Zodiacal Light Removal

Zodiacal Light Model Over Time

A video showing the model of UCSD's zodiacal subtraction map over time. The coordinate system is RA vs declination, and the intensity is the instrument's ADUs. The Sun is seen here to move along the ecliptic (a sinusoidal path), accompanied by the Gegenschein displaced 180° along the path.

The zodiacal light contributes significantly to the sky background. However, this signal varies smoothly with solar elongation and position angle, and slowly with time, so that it can be separated from the transient solar heliospheric components. We remove this signal to first order by subtracting a simple Sun-centered model that approximates the angular shape of the brightness. In order to optimize the accuracy of the photometric SMEI sky maps providing input to the 3D tomographic analyses, a temporal residue of this signal is removed by a high-pass filter.

Zodiacal Subtraction Map

Missing Image: Zodical Sub. Map

The map used for zodiacal background light removal.