MulensModel.mulensobjects.lens module

class MulensModel.mulensobjects.lens.Lens(total_mass=None, mass=None, mass_1=None, mass_2=None, a_proj=None, distance=None, q=None, s=None, epsilon=None)

Bases: object

A mass or system of masses.

Standard parameter combinations for defining a Lens object:

Point Lens:

(mass, distance)

2+ body lens:

(s, q)

(epsilon, s)

(total_mass, epsilon, distance) - Missing s/Not Implemented?

(mass_1, mass_2, a_proj, distance) - Not Implemented

Note that s, q, and epsilon may be single values, lists, or numpy ndarrays.

If units are not specified for a given mass, it is assumed the value given is in Solar Masses.

If units are not specified for distance it is assumed the value is given in kpc.

epsilon

[float, list, numpy.ndarray]

An array of mass fractions for each lens components: m_i/total_mass. Stored as a numpy.ndarray.

q

[float, list, numpy.ndarray]

mass ratio for companions relative to the primary

Array of mass ratios defined relative to the primary (m_i/m_1). Size is number of components -1. Set as a list, np.ndarray, or single value.

Note: if total_mass is defined before q, it is assumed this is the mass of the primary. If you want this to actually be the total mass, define it after defining q.

s

[float, list, numpy.ndarray]

Separation between the components of the lens as a fraction of the Einstein ring. A np.ndarray or single value.

Definitions for more than 2 lens bodies TBD

total_mass

astropy.Quantity

The total mass of the lens (sum of all components). An astropy.Quantity with mass units. If set as a float, units are assumed to be solMass.

mass

astropy.Quantity

The mass of a point lens –> total mass. An astropy.Quantity with mass units. May be set as a float (in which case solMass is assumed).

mass_1

astropy.Quantity

The mass of the primary. Defined as total_mass * epsilon[0]. An astropy.Quantity with mass units. If set as a float, units are assumed to be solMass.

mass_2

astropy.Quantity

The mass of the secondary. Defined as total_mass * epsilon[1]. An astropy.Quantity with mass units. If set as a float, units are assumed to be solMass.

Note that if total_mass is defined before mass_2, and there is no epsilon corresponding to mass_2, mass_2 is added to the total_mass.

mass_3

astropy.Quantity

The mass of the tertiary. Defined as total_mass * epsilon[2]. An astropy.Quantity with mass units. If set as a float, units are assumed to be solMass.

Note that if total_mass is defined before mass_3, and there is no epsilon corresponding to mass_3, mass_3 is added to the total_mass.

n_masses

int, read-only

number of masses in the system.

distance

astropy.Quantity

The distance to the lens.

May be set as a float. If no unit is given, the value is assumed to be kpc.

pi_L

astropy.Quantity

The parallax to the lens in milliarcseconds. May be set as a float, in which case units are assumed to be milliarcseconds.

a_proj

astropy.Quantity

Projected separation between the components of the lens in AU. An astropy.Quantity with distance units. If set as float (without units), AU is assumed.

caustics

A Caustics object, read-only

plot_caustics(n_points=5000, **kwargs)

A function to plot the x,y coordinates (scaled to the Einstein ring) of the caustics. Pyplot scatter is used for plotting. See MulensModel.caustics.Caustics.plot().

Parameters :

n_points: int

Number of points be plotted.

**kwargs:

Keyword arguments passed to Pyplot scatter