def create_stars_without_wind_attributes(self):
stars = Particles(2)
stars.mass = 2 | units.MSun
stars.radius = 2 | units.RSun
stars.temperature = 5000 | units.K
stars.luminosity = 2 | units.LSun
stars.age = 0 | units.Myr
stars[0].position = [1, 1, 1] | units.parsec
stars[1].position = [-1, -1, -1] | units.parsec
stars[0].velocity = [-1000, 0, 1000] | units.ms
stars[1].velocity = [0, 0, 0] | units.ms
return stars
def create_stars_without_wind_attributes(self):
stars = Particles(2)
stars.mass = 2 | units.MSun
stars.radius = 2 | units.RSun
stars.temperature = 5000 | units.K
stars.luminosity = 2 | units.LSun
stars.age = 0 | units.Myr
stars[0].position = [1, 1, 1] | units.parsec
stars[1].position = [-1, -1, -1] | units.parsec
stars[0].velocity = [-1000, 0, 1000] | units.ms
stars[1].velocity = [0, 0, 0] | units.ms
return stars
def new_stars_from_sink(origin,
upper_mass_limit=125 | units.MSun,
lower_mass_limit=0.1 | units.MSun,
default_radius=0.25 | units.pc,
velocity_dispersion=1 | units.kms,
logger=None,
initial_mass_function="kroupa",
distribution="random",
randomseed=None,
**keyword_arguments):
"""
Form stars from an origin particle that keeps track of the properties of
this region.
"""
logger = logger or logging.getLogger(__name__)
if randomseed is not None:
logger.info("setting random seed to %i", randomseed)
numpy.random.seed(randomseed)
try:
initialised = origin.initialised
except AttributeError:
initialised = False
if not initialised:
logger.debug("Initialising origin particle %i for star formation",
origin.key)
next_mass = new_star_cluster(
initial_mass_function=initial_mass_function,
upper_mass_limit=upper_mass_limit,
lower_mass_limit=lower_mass_limit,
number_of_stars=1,
**keyword_arguments)
origin.next_primary_mass = next_mass[0].mass
origin.initialised = True
if origin.mass < origin.next_primary_mass:
logger.debug(
"Not enough in star forming region %i to form the next star",
origin.key)
return Particles()
mass_reservoir = origin.mass - origin.next_primary_mass
stellar_masses = new_star_cluster(
stellar_mass=mass_reservoir,
upper_mass_limit=upper_mass_limit,
lower_mass_limit=lower_mass_limit,
imf=initial_mass_function,
).mass
number_of_stars = len(stellar_masses)
new_stars = Particles(number_of_stars)
new_stars.age = 0 | units.yr
new_stars[0].mass = origin.next_primary_mass
new_stars[1:].mass = stellar_masses[:-1]
origin.next_primary_mass = stellar_masses[-1]
new_stars.position = origin.position
new_stars.velocity = origin.velocity
try:
radius = origin.radius
except AttributeError:
radius = default_radius
rho = numpy.random.random(number_of_stars) * radius
theta = (numpy.random.random(number_of_stars) * (2 * numpy.pi | units.rad))
phi = (numpy.random.random(number_of_stars) * numpy.pi | units.rad)
x = rho * sin(phi) * cos(theta)
y = rho * sin(phi) * sin(theta)
z = rho * cos(phi)
new_stars.x += x
new_stars.y += y
new_stars.z += z
velocity_magnitude = numpy.random.normal(
scale=velocity_dispersion.value_in(units.kms),
size=number_of_stars,
) | units.kms
velocity_theta = (numpy.random.random(number_of_stars) *
(2 * numpy.pi | units.rad))
velocity_phi = (numpy.random.random(number_of_stars) *
(numpy.pi | units.rad))
vx = velocity_magnitude * sin(velocity_phi) * cos(velocity_theta)
vy = velocity_magnitude * sin(velocity_phi) * sin(velocity_theta)
vz = velocity_magnitude * cos(velocity_phi)
new_stars.vx += vx
new_stars.vy += vy
new_stars.vz += vz
new_stars.origin = origin.key
origin.mass -= new_stars.total_mass()
return new_stars
