diff --git a/examples/ExternalGravity/makeIC.py b/examples/ExternalGravity/makeIC.py
index cbe565af29f0ec930edc2b87cfbc04b9ffe59bd5..29a96b5b8258a14fa95418f36847a3004871d6d3 100644
--- a/examples/ExternalGravity/makeIC.py
+++ b/examples/ExternalGravity/makeIC.py
@@ -1,7 +1,7 @@
 ###############################################################################
  # This file is part of SWIFT.
- # Copyright (c) 2013 Pedro Gonnet (pedro.gonnet@durham.ac.uk),
- #                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ # Copyright (c) 2016 John A. Regan (john.a.regan@durham.ac.uk)
+ #                    Tom Theuns (tom.theuns@durham.ac.uk)
  # 
  # This program is free software: you can redistribute it and/or modify
  # it under the terms of the GNU Lesser General Public License as published
diff --git a/examples/TestingGravity/makeIC.py b/examples/TestingGravity/makeIC.py
index cbe565af29f0ec930edc2b87cfbc04b9ffe59bd5..29a96b5b8258a14fa95418f36847a3004871d6d3 100644
--- a/examples/TestingGravity/makeIC.py
+++ b/examples/TestingGravity/makeIC.py
@@ -1,7 +1,7 @@
 ###############################################################################
  # This file is part of SWIFT.
- # Copyright (c) 2013 Pedro Gonnet (pedro.gonnet@durham.ac.uk),
- #                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ # Copyright (c) 2016 John A. Regan (john.a.regan@durham.ac.uk)
+ #                    Tom Theuns (tom.theuns@durham.ac.uk)
  # 
  # This program is free software: you can redistribute it and/or modify
  # it under the terms of the GNU Lesser General Public License as published
diff --git a/examples/main.c b/examples/main.c
index 052d425ea5e3fa8bdf8f13161478534716692175..05f1c244123a1b17ed7c8cdf0489df14f62bd02f 100644
--- a/examples/main.c
+++ b/examples/main.c
@@ -3,6 +3,9 @@
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk),
  *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
  *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *                    Angus Lepper (angus.lepper@ed.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/cell.c b/src/cell.c
index 61acfaaea7a0af01a78ab773541564e9a2723f4e..c22ab310d76efbc857ef4801ac185d771a0d9e58 100644
--- a/src/cell.c
+++ b/src/cell.c
@@ -1,6 +1,10 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/cell.h b/src/cell.h
index 607073660946fac1acda5cea512ed8adb4aa5218..fbdaa928bda51aa76c149df1249d982fbeef64c3 100644
--- a/src/cell.h
+++ b/src/cell.h
@@ -1,6 +1,10 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/const.h b/src/const.h
index 31039457275140f8b1161c102abc632da226770e..8b69eb12e4f66b6661a623d9953a5df38a192732 100644
--- a/src/const.h
+++ b/src/const.h
@@ -58,6 +58,7 @@
   0.57735f /* Opening criteria, which is the ratio of the \
               cell distance over the cell width. */
 
+#define const_G 6.672e-8f             /* Gravitational constant. */
 #define const_epsilon 0.0014f         /* Gravity blending distance. */
 #define const_iepsilon 714.285714286f /* Inverse gravity blending distance. */
 #define const_iepsilon2 (const_iepsilon* const_iepsilon)
@@ -80,11 +81,4 @@
 #define const_unit_mass_in_cgs (SOLAR_MASS_IN_CGS)       /* solar mass */
 #define const_unit_velocity_in_cgs (1e5)                 /* km/s */
 
-/* Derived constants */
-#define const_unit_time_in_cgs \
-  (const_unit_length_in_cgs / const_unit_velocity_in_cgs)
-#define const_G                                              \
-  ((NEWTON_GRAVITY_CGS* const_unit_mass_in_cgs /             \
-    (const_unit_velocity_in_cgs* const_unit_velocity_in_cgs* \
-         const_unit_length_in_cgs)))
 #endif /* SWIFT_CONST_H */
diff --git a/src/engine.c b/src/engine.c
index 354a2d623bc083a8465f278f8a6dac46c13b1039..388ffd3546bbb3461f0a05c0774e2d4a799a3801 100644
--- a/src/engine.c
+++ b/src/engine.c
@@ -1,7 +1,11 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
  *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *                    Angus Lepper (angus.lepper@ed.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/engine.h b/src/engine.h
index f63fed8e8fff075de245283fe9d4ef3e1a27586e..79b2f61f31d33f3c3d7d5aa349e4df6d913df82c 100644
--- a/src/engine.h
+++ b/src/engine.h
@@ -1,6 +1,11 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *                    Angus Lepper (angus.lepper@ed.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/gravity/Default/gravity.h b/src/gravity/Default/gravity.h
index 5bc516735d679f72206a8eb37e48626d3aa5a9de..0462846716df9a7e20c59577a08e880ee9115020 100644
--- a/src/gravity/Default/gravity.h
+++ b/src/gravity/Default/gravity.h
@@ -1,6 +1,7 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Coypright (c) 2015 Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2016 Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/runner.c b/src/runner.c
index d5a3edfac2ff5282a72623b0b386696fd435821f..205287efe7bbca5bd23950d8a02cb46886025529 100644
--- a/src/runner.c
+++ b/src/runner.c
@@ -1,6 +1,10 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/runner.h b/src/runner.h
index ff2f93db6eae9d9e85cd9c3de6f398ed0f64c681..f052bb57cdfc92a632cc4143d74250e7b6f6e847 100644
--- a/src/runner.h
+++ b/src/runner.h
@@ -1,6 +1,10 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/space.c b/src/space.c
index a937b49a8201f0a93468dbfd8fd889473530f96f..1de35a16b04b45b14c9e83eca5dfb65daed4e0a2 100644
--- a/src/space.c
+++ b/src/space.c
@@ -1,21 +1,25 @@
 /*******************************************************************************
-* This file is part of SWIFT.
-* Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
-*
-* This program is free software: you can redistribute it and/or modify
-* it under the terms of the GNU Lesser General Public License as published
-* by the Free Software Foundation, either version 3 of the License, or
-* (at your option) any later version.
-*
-* This program is distributed in the hope that it will be useful,
-* but WITHOUT ANY WARRANTY; without even the implied warranty of
-* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-* GNU General Public License for more details.
-*
-* You should have received a copy of the GNU Lesser General Public License
-* along with this program.  If not, see <http://www.gnu.org/licenses/>.
-*
-******************************************************************************/
+ * This file is part of SWIFT.
+ * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published
+ * by the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ ******************************************************************************/
 
 /* Config parameters. */
 #include "../config.h"
diff --git a/src/space.h b/src/space.h
index e761595838ae78b0d8a67cca676cfa59f3f700f6..f322f8d0cb21b5244222d868b92cbeea956c171d 100644
--- a/src/space.h
+++ b/src/space.h
@@ -1,6 +1,10 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/task.c b/src/task.c
index 1ad4b95be8e7245c7a971f17244b4569d4f6ce2a..d9bc7ee824d50506cf66da0b01514cc04ac80e5f 100644
--- a/src/task.c
+++ b/src/task.c
@@ -1,6 +1,10 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/task.h b/src/task.h
index 3e641ad2b08f373ca60557e32b6290ee272faeca..26565f37f6fb99773dab1c1ea76b0c116c8c0fed 100644
--- a/src/task.h
+++ b/src/task.h
@@ -2,6 +2,9 @@
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
  *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2015 Peter W. Draper (p.w.draper@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/timers.c b/src/timers.c
index 2501d347c8cea608650ece4c2883dab85ceee058..b621d27c90902f06c3760cbef6a88237a2b3b95b 100644
--- a/src/timers.c
+++ b/src/timers.c
@@ -1,6 +1,9 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published
diff --git a/src/timers.h b/src/timers.h
index 7a5fe868ba6f16583d8ae80cb9880a1258fbd5a8..bf288d73929bd664992ef3da6d531d77aa85ac3b 100644
--- a/src/timers.h
+++ b/src/timers.h
@@ -1,6 +1,9 @@
 /*******************************************************************************
  * This file is part of SWIFT.
  * Copyright (c) 2012 Pedro Gonnet (pedro.gonnet@durham.ac.uk)
+ *                    Matthieu Schaller (matthieu.schaller@durham.ac.uk)
+ *               2016 John A. Regan (john.a.regan@durham.ac.uk)
+ *                    Tom Theuns (tom.theuns@durham.ac.uk)
  *
  * This program is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published