def make_plots(all_particles, disk_only, i=0):
for j, particles in enumerate([all_particles, disk_only]):
if HAS_PYNBODY:
temp_particles = particles.copy()
temp_particles.u = 1 | units.ms**2
temp = Gadget2()
temp.gas_particles.add_particles(temp_particles)
temp.commit_particles()
pynbody_column_density_plot(
temp.gas_particles, width=300 | units.kpc, units='m_p cm^-2',
vmin=17, vmax=23)
temp.stop()
else:
native_plot.gca().set_aspect("equal")
native_plot.xlim(-150, 150)
native_plot.ylim(-150, 150)
plot(particles.x.as_quantity_in(units.kpc),
particles.y.as_quantity_in(units.kpc), 'r.')
native_plot.savefig(
os.path.join(
"plots",
"plot_galaxy_merger_{0}_{1:=04}.png".format(
"disk" if j else "total", i)
)
)
native_plot.close()
def make_plots(all_particles, disk_only, i=0):
for j, particles in enumerate([all_particles, disk_only]):
if HAS_PYNBODY:
temp_particles = particles.copy()
temp_particles.u = 1 | units.ms**2
temp = Gadget2()
temp.gas_particles.add_particles(temp_particles)
temp.commit_particles()
pynbody_column_density_plot(temp.gas_particles,
width=300 | units.kpc,
units='m_p cm^-2',
vmin=17,
vmax=23)
temp.stop()
else:
native_plot.gca().set_aspect("equal")
native_plot.xlim(-150, 150)
native_plot.ylim(-150, 150)
plot(particles.x.as_quantity_in(units.kpc),
particles.y.as_quantity_in(units.kpc), 'r.')
native_plot.savefig(
os.path.join(
"plots", "plot_galaxy_merger_{0}_{1:=04}.png".format(
"disk" if j else "total", i)))
native_plot.close()
def density_plot(coupled_system, i_step):
if not HAS_PYNBODY:
return
figname = os.path.join("plots", "hydro_giant{0:=04}.png".format(i_step))
print " - Hydroplot saved to: ", figname
pynbody_column_density_plot(coupled_system.gas_particles,
width=3 | units.AU,
vmin=26,
vmax=33)
scatter(coupled_system.dm_particles.x,
coupled_system.dm_particles.y,
c="w")
pyplot.savefig(figname)
pyplot.close()
def slowtest1(self):
stellar_evolution = self.new_instance(MESA)
stellar_evolution.particles.add_particles(Particles(2, mass=[1.0, 5.0]|units.MSun))
stellar_evolution.evolve_model(10.0 | units.Myr)
initial_separation = stellar_evolution.particles.radius.sum()
sph_particles_1 = convert_stellar_model_to_SPH(
stellar_evolution.particles[0],
200,
seed=12345
).gas_particles
sph_particles_2 = convert_stellar_model_to_SPH(
stellar_evolution.particles[1],
1000,
seed=12345
).gas_particles
stellar_evolution.stop()
initial_speed = 10.0 | units.km / units.s
sph_particles_2.x += initial_separation
sph_particles_1.vx += initial_speed
all_sph_particles = ParticlesSuperset([sph_particles_1, sph_particles_2])
all_sph_particles.move_to_center()
t_end = 4.0e3 | units.s
print "Evolving to:", t_end
n_steps = 4
unit_system_converter = ConvertBetweenGenericAndSiUnits(1.0 | units.RSun, 1.0 | units.MSun, t_end)
hydro_code = Gadget2(unit_system_converter)
hydro_code.gas_particles.add_particles(all_sph_particles)
pyplot.ion()
for time in [i*t_end/n_steps for i in range(1, n_steps+1)]:
hydro_code.evolve_model(time)
pyplot.close('all')
pyplot.figure()
pynbody_column_density_plot(hydro_code.gas_particles, width=10|units.RSun)
pyplot.draw()
pyplot.figure()
loglog(hydro_code.gas_particles.position.lengths_squared(), hydro_code.gas_particles.pressure, 'bo')
pyplot.draw()
hydro_code.stop()
sleep(3)
pyplot.ioff()
def slowtest1(self):
stellar_evolution = self.new_instance(MESA)
stellar_evolution.particles.add_particles(
Particles(2, mass=[1.0, 5.0] | units.MSun))
stellar_evolution.evolve_model(10.0 | units.Myr)
initial_separation = stellar_evolution.particles.radius.sum()
sph_particles_1 = convert_stellar_model_to_SPH(
stellar_evolution.particles[0], 200, seed=12345).gas_particles
sph_particles_2 = convert_stellar_model_to_SPH(
stellar_evolution.particles[1], 1000, seed=12345).gas_particles
stellar_evolution.stop()
initial_speed = 10.0 | units.km / units.s
sph_particles_2.x += initial_separation
sph_particles_1.vx += initial_speed
all_sph_particles = ParticlesSuperset(
[sph_particles_1, sph_particles_2])
all_sph_particles.move_to_center()
t_end = 4.0e3 | units.s
print "Evolving to:", t_end
n_steps = 4
unit_system_converter = ConvertBetweenGenericAndSiUnits(
1.0 | units.RSun, 1.0 | units.MSun, t_end)
hydro_code = Gadget2(unit_system_converter)
hydro_code.gas_particles.add_particles(all_sph_particles)
pyplot.ion()
for time in [i * t_end / n_steps for i in range(1, n_steps + 1)]:
hydro_code.evolve_model(time)
pyplot.close('all')
pyplot.figure()
pynbody_column_density_plot(hydro_code.gas_particles,
width=10 | units.RSun)
pyplot.draw()
pyplot.figure()
loglog(hydro_code.gas_particles.position.lengths_squared(),
hydro_code.gas_particles.pressure, 'bo')
pyplot.draw()
hydro_code.stop()
sleep(3)
pyplot.ioff()
def evolve_system(system, t_end, n_steps):
times = (t_end * range(1, n_steps+1) / n_steps).as_quantity_in(units.day)
for i_step, time in enumerate(times):
system.evolve_model(time)
print " Evolved to:", time,
figname = os.path.join("plots", "hydro_giant_{0:=04}.png".format(i_step))
print " - Hydroplot saved to: ", figname
pynbody_column_density_plot(system.gas_particles, width=30|units.AU, vmin=26, vmax=33)
scatter(system.dm_particles.x, system.dm_particles.y, c="w")
pyplot.savefig(figname)
pyplot.close()
file_base_name = os.path.join("snapshots", "hydro_giant_{0:=04}_".format(i_step))
write_set_to_file(system.gas_particles, file_base_name+"gas.amuse", format='amuse')
write_set_to_file(system.dm_particles, file_base_name+"dm.amuse", format='amuse')
system.stop()
def evolve_coupled_system(binary_system, giant_system, t_end, n_steps,
do_energy_evolution_plot, previous_data=None):
directsum = CalculateFieldForParticles(particles=giant_system.particles, gravity_constant=constants.G)
directsum.smoothing_length_squared = giant_system.parameters.gas_epsilon**2
coupled_system = Bridge(timestep=(t_end / (2 * n_steps)), verbose=False, use_threading=True)
coupled_system.add_system(binary_system, (directsum,), False)
coupled_system.add_system(giant_system, (binary_system,), False)
times = (t_end * list(range(1, n_steps+1)) / n_steps).as_quantity_in(units.day)
if previous_data:
with open(previous_data, 'rb') as file:
(all_times, potential_energies, kinetic_energies, thermal_energies,
giant_center_of_mass, ms1_position, ms2_position,
giant_center_of_mass_velocity, ms1_velocity, ms2_velocity) = pickle.load(file)
all_times.extend(times + all_times[-1])
else:
all_times = times
if do_energy_evolution_plot:
potential_energies = coupled_system.particles.potential_energy().as_vector_with_length(1).as_quantity_in(units.erg)
kinetic_energies = coupled_system.particles.kinetic_energy().as_vector_with_length(1).as_quantity_in(units.erg)
thermal_energies = coupled_system.gas_particles.thermal_energy().as_vector_with_length(1).as_quantity_in(units.erg)
else:
potential_energies = kinetic_energies = thermal_energies = None
giant_center_of_mass = [] | units.RSun
ms1_position = [] | units.RSun
ms2_position = [] | units.RSun
giant_center_of_mass_velocity = [] | units.km / units.s
ms1_velocity = [] | units.km / units.s
ms2_velocity = [] | units.km / units.s
i_offset = len(giant_center_of_mass)
giant_total_mass = giant_system.particles.total_mass()
ms1_mass = binary_system.particles[0].mass
ms2_mass = binary_system.particles[1].mass
print(" Evolving for", t_end)
for i_step, time in enumerate(times):
coupled_system.evolve_model(time)
print(" Evolved to:", time, end=' ')
if do_energy_evolution_plot:
potential_energies.append(coupled_system.particles.potential_energy())
kinetic_energies.append(coupled_system.particles.kinetic_energy())
thermal_energies.append(coupled_system.gas_particles.thermal_energy())
giant_center_of_mass.append(giant_system.particles.center_of_mass())
ms1_position.append(binary_system.particles[0].position)
ms2_position.append(binary_system.particles[1].position)
giant_center_of_mass_velocity.append(giant_system.particles.center_of_mass_velocity())
ms1_velocity.append(binary_system.particles[0].velocity)
ms2_velocity.append(binary_system.particles[1].velocity)
a_giant, e_giant = calculate_orbital_elements(ms1_mass, ms2_mass,
ms1_position, ms2_position,
ms1_velocity, ms2_velocity,
giant_total_mass,
giant_center_of_mass,
giant_center_of_mass_velocity)
print("Outer Orbit:", time.in_(units.day), a_giant[-1].in_(units.AU), e_giant[-1], ms1_mass.in_(units.MSun), ms2_mass.in_(units.MSun), giant_total_mass.in_(units.MSun))
if i_step % 10 == 9:
snapshotfile = os.path.join("snapshots", "hydro_triple_{0:=04}_gas.amuse".format(i_step + i_offset))
write_set_to_file(giant_system.gas_particles, snapshotfile, format='amuse')
snapshotfile = os.path.join("snapshots", "hydro_triple_{0:=04}_core.amuse".format(i_step + i_offset))
write_set_to_file(giant_system.dm_particles, snapshotfile, format='amuse')
snapshotfile = os.path.join("snapshots", "hydro_triple_{0:=04}_binary.amuse".format(i_step + i_offset))
write_set_to_file(binary_system.particles, snapshotfile, format='amuse')
datafile = os.path.join("snapshots", "hydro_triple_{0:=04}_info.amuse".format(i_step + i_offset))
with open(datafile, 'wb') as outfile:
pickle.dump((all_times[:len(giant_center_of_mass)], potential_energies,
kinetic_energies, thermal_energies, giant_center_of_mass,
ms1_position, ms2_position, giant_center_of_mass_velocity,
ms1_velocity, ms2_velocity), outfile)
figname1 = os.path.join("plots", "hydro_triple_small{0:=04}.png".format(i_step + i_offset))
figname2 = os.path.join("plots", "hydro_triple_large{0:=04}.png".format(i_step + i_offset))
print(" - Hydroplots are saved to: ", figname1, "and", figname2)
for plot_range, plot_name in [(8|units.AU, figname1), (40|units.AU, figname2)]:
if HAS_PYNBODY:
pynbody_column_density_plot(coupled_system.gas_particles, width=plot_range, vmin=26, vmax=32)
scatter(coupled_system.dm_particles.x, coupled_system.dm_particles.y, c="w")
else:
pyplot.figure(figsize = [16, 16])
sph_particles_plot(coupled_system.gas_particles, gd_particles=coupled_system.dm_particles,
view=plot_range*[-0.5, 0.5, -0.5, 0.5])
pyplot.savefig(plot_name)
pyplot.close()
coupled_system.stop()
make_movie()
if do_energy_evolution_plot:
energy_evolution_plot(all_times[:len(kinetic_energies)-1], kinetic_energies,
potential_energies, thermal_energies)
print(" Calculating semimajor axis and eccentricity evolution for inner binary")
# Some temporary variables to calculate semimajor_axis and eccentricity evolution
total_mass = ms1_mass + ms2_mass
rel_position = ms1_position - ms2_position
rel_velocity = ms1_velocity - ms2_velocity
separation_in = rel_position.lengths()
speed_squared_in = rel_velocity.lengths_squared()
# Now calculate the important quantities:
semimajor_axis_binary = (constants.G * total_mass * separation_in /
(2 * constants.G * total_mass - separation_in * speed_squared_in)).as_quantity_in(units.AU)
eccentricity_binary = numpy.sqrt(1.0 - (rel_position.cross(rel_velocity)**2).sum(axis=1) /
(constants.G * total_mass * semimajor_axis_binary))
print(" Calculating semimajor axis and eccentricity evolution of the giant's orbit")
# Some temporary variables to calculate semimajor_axis and eccentricity evolution
rel_position = ((ms1_mass * ms1_position + ms2_mass * ms2_position)/total_mass -
giant_center_of_mass)
rel_velocity = ((ms1_mass * ms1_velocity + ms2_mass * ms2_velocity)/total_mass -
giant_center_of_mass_velocity)
total_mass += giant_total_mass
separation = rel_position.lengths()
speed_squared = rel_velocity.lengths_squared()
# Now calculate the important quantities:
semimajor_axis_giant = (constants.G * total_mass * separation /
(2 * constants.G * total_mass - separation * speed_squared)).as_quantity_in(units.AU)
eccentricity_giant = numpy.sqrt(1.0 - (rel_position.cross(rel_velocity)**2).sum(axis=1) /
(constants.G * total_mass * semimajor_axis_giant))
orbit_parameters_plot(semimajor_axis_binary, semimajor_axis_giant, all_times[:len(semimajor_axis_binary)])
orbit_ecc_plot(eccentricity_binary, eccentricity_giant, all_times[:len(eccentricity_binary)])
orbit_parameters_plot(separation_in.as_quantity_in(units.AU),
separation.as_quantity_in(units.AU),
all_times[:len(eccentricity_binary)],
par_symbol="r", par_name="separation")
orbit_parameters_plot(speed_squared_in.as_quantity_in(units.km**2 / units.s**2),
speed_squared.as_quantity_in(units.km**2 / units.s**2),
all_times[:len(eccentricity_binary)],
par_symbol="v^2", par_name="speed_squared")
def evolve_coupled_system(binary_system, giant_system, t_end, n_steps,
do_energy_evolution_plot, previous_data=None):
directsum = CalculateFieldForParticles(particles=giant_system.particles, gravity_constant=constants.G)
directsum.smoothing_length_squared = giant_system.parameters.gas_epsilon**2
coupled_system = Bridge(timestep=(t_end / (2 * n_steps)), verbose=False, use_threading=True)
coupled_system.add_system(binary_system, (directsum,), False)
coupled_system.add_system(giant_system, (binary_system,), False)
times = (t_end * range(1, n_steps+1) / n_steps).as_quantity_in(units.day)
if previous_data:
with open(previous_data, 'rb') as file:
(all_times, potential_energies, kinetic_energies, thermal_energies,
giant_center_of_mass, ms1_position, ms2_position,
giant_center_of_mass_velocity, ms1_velocity, ms2_velocity) = pickle.load(file)
all_times.extend(times + all_times[-1])
else:
all_times = times
if do_energy_evolution_plot:
potential_energies = coupled_system.particles.potential_energy().as_vector_with_length(1).as_quantity_in(units.erg)
kinetic_energies = coupled_system.particles.kinetic_energy().as_vector_with_length(1).as_quantity_in(units.erg)
thermal_energies = coupled_system.gas_particles.thermal_energy().as_vector_with_length(1).as_quantity_in(units.erg)
else:
potential_energies = kinetic_energies = thermal_energies = None
giant_center_of_mass = [] | units.RSun
ms1_position = [] | units.RSun
ms2_position = [] | units.RSun
giant_center_of_mass_velocity = [] | units.km / units.s
ms1_velocity = [] | units.km / units.s
ms2_velocity = [] | units.km / units.s
i_offset = len(giant_center_of_mass)
giant_total_mass = giant_system.particles.total_mass()
ms1_mass = binary_system.particles[0].mass
ms2_mass = binary_system.particles[1].mass
print " Evolving for", t_end
for i_step, time in enumerate(times):
coupled_system.evolve_model(time)
print " Evolved to:", time,
if do_energy_evolution_plot:
potential_energies.append(coupled_system.particles.potential_energy())
kinetic_energies.append(coupled_system.particles.kinetic_energy())
thermal_energies.append(coupled_system.gas_particles.thermal_energy())
giant_center_of_mass.append(giant_system.particles.center_of_mass())
ms1_position.append(binary_system.particles[0].position)
ms2_position.append(binary_system.particles[1].position)
giant_center_of_mass_velocity.append(giant_system.particles.center_of_mass_velocity())
ms1_velocity.append(binary_system.particles[0].velocity)
ms2_velocity.append(binary_system.particles[1].velocity)
a_giant, e_giant = calculate_orbital_elements(ms1_mass, ms2_mass,
ms1_position, ms2_position,
ms1_velocity, ms2_velocity,
giant_total_mass,
giant_center_of_mass,
giant_center_of_mass_velocity)
print "Outer Orbit:", time.in_(units.day), a_giant[-1].in_(units.AU), e_giant[-1], ms1_mass.in_(units.MSun), ms2_mass.in_(units.MSun), giant_total_mass.in_(units.MSun)
if i_step % 10 == 9:
snapshotfile = os.path.join("snapshots", "hydro_triple_{0:=04}_gas.amuse".format(i_step + i_offset))
write_set_to_file(giant_system.gas_particles, snapshotfile, format='amuse')
snapshotfile = os.path.join("snapshots", "hydro_triple_{0:=04}_core.amuse".format(i_step + i_offset))
write_set_to_file(giant_system.dm_particles, snapshotfile, format='amuse')
snapshotfile = os.path.join("snapshots", "hydro_triple_{0:=04}_binary.amuse".format(i_step + i_offset))
write_set_to_file(binary_system.particles, snapshotfile, format='amuse')
datafile = os.path.join("snapshots", "hydro_triple_{0:=04}_info.amuse".format(i_step + i_offset))
with open(datafile, 'wb') as outfile:
pickle.dump((all_times[:len(giant_center_of_mass)], potential_energies,
kinetic_energies, thermal_energies, giant_center_of_mass,
ms1_position, ms2_position, giant_center_of_mass_velocity,
ms1_velocity, ms2_velocity), outfile)
figname1 = os.path.join("plots", "hydro_triple_small{0:=04}.png".format(i_step + i_offset))
figname2 = os.path.join("plots", "hydro_triple_large{0:=04}.png".format(i_step + i_offset))
print " - Hydroplots are saved to: ", figname1, "and", figname2
for plot_range, plot_name in [(8|units.AU, figname1), (40|units.AU, figname2)]:
if HAS_PYNBODY:
pynbody_column_density_plot(coupled_system.gas_particles, width=plot_range, vmin=26, vmax=32)
scatter(coupled_system.dm_particles.x, coupled_system.dm_particles.y, c="w")
else:
pyplot.figure(figsize = [16, 16])
sph_particles_plot(coupled_system.gas_particles, gd_particles=coupled_system.dm_particles,
view=plot_range*[-0.5, 0.5, -0.5, 0.5])
pyplot.savefig(plot_name)
pyplot.close()
coupled_system.stop()
make_movie()
if do_energy_evolution_plot:
energy_evolution_plot(all_times[:len(kinetic_energies)-1], kinetic_energies,
potential_energies, thermal_energies)
print " Calculating semimajor axis and eccentricity evolution for inner binary"
# Some temporary variables to calculate semimajor_axis and eccentricity evolution
total_mass = ms1_mass + ms2_mass
rel_position = ms1_position - ms2_position
rel_velocity = ms1_velocity - ms2_velocity
separation_in = rel_position.lengths()
speed_squared_in = rel_velocity.lengths_squared()
# Now calculate the important quantities:
semimajor_axis_binary = (constants.G * total_mass * separation_in /
(2 * constants.G * total_mass - separation_in * speed_squared_in)).as_quantity_in(units.AU)
eccentricity_binary = numpy.sqrt(1.0 - (rel_position.cross(rel_velocity)**2).sum(axis=1) /
(constants.G * total_mass * semimajor_axis_binary))
print " Calculating semimajor axis and eccentricity evolution of the giant's orbit"
# Some temporary variables to calculate semimajor_axis and eccentricity evolution
rel_position = ((ms1_mass * ms1_position + ms2_mass * ms2_position)/total_mass -
giant_center_of_mass)
rel_velocity = ((ms1_mass * ms1_velocity + ms2_mass * ms2_velocity)/total_mass -
giant_center_of_mass_velocity)
total_mass += giant_total_mass
separation = rel_position.lengths()
speed_squared = rel_velocity.lengths_squared()
# Now calculate the important quantities:
semimajor_axis_giant = (constants.G * total_mass * separation /
(2 * constants.G * total_mass - separation * speed_squared)).as_quantity_in(units.AU)
eccentricity_giant = numpy.sqrt(1.0 - (rel_position.cross(rel_velocity)**2).sum(axis=1) /
(constants.G * total_mass * semimajor_axis_giant))
orbit_parameters_plot(semimajor_axis_binary, semimajor_axis_giant, all_times[:len(semimajor_axis_binary)])
orbit_ecc_plot(eccentricity_binary, eccentricity_giant, all_times[:len(eccentricity_binary)])
orbit_parameters_plot(separation_in.as_quantity_in(units.AU),
separation.as_quantity_in(units.AU),
all_times[:len(eccentricity_binary)],
par_symbol="r", par_name="separation")
orbit_parameters_plot(speed_squared_in.as_quantity_in(units.km**2 / units.s**2),
speed_squared.as_quantity_in(units.km**2 / units.s**2),
all_times[:len(eccentricity_binary)],
par_symbol="v^2", par_name="speed_squared")
