diff --git a/bilby/gw/conversion.py b/bilby/gw/conversion.py
index c2b842e8370f60e896f9774061b884dfc98f0775..82a4f2438786d90dc62f978fa22ba9eb674748af 100644
--- a/bilby/gw/conversion.py
+++ b/bilby/gw/conversion.py
@@ -254,7 +254,7 @@ def convert_to_lal_binary_neutron_star_parameters(parameters):
Mass: mass_1, mass_2
- Spin: chi_1, chi_2, tilt_1, tilt_2, phi_12, phi_jl
+ Spin: a_1, a_2, tilt_1, tilt_2, phi_12, phi_jl
Extrinsic: luminosity_distance, theta_jn, phase, ra, dec, geocent_time, psi
This involves popping a lot of things from parameters.
@@ -277,19 +277,6 @@ def convert_to_lal_binary_neutron_star_parameters(parameters):
converted_parameters, added_keys =\
convert_to_lal_binary_black_hole_parameters(converted_parameters)
- for idx in ['1', '2']:
- mag = 'a_{}'.format(idx)
- if mag in original_keys:
- tilt = 'tilt_{}'.format(idx)
- if tilt in original_keys:
- converted_parameters['chi_{}'.format(idx)] = (
- converted_parameters[mag] *
- np.cos(converted_parameters[tilt]))
- else:
- converted_parameters['chi_{}'.format(idx)] = (
- converted_parameters[mag])
-
- # catch if tidal parameters aren't present
if not any([key in converted_parameters for key in
['lambda_1', 'lambda_2', 'lambda_tilde', 'delta_lambda']]):
converted_parameters['lambda_1'] = 0
diff --git a/bilby/gw/prior.py b/bilby/gw/prior.py
index 857490e6e74c97adcbea9f42c9e8449b8aa8cf12..823977b8191d8dd74d2f1eef160c9ad1a2affe29 100644
--- a/bilby/gw/prior.py
+++ b/bilby/gw/prior.py
@@ -336,10 +336,12 @@ class BNSPriorDict(PriorDict):
By default this generates many additional parameters, see
BNSPriorDict.default_conversion_function
"""
- if not aligned_spin:
- logger.warning('Non-aligned spins not yet supported for BNS.')
+ if aligned_spin:
+ default_file = 'binary_neutron_stars.prior'
+ else:
+ default_file = 'precessing_binary_neutron_stars.prior'
if dictionary is None and filename is None:
- filename = os.path.join(os.path.dirname(__file__), 'prior_files', 'binary_neutron_stars.prior')
+ filename = os.path.join(os.path.dirname(__file__), 'prior_files', default_file)
logger.info('No prior given, using default BNS priors in {}.'.format(filename))
elif filename is not None:
if not os.path.isfile(filename):
diff --git a/bilby/gw/prior_files/precessing_binary_neutron_stars.prior b/bilby/gw/prior_files/precessing_binary_neutron_stars.prior
new file mode 100644
index 0000000000000000000000000000000000000000..8345c152460b2add9ddafc12d53cd634ae92b824
--- /dev/null
+++ b/bilby/gw/prior_files/precessing_binary_neutron_stars.prior
@@ -0,0 +1,30 @@
+# These are the default priors we use for BNS systems.
+# Note that you may wish to use more specific mass and distance parameters.
+# These commands are all known to bilby.gw.prior.
+# Lines beginning "#" are ignored.
+mass_1 = Uniform(name='mass_1', minimum=1, maximum=2, unit='$M_{\\odot}$', boundary=None)
+mass_2 = Uniform(name='mass_2', minimum=1, maximum=2, unit='$M_{\\odot}$', boundary=None)
+mass_ratio = Constraint(name='mass_ratio', minimum=0.125, maximum=1)
+# chirp_mass = Uniform(name='chirp_mass', minimum=0.87, maximum=1.74, unit='$M_{\\odot}$', boundary=None)
+# total_mass = Uniform(name='total_mass', minimum=2, maximum=4, unit='$M_{\\odot}$', boundary=None)
+# mass_ratio = Uniform(name='mass_ratio', minimum=0.5, maximum=1, boundary=None)
+# symmetric_mass_ratio = Uniform(name='symmetric_mass_ratio', minimum=0.22, maximum=0.25, boundary=None)
+a_1 = Uniform(name='a_1', minimum=0, maximum=0.05, boundary='reflective')
+a_2 = Uniform(name='a_2', minimum=0, maximum=0.05, boundary='reflective')
+tilt_1 = Sine(name='tilt_1', boundary='reflective')
+tilt_2 = Sine(name='tilt_2', boundary='reflective')
+# cos_tilt_1 = Uniform(name='cos_tilt_1', minimum=-1, maximum=1, boundary=None)
+# cos_tilt_2 = Uniform(name='cos_tilt_2', minimum=-1, maximum=1, boundary=None)
+phi_12 = Uniform(name='phi_12', minimum=0, maximum=2 * np.pi, boundary='periodic')
+phi_jl = Uniform(name='phi_jl', minimum=0, maximum=2 * np.pi, boundary='periodic')
+luminosity_distance = bilby.gw.prior.UniformSourceFrame(name='luminosity_distance', minimum=10, maximum=500, unit='Mpc', boundary=None)
+dec = Cosine(name='dec', boundary='reflective')
+ra = Uniform(name='ra', minimum=0, maximum=2 * np.pi, boundary='periodic')
+theta_jn = Sine(name='theta_jn', boundary='reflective')
+# cos_theta_jn = Uniform(name='cos_theta_jn', minimum=-1, maximum=1, boundary=None)
+psi = Uniform(name='psi', minimum=0, maximum=np.pi, boundary='periodic')
+phase = Uniform(name='phase', minimum=0, maximum=2 * np.pi, boundary='periodic')
+lambda_1 = Uniform(name='lambda_1', minimum=0, maximum=3000, boundary=None)
+lambda_2 = Uniform(name='lambda_2', minimum=0, maximum=3000, boundary=None)
+# lambda_tilde = Uniform(name='lambda_tilde', minimum=0, maximum=5000, boundary=None)
+# delta_lambda = Uniform(name='delta_lambda', minimum=-5000, maximum=5000, boundary=None)
diff --git a/bilby/gw/source.py b/bilby/gw/source.py
index 5a90b5be2f1f3243f444b29003624f7f12a8cf77..b5a3c556d8fc6719310336418d931e5c2708de2c 100644
--- a/bilby/gw/source.py
+++ b/bilby/gw/source.py
@@ -72,8 +72,9 @@ def lal_binary_black_hole(
def lal_binary_neutron_star(
- frequency_array, mass_1, mass_2, luminosity_distance, chi_1, chi_2,
- theta_jn, phase, lambda_1, lambda_2, **kwargs):
+ frequency_array, mass_1, mass_2, luminosity_distance, a_1, tilt_1,
+ phi_12, a_2, tilt_2, phi_jl, theta_jn, phase, lambda_1, lambda_2,
+ **kwargs):
""" A Binary Neutron Star waveform model using lalsimulation
Parameters
@@ -86,27 +87,27 @@ def lal_binary_neutron_star(
The mass of the lighter object in solar masses
luminosity_distance: float
The luminosity distance in megaparsec
- chi_1: float
- Dimensionless aligned spin
- chi_2: float
- Dimensionless aligned spin
+ a_1: float
+ Dimensionless primary spin magnitude
+ tilt_1: float
+ Primary tilt angle
+ phi_12: float
+ Azimuthal angle between the two component spins
+ a_2: float
+ Dimensionless secondary spin magnitude
+ tilt_2: float
+ Secondary tilt angle
+ phi_jl: float
+ Azimuthal angle between the total binary angular momentum and the
+ orbital angular momentum
theta_jn: float
Orbital inclination
phase: float
The phase at coalescence
- ra: float
- The right ascension of the binary
- dec: float
- The declination of the object
- geocent_time: float
- The time at coalescence
- psi: float
- Orbital polarisation
lambda_1: float
Dimensionless tidal deformability of mass_1
lambda_2: float
Dimensionless tidal deformability of mass_2
-
kwargs: dict
Optional keyword arguments
@@ -115,20 +116,16 @@ def lal_binary_neutron_star(
dict: A dictionary with the plus and cross polarisation strain modes
"""
waveform_kwargs = dict(
- waveform_approximant='TaylorF2', reference_frequency=50.0,
+ waveform_approximant='IMRPhenomPv2_NRTidal', reference_frequency=50.0,
minimum_frequency=20.0, maximum_frequency=frequency_array[-1],
- pn_spin_order=-1, pn_tidal_order=-1, pn_phase_order=-1, pn_amplitude_order=0)
-
- a_1 = abs(chi_1)
- a_2 = abs(chi_2)
- tilt_1 = np.arccos(np.sign(chi_1))
- tilt_2 = np.arccos(np.sign(chi_2))
+ pn_spin_order=-1, pn_tidal_order=-1, pn_phase_order=-1,
+ pn_amplitude_order=0)
waveform_kwargs.update(kwargs)
return _base_lal_cbc_fd_waveform(
frequency_array=frequency_array, mass_1=mass_1, mass_2=mass_2,
luminosity_distance=luminosity_distance, theta_jn=theta_jn, phase=phase,
- a_1=a_1, a_2=a_2, tilt_1=tilt_1, tilt_2=tilt_2, lambda_1=lambda_1,
- lambda_2=lambda_2, **waveform_kwargs)
+ a_1=a_1, a_2=a_2, tilt_1=tilt_1, tilt_2=tilt_2, phi_12=phi_12,
+ phi_jl=phi_jl, lambda_1=lambda_1, lambda_2=lambda_2, **waveform_kwargs)
def lal_eccentric_binary_black_hole_no_spins(
diff --git a/examples/injection_examples/binary_neutron_star_example.py b/examples/injection_examples/binary_neutron_star_example.py
index 81db9eda258be387229cfc31595fce1895477718..1bfe2433dc308dcbb6de17c0a0fc96f2d3c474b5 100644
--- a/examples/injection_examples/binary_neutron_star_example.py
+++ b/examples/injection_examples/binary_neutron_star_example.py
@@ -39,7 +39,7 @@ sampling_frequency = 2 * 1570.
start_time = injection_parameters['geocent_time'] + 2 - duration
# Fixed arguments passed into the source model. The analysis starts at 40 Hz.
-waveform_arguments = dict(waveform_approximant='TaylorF2',
+waveform_arguments = dict(waveform_approximant='IMRPhenomPv2_NRTidal',
reference_frequency=50., minimum_frequency=40.0)
# Create the waveform_generator using a LAL Binary Neutron Star source function
@@ -64,6 +64,8 @@ interferometers.inject_signal(parameters=injection_parameters,
# Load the default prior for binary neutron stars.
# We're going to sample in chirp_mass, symmetric_mass_ratio, lambda_tilde, and
# delta_lambda rather than mass_1, mass_2, lambda_1, and lambda_2.
+# BNS have aligned spins by default, if you want to allow precessing spins
+# pass aligned_spin=False to the BNSPriorDict
priors = bilby.gw.prior.BNSPriorDict()
for key in ['psi', 'geocent_time', 'ra', 'dec', 'chi_1', 'chi_2',
'theta_jn', 'luminosity_distance', 'phase']:
@@ -81,7 +83,7 @@ priors['delta_lambda'] = bilby.core.prior.Uniform(
-5000, 5000, name='delta_lambda')
# Initialise the likelihood by passing in the interferometer data (IFOs)
-# and the waveoform generator
+# and the waveform generator
likelihood = bilby.gw.GravitationalWaveTransient(
interferometers=interferometers, waveform_generator=waveform_generator,
time_marginalization=False, phase_marginalization=False,
diff --git a/test/conversion_test.py b/test/conversion_test.py
index 7ee6bda1d60d0572061473d00fb7bb42ffa4af67..fa6c86197bceea606b0b9184cd18c8b3f8990df5 100644
--- a/test/conversion_test.py
+++ b/test/conversion_test.py
@@ -250,13 +250,6 @@ class TestConvertToLALParams(unittest.TestCase):
def test_lambda_1(self):
self._conversion_to_component_tidal(['lambda_1'])
- def test_bns_spherical_spin_to_aligned(self):
- self.parameters['a_1'] = -1
- self.parameters['tilt_1'] = np.arccos(0.5)
- chi_1 = self.parameters['a_1'] * np.cos(self.parameters['tilt_1'])
- self.bns_convert()
- self.assertEqual(self.parameters['chi_1'], chi_1)
-
class TestDistanceTransformations(unittest.TestCase):
diff --git a/test/gw_source_test.py b/test/gw_source_test.py
index 82316e8253089b20e97bbb617829af73f61f58d1..4d098a0dd20f0c66ee245b768ebff2121306a674 100644
--- a/test/gw_source_test.py
+++ b/test/gw_source_test.py
@@ -47,11 +47,12 @@ class TestLalBNS(unittest.TestCase):
def setUp(self):
self.parameters = dict(
- mass_1=1.4, mass_2=1.4, luminosity_distance=400.0, chi_1=0.4,
- chi_2=0.3, theta_jn=1.7, phase=0.0, lambda_1=100.0, lambda_2=100.0)
+ mass_1=1.4, mass_2=1.4, luminosity_distance=400.0, a_1=0.4,
+ a_2=0.3, tilt_1=0.2, tilt_2=1.7, phi_jl=0.2, phi_12=0.9,
+ theta_jn=1.7, phase=0.0, lambda_1=100.0, lambda_2=100.0)
self.waveform_kwargs = dict(
- waveform_approximant='TaylorF2', reference_frequency=50.0,
- minimum_frequency=20.0)
+ waveform_approximant='IMRPhenomPv2_NRTidal',
+ reference_frequency=50.0, minimum_frequency=20.0)
self.frequency_array = bilby.core.utils.create_frequency_series(2048, 4)
def tearDown(self):
@@ -59,7 +60,7 @@ class TestLalBNS(unittest.TestCase):
del self.waveform_kwargs
del self.frequency_array
- def test_lal_bns_works_runs_valid_parameters(self):
+ def test_lal_bns_runs_with_valid_parameters(self):
self.parameters.update(self.waveform_kwargs)
self.assertIsInstance(
bilby.gw.source.lal_binary_neutron_star(
@@ -78,14 +79,6 @@ class TestLalBNS(unittest.TestCase):
bilby.gw.source.lal_binary_neutron_star(
self.frequency_array, **self.parameters)
- def test_fails_without_aligned_spins(self):
- self.parameters.pop('chi_1')
- self.parameters.pop('chi_2')
- self.parameters.update(self.waveform_kwargs)
- with self.assertRaises(TypeError):
- bilby.gw.source.lal_binary_neutron_star(
- self.frequency_array, **self.parameters)
-
class TestEccentricLalBBH(unittest.TestCase):