ZodiacalLight

class gunagala.sky.ZodiacalLight(**kwargs)

Bases: gunagala.sky.Sky

Class representing the Zodiacal Light sky background.

Includes methods that return the absolute surface brightness spectral flux density at the ecliptic poles as well as the relative brightness variations as a function of position on the sky.

Attributes:

waves : astropy.units.Quantity

Sequence of wavelengths used by the internal model

self.sfd : astropy.units.Quantity

Sequence of ecliptic pole surface brightness spectral flux density values corresponding to the wavelengths in waves, in energy flux per unit wavelength units.

self.photon_sfd : astropy.units.Quantity

Sequence of ecliptic pole surface brightness spectral flux density values corresponding to the wavelengths in waves, in photon flux per unit wavelength units.

Methods Summary

relative_brightness(position, time)	Calculate the Zodiacal Light surface brightness relative to that at the ecliptic poles for a given sky position and observing time.
surface_brightness(**kwargs)	Generates a function that will calculate Zodiacal Light ecliptic pole surface brightness as a function of wavelength, in photon spectral flux density units.

Methods Documentation

relative_brightness(position, time)

Calculate the Zodiacal Light surface brightness relative to that at the ecliptic poles for a given sky position and observing time.

At present to model includes the annual rotation of the Zodiacal Light distribution as the Earth orbits the Sun but does not include second order effects due to the inclination of the Earth’s orbit relative to the mid plane of the Zodiacal dust disc.

Parameters:

position : astropy.coordinates.SkyCoord or str

Sky position(s) in the form of either a astropy.coordinates.SkyCoord object or a string that can be converted into one.

time : astropy.time.Time or str

Time of observation in the form of either an astropy.time.Time or a string that can be converted into one.

Returns:

rel_SB : numpy.array

Relative sky brightness of the Zodiacal light at the given sky position(s)

surface_brightness(**kwargs)

Generates a function that will calculate Zodiacal Light ecliptic pole surface brightness as a function of wavelength, in photon spectral flux density units.

The returned function take a single astropy.units.Quantity parameter, the wavelength(s) at which the Zodiacal Light surface brightness is required. It returns an astropy.units.Quantity object containing the corresponding surface brightness values. See imager.Imager for a usage example.

Returns:

surface_brightness : callable

Function that calculates the ecliptic pole surface brightness for arbitrary wavelength(s).