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.

property epsilon

[float, list, numpy.ndarray]

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

property 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.

property 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

property 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.

property 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).

property 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.

property 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.

property 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.

property n_masses

int, read-only

number of masses in the system.

property 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.

property 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.

property 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.

property 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