Source code for gala.potential.potential.builtin.special

# Third-party
import astropy.units as u
import numpy as np

# Project
# from .cpotential import CCompositePotential
# from ..core import CompositePotential
from .cybuiltin import (HernquistPotential,
                        MiyamotoNagaiPotential,
                        LogarithmicPotential,
                        NFWPotential,
                        PowerLawCutoffPotential)
from ..ccompositepotential import CCompositePotential
from ....units import galactic

__all__ = ['LM10Potential', 'MilkyWayPotential', 'BovyMWPotential2014']

[docs]class LM10Potential(CCompositePotential): """ The Galactic potential used by Law and Majewski (2010) to represent the Milky Way as a three-component sum of disk, bulge, and halo. The disk potential is an axisymmetric :class:`~gala.potential.MiyamotoNagaiPotential`, the bulge potential is a spherical :class:`~gala.potential.HernquistPotential`, and the halo potential is a triaxial :class:`~gala.potential.LogarithmicPotential`. Default parameters are fixed to those found in LM10 by fitting N-body simulations to the Sagittarius stream. Parameters ---------- units : `~gala.units.UnitSystem` (optional) Set of non-reducable units that specify (at minimum) the length, mass, time, and angle units. disk : dict (optional) Parameters to be passed to the :class:`~gala.potential.MiyamotoNagaiPotential`. bulge : dict (optional) Parameters to be passed to the :class:`~gala.potential.HernquistPotential`. halo : dict (optional) Parameters to be passed to the :class:`~gala.potential.LogarithmicPotential`. Note: in subclassing, order of arguments must match order of potential components added at bottom of init. """ def __init__(self, units=galactic, disk=dict(), bulge=dict(), halo=dict()): default_disk = dict(m=1E11*u.Msun, a=6.5*u.kpc, b=0.26*u.kpc) default_bulge = dict(m=3.4E10*u.Msun, c=0.7*u.kpc) default_halo = dict(q1=1.38, q2=1., q3=1.36, r_h=12.*u.kpc, phi=97*u.degree, v_c=np.sqrt(2)*121.858*u.km/u.s) for k, v in default_disk.items(): if k not in disk: disk[k] = v for k, v in default_bulge.items(): if k not in bulge: bulge[k] = v for k, v in default_halo.items(): if k not in halo: halo[k] = v super().__init__() self["disk"] = MiyamotoNagaiPotential(units=units, **disk) self["bulge"] = HernquistPotential(units=units, **bulge) self["halo"] = LogarithmicPotential(units=units, **halo) self.lock = True
[docs]class MilkyWayPotential(CCompositePotential): """ A simple mass-model for the Milky Way consisting of a spherical nucleus and bulge, a Miyamoto-Nagai disk, and a spherical NFW dark matter halo. The disk model is taken from `Bovy (2015) <https://ui.adsabs.harvard.edu/#abs/2015ApJS..216...29B/abstract>`_ - if you use this potential, please also cite that work. Default parameters are fixed by fitting to a compilation of recent mass measurements of the Milky Way, from 10 pc to ~150 pc. Parameters ---------- units : `~gala.units.UnitSystem` (optional) Set of non-reducable units that specify (at minimum) the length, mass, time, and angle units. disk : dict (optional) Parameters to be passed to the :class:`~gala.potential.MiyamotoNagaiPotential`. bulge : dict (optional) Parameters to be passed to the :class:`~gala.potential.HernquistPotential`. halo : dict (optional) Parameters to be passed to the :class:`~gala.potential.NFWPotential`. nucleus : dict (optional) Parameters to be passed to the :class:`~gala.potential.HernquistPotential`. Note: in subclassing, order of arguments must match order of potential components added at bottom of init. """ def __init__(self, units=galactic, disk=None, halo=None, bulge=None, nucleus=None): default_disk = dict(m=6.8E10*u.Msun, a=3.*u.kpc, b=0.28*u.kpc) default_bulge = dict(m=5E9*u.Msun, c=1.0*u.kpc) default_nucl = dict(m=1.71E9*u.Msun, c=0.07*u.kpc) default_halo = dict(m=5.4E11*u.Msun, r_s=15.62*u.kpc) if disk is None: disk = dict() if halo is None: halo = dict() if bulge is None: bulge = dict() if nucleus is None: nucleus = dict() for k, v in default_disk.items(): if k not in disk: disk[k] = v for k, v in default_bulge.items(): if k not in bulge: bulge[k] = v for k, v in default_halo.items(): if k not in halo: halo[k] = v for k, v in default_nucl.items(): if k not in nucleus: nucleus[k] = v super().__init__() self["disk"] = MiyamotoNagaiPotential(units=units, **disk) self["bulge"] = HernquistPotential(units=units, **bulge) self["nucleus"] = HernquistPotential(units=units, **nucleus) self["halo"] = NFWPotential(units=units, **halo) self.lock = True
[docs]class BovyMWPotential2014(CCompositePotential): """ An implementation of the ``MWPotential2014`` `from galpy <https://galpy.readthedocs.io/en/latest/potential.html>`_ and described in `Bovy (2015) <https://ui.adsabs.harvard.edu/#abs/2015ApJS..216...29B/abstract>`_. This potential consists of a spherical bulge and dark matter halo, and a Miyamoto-Nagai disk component. .. note:: Because it internally uses the PowerLawCutoffPotential, this potential requires GSL to be installed, and Gala must have been built and installed with GSL support enaled (the default behavior). See http://gala.adrian.pw/en/latest/install.html for more information. Parameters ---------- units : `~gala.units.UnitSystem` (optional) Set of non-reducable units that specify (at minimum) the length, mass, time, and angle units. disk : dict (optional) Parameters to be passed to the :class:`~gala.potential.MiyamotoNagaiPotential`. bulge : dict (optional) Parameters to be passed to the :class:`~gala.potential.PowerLawCutoffPotential`. halo : dict (optional) Parameters to be passed to the :class:`~gala.potential.NFWPotential`. Note: in subclassing, order of arguments must match order of potential components added at bottom of init. """ def __init__(self, units=galactic, disk=None, halo=None, bulge=None): default_disk = dict(m=68193902782.346756*u.Msun, a=3.*u.kpc, b=280*u.pc) default_bulge = dict(m=4501365375.06545*u.Msun, alpha=1.8, r_c=1.9*u.kpc) default_halo = dict(m=4.3683325e11*u.Msun, r_s=16*u.kpc) if disk is None: disk = dict() if halo is None: halo = dict() if bulge is None: bulge = dict() for k, v in default_disk.items(): if k not in disk: disk[k] = v for k, v in default_bulge.items(): if k not in bulge: bulge[k] = v for k, v in default_halo.items(): if k not in halo: halo[k] = v super().__init__() self["disk"] = MiyamotoNagaiPotential(units=units, **disk) self["bulge"] = PowerLawCutoffPotential(units=units, **bulge) self["halo"] = NFWPotential(units=units, **halo) self.lock = True
# -------------------------------------------------------------------- # class TriaxialMWPotential(CCompositePotential): # def __init__(self, units=galactic, # disk=dict(), bulge=dict(), halo=dict()): # """ Axis ratio values taken from Jing & Suto (2002). Other # parameters come from a by-eye fit to Bovy's MW2014Potential. # Choice of v_c sets circular velocity at Sun to 220 km/s # """ # default_disk = dict(m=7E10, a=3.5, b=0.14) # default_bulge = dict(m=1E10, c=1.1) # default_halo = dict(a=1., b=0.75, c=0.55, # v_c=0.239225, r_s=30., # phi=0., theta=0., psi=0.) # for k,v in default_disk.items(): # if k not in disk: # disk[k] = v # for k,v in default_bulge.items(): # if k not in bulge: # bulge[k] = v # for k,v in default_halo.items(): # if k not in halo: # halo[k] = v # kwargs = dict() # kwargs["disk"] = MiyamotoNagaiPotential(units=units, **disk) # kwargs["bulge"] = HernquistPotential(units=units, **bulge) # kwargs["halo"] = LeeSutoTriaxialNFWPotential(units=units, **halo) # super(TriaxialMWPotential,self).__init__(**kwargs) # --------------------------------------------------------------------