04 100644
--- a/galaxy.py
+++ b/galaxy.py
@@ -133,23 +133,29 @@ def ring_analysis(pp, r=4, dr=0.5, dphi=0.125, z=0, dz=0.5, do_mean=True):
 
 def get_time_from_relax(pp):
     pp.load_parts()
-    epoch = pp.parts["epoch"].copy()
-    epoch *= pp.info["unit_time"].express(U.Myr)
-    trelax = np.min(epoch[epoch > 0])
-    tfromrelax = np.max(epoch - trelax)
+    try:
+        epoch = pp.parts["epoch"].copy()
+        epoch *= pp.info["unit_time"].express(U.Myr)
+        trelax = np.min(epoch[epoch > 0])
+        tfromrelax = np.max(epoch - trelax)
+    except KeyError:
+        tfromrelax = 0.0
     return tfromrelax
 
 
 def get_last_sfr(pp):
     pp.load_parts()
-    epoch = pp.parts["epoch"].copy()
-    epoch *= pp.info["unit_time"].express(U.year)
-    mass = pp.parts["mass"].copy()
-    mass *= pp.info["unit_mass"].express(U.Msun)
-    mask = epoch > 0
-    masstot, time = np.histogram(epoch[mask], weights=mass[mask], bins=100)
-    dtime = np.diff(time)
-    sfr = masstot[-1] / dtime[-1]
+    try:
+        epoch = pp.parts["epoch"].copy()
+        epoch *= pp.info["unit_time"].express(U.year)
+        mass = pp.parts["mass"].copy()
+        mass *= pp.info["unit_mass"].express(U.Msun)
+        mask = epoch > 0
+        masstot, time = np.histogram(epoch[mask], weights=mass[mask], bins=100)
+        dtime = np.diff(time)
+        sfr = masstot[-1] / dtime[-1]
+    except KeyError:
+        sfr = 0.0
     return sfr