AstroIC.jl

Initial condition generator for astrophysical simulations

Installation

]add AstroIC

or

using Pkg; Pkg.add("AstroIC")

or directly from git:

using Pkg; Pkg.add("https://github.com/JuliaAstroSim/AstroIC.jl")

To test the package:

]test AstroIC

Documentation

• Dev — documentation of the in-development version.

For beginners, it is highly recommended to read the documentation of PhysicalParticles.jl.

What's included

Initial condition configurations

Config type	Model
PlummerStarCluster	Plummer (1911) spherical cluster
ExponentialDisc	Exponential disk with optional central hole
Bulge	Sersic-like bulge with axis ratio q and power-law α
GasCloud	Cartesian grid SPH gas cloud
SphericalSystem	Generic spherical system from a discrete/analytic mass shell

Particle manipulation tools

setpos / setvel shift a particle system to a target position / velocity, addpos / addvel translate by a fixed offset.

Real-world data loaders

Pre-bundled CSV / DAT tables from the literature:

• Milky Way satellites (Battaglia+ 2022)
• Ultra-faint dwarf galaxies
• SPARC late- and early-type galaxy rotation curves
• Milky Way rotation curves (Eilers 2019, Mróz 2019, Wang 2021)
• Massive dwarf rotation curves (Cooke 2022)

Usage

Plummer star cluster

using AstroIC
using PhysicalParticles, UnitfulAstro

# Keyword-only constructor; defaults to 1000 particles, 0.01 kpc virial radius,
# 1e5 Msun, Newtonian gravity, uAstro units.
config = PlummerStarCluster(
    collection   = STAR,
    NumSamples   = 100,
    VirialRadius = 0.010u"kpc",
    TotalMass    = 1.0e5u"Msun",
    model        = AstroSimBase.Newton(),
)

# MaxRadius restricts the sampling region (warns if smaller than VirialRadius).
particles = generate(config; MaxRadius = 0.1u"kpc")

# Pass `uSI` to get SI units instead of the default uAstro.
particles_si = generate(config, uSI)

Exponential disk (with optional central hole)

config = ExponentialDisc(
    collection   = STAR,
    NumSamples   = 10_000,
    TotalMass    = 1.0e10u"Msun",
    ScaleRadius  = 2.0u"kpc",
    ScaleHeight  = 0.02u"kpc",
    HoleRadius   = 0.0u"kpc",   # set > 0 for a central hole
)

particles = generate(config)

Pass a RotationCurve = (radii, velocities) pair to assign realistic rotational velocities instead of zero.

Bulge

config = Bulge(
    collection  = STAR,
    NumSamples  = 5_000,
    TotalMass   = 8.57u"Msun",
    ScaleRadius = 0.075u"kpc",
    CutRadius   = 2.1u"kpc",
    q           = 0.5,
    α           = 1.8,
)

particles = generate(config)

Spherical system from a mass shell

using DataFrames

# Either an analytic shell-mass function:
shell_mass_func = x -> 1.0e8u"Msun/kpc^3" / (x / (2.0u"kpc")) /
                              (1 + x / (2.0u"kpc"))^2 * 4π * x^2

config = SphericalSystem(STAR, 1000, shell_mass_func)
particles = generate(config; MaxRadius = 6.0u"kpc")

Or a discrete (r, m) table as a Dict or DataFrame with columns :r / :m.

Gas cloud (SPH)

config = GasCloud(
    collection   = GAS,
    Radius       = 20u"kpc",
    rho0         = 1250u"Msun/kpc^3",
    T            = 300u"K",
    ParticleMass = Constant().m_p,
    Nx           = 11, Ny = 11, Nz = 11,
)

particles = generate(config)  # default uAstro

Solar system

using Dates
using AstroIC

particles = solarsystem(now())  # SI units; returns 8 planets + the Sun

Setting system center & velocity

data = generate(PlummerStarCluster(NumSamples = 100))

# Shift the system so its median position equals the given point.
setpos(data, PVector(100.0, 100.0, 100.0, u"kpc"))

# Set mass-weighted mean velocity.
setvel(data, PVector(100.0, 100.0, 100.0, u"kpc/Gyr"))

Loading real-world data

# Milky Way satellites (Battaglia+ 2022): 61 entries
df = load_data_MW_satellites()

# SPARC late-type galaxy rotation curves (Lelli+ 2016)
df = load_SPARC_LTGs_data()
rc = load_SPARC_LTGs_RC()

# Milky Way rotation curves from three independent measurements
df_eilers = load_MW_RC_Eilers2019()
df_mroz   = load_MW_RC_Mroz2019()
df_w21    = load_MW_RC_DS_W21()

Package ecosystem

• Basic data structure: PhysicalParticles.jl
• File I/O: AstroIO.jl
• Initial Condition: AstroIC.jl
• Parallelism: ParallelOperations.jl
• Trees: PhysicalTrees.jl
• Meshes: PhysicalMeshes.jl
• Plotting: AstroPlot.jl
• AstroNbodySim.jl — gravitational N-body simulations, glue layer, and parallel runtime
• Simulation of wave dark matter: WaveDM.jl