add uniform in source frame prior

bilby/gw/prior.py

@@ -159,6 +159,22 @@ class UniformComovingVolume(Cosmological):
         return zs, p_dz
 
 
+class UniformSourceFrame(Cosmological):
+    """
+    Prior for redshift which is uniform in comoving volume and source frame
+    time.
+
+    For redshift this is p(z) \propto dVc/dz 1 / (1 + z), where the extra 1+z
+    is due to doppler shifting of the source frame time.
+    """
+
+    def _get_redshift_arrays(self):
+        zs = np.linspace(self._minimum['redshift'] * 0.99,
+                         self._maximum['redshift'] * 1.01, 1000)
+        p_dz = self.cosmology.differential_comoving_volume(zs).value / (1 + zs)
+        return zs, p_dz
+
+
 class AlignedSpin(Interped):
 
     def __init__(self, a_prior=Uniform(0, 1), z_prior=Uniform(-1, 1),

bilby/gw/prior_files/GW150914.prior

@@ -8,7 +8,7 @@ tilt_1 = Sine(name='tilt_1', periodic_boundary=False)
 tilt_2 = Sine(name='tilt_2', periodic_boundary=False)
 phi_12 = Uniform(name='phi_12', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 phi_jl = Uniform(name='phi_jl', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
-luminosity_distance = bilby.gw.prior.UniformComovingVolume(name='luminosity_distance', minimum=1e2, maximum=1e3, unit='Mpc', periodic_boundary=False)
+luminosity_distance = bilby.gw.prior.UniformSourceFrame(name='luminosity_distance', minimum=1e2, maximum=1e3, unit='Mpc', periodic_boundary=False)
 dec = Cosine(name='dec', periodic_boundary=False)
 ra = Uniform(name='ra', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 theta_jn = Sine(name='theta_jn', periodic_boundary=False)

bilby/gw/prior_files/aligned_spin_binary_black_holes.prior

@@ -11,7 +11,7 @@ mass_ratio = Constraint(name='mass_ratio', minimum=0.125, maximum=1)
 # symmetric_mass_ratio =  Uniform(name='symmetric_mass_ratio', minimum=8 / 81, maximum=0.25, periodic_boundary=False)
 chi_1 = bilby.gw.prior.AlignedSpin(name='chi_1', a_prior=Uniform(minimum=0, maximum=0.8), periodic_boundary=False)
 chi_2 = bilby.gw.prior.AlignedSpin(name='chi_2', a_prior=Uniform(minimum=0, maximum=0.8), periodic_boundary=False)
-luminosity_distance = bilby.gw.prior.UniformComovingVolume(name='luminosity_distance', minimum=1e2, maximum=5e3, unit='Mpc', periodic_boundary=False)
+luminosity_distance = bilby.gw.prior.UniformSourceFrame(name='luminosity_distance', minimum=1e2, maximum=5e3, unit='Mpc', periodic_boundary=False)
 dec = Cosine(name='dec', periodic_boundary=False)
 ra = Uniform(name='ra', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 theta_jn = Sine(name='theta_jn', periodic_boundary=False)

bilby/gw/prior_files/binary_black_holes.prior

@@ -17,7 +17,7 @@ tilt_2 = Sine(name='tilt_2', periodic_boundary=False)
 # cos_tilt_2 = Uniform(name='cos_tilt_2', minimum=-1, maximum=1, periodic_boundary=False)
 phi_12 = Uniform(name='phi_12', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 phi_jl = Uniform(name='phi_jl', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
-luminosity_distance = bilby.gw.prior.UniformComovingVolume(name='luminosity_distance', minimum=1e2, maximum=5e3, unit='Mpc', periodic_boundary=False)
+luminosity_distance = bilby.gw.prior.UniformSourceFrame(name='luminosity_distance', minimum=1e2, maximum=5e3, unit='Mpc', periodic_boundary=False)
 dec = Cosine(name='dec', periodic_boundary=False)
 ra = Uniform(name='ra', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 theta_jn = Sine(name='theta_jn', periodic_boundary=False)

bilby/gw/prior_files/binary_neutron_stars.prior

@@ -11,7 +11,7 @@ mass_ratio = Constraint(name='mass_ratio', minimum=0.125, maximum=1)
 # symmetric_mass_ratio = Uniform(name='symmetric_mass_ratio', minimum=0.22, maximum=0.25, periodic_boundary=False)
 chi_1 = bilby.gw.prior.AlignedSpin(a_prior=Uniform(0, 0.05), z_prior=Uniform(-1, 1), name='chi_1', latex_label='$\\chi_1$', periodic_boundary=False)
 chi_2 = bilby.gw.prior.AlignedSpin(a_prior=Uniform(0, 0.05), z_prior=Uniform(-1, 1), name='chi_2', latex_label='$\\chi_2$', periodic_boundary=False)
-luminosity_distance = bilby.gw.prior.UniformComovingVolume(name='luminosity_distance', minimum=10, maximum=500, unit='Mpc', periodic_boundary=False)
+luminosity_distance = bilby.gw.prior.UniformSourceFrame(name='luminosity_distance', minimum=10, maximum=500, unit='Mpc', periodic_boundary=False)
 dec = Cosine(name='dec', periodic_boundary=False)
 ra = Uniform(name='ra', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 theta_jn = Sine(name='theta_jn', periodic_boundary=False)

test/prior_files/binary_black_holes.prior

@@ -17,7 +17,7 @@ tilt_2 = Sine(name='tilt_2', periodic_boundary=False)
 # cos_tilt_2 = Uniform(name='cos_tilt_2', minimum=-1, maximum=1, periodic_boundary=False)
 phi_12 = Uniform(name='phi_12', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 phi_jl = Uniform(name='phi_jl', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
-luminosity_distance = bilby.gw.prior.UniformComovingVolume(name='luminosity_distance', minimum=1e2, maximum=5e3, unit='Mpc', periodic_boundary=False)
+luminosity_distance = bilby.gw.prior.UniformSourceFrame(name='luminosity_distance', minimum=1e2, maximum=5e3, unit='Mpc', periodic_boundary=False)
 dec = Cosine(name='dec', periodic_boundary=False)
 ra = Uniform(name='ra', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 theta_jn = Sine(name='theta_jn', periodic_boundary=False)

test/prior_files/binary_neutron_stars.prior

@@ -11,7 +11,7 @@ mass_ratio = Constraint(name='mass_ratio', minimum=0.125, maximum=1)
 # symmetric_mass_ratio = Uniform(name='symmetric_mass_ratio', minimum=0.22, maximum=0.25, periodic_boundary=False)
 chi_1 = bilby.gw.prior.AlignedSpin(a_prior=Uniform(0, 0.05), z_prior=Uniform(-1, 1), name='chi_1', latex_label='$\\chi_1$', periodic_boundary=False)
 chi_2 = bilby.gw.prior.AlignedSpin(a_prior=Uniform(0, 0.05), z_prior=Uniform(-1, 1), name='chi_2', latex_label='$\\chi_2$', periodic_boundary=False)
-luminosity_distance = bilby.gw.prior.UniformComovingVolume(name='luminosity_distance', minimum=10, maximum=500, unit='Mpc', periodic_boundary=False)
+luminosity_distance = bilby.gw.prior.UniformSourceFrame(name='luminosity_distance', minimum=10, maximum=500, unit='Mpc', periodic_boundary=False)
 dec = Cosine(name='dec', periodic_boundary=False)
 ra = Uniform(name='ra', minimum=0, maximum=2 * np.pi, periodic_boundary=True)
 theta_jn = Sine(name='theta_jn', periodic_boundary=False)

test/prior_test.py

@@ -166,6 +166,7 @@ class TestPriorClasses(unittest.TestCase):
             bilby.core.prior.Uniform(name='test', unit='unit', minimum=0, maximum=1),
             bilby.core.prior.LogUniform(name='test', unit='unit', minimum=5e0, maximum=1e2),
             bilby.gw.prior.UniformComovingVolume(name='redshift', minimum=0.1, maximum=1.0),
+            bilby.gw.prior.UniformSourceFrame(name='redshift', minimum=0.1, maximum=1.0),
             bilby.core.prior.Sine(name='test', unit='unit'),
             bilby.core.prior.Cosine(name='test', unit='unit'),
             bilby.core.prior.Interped(name='test', unit='unit', xx=np.linspace(0, 10, 1000),
@@ -566,7 +567,7 @@ class TestPriorDict(unittest.TestCase):
                 name='phi_12', minimum=0, maximum=2 * np.pi, periodic_boundary=True),
             phi_jl=bilby.core.prior.Uniform(
                 name='phi_jl', minimum=0, maximum=2 * np.pi, periodic_boundary=True),
-            luminosity_distance=bilby.gw.prior.UniformComovingVolume(
+            luminosity_distance=bilby.gw.prior.UniformSourceFrame(
                 name='luminosity_distance', minimum=1e2,
                 maximum=5e3, unit='Mpc', periodic_boundary=False),
             dec=bilby.core.prior.Cosine(name='dec', periodic_boundary=False),
@@ -630,7 +631,7 @@ class TestPriorDict(unittest.TestCase):
                     name='phi_12', minimum=0, maximum=2 * np.pi, periodic_boundary=True),
                 phi_jl=bilby.core.prior.Uniform(
                     name='phi_jl', minimum=0, maximum=2 * np.pi, periodic_boundary=True),
-                luminosity_distance=bilby.gw.prior.UniformComovingVolume(
+                luminosity_distance=bilby.gw.prior.UniformSourceFrame(
                     name='luminosity_distance', minimum=1e2,
                     maximum=5e3, unit='Mpc', periodic_boundary=False),
                 dec=bilby.core.prior.Cosine(name='dec', periodic_boundary=False),