use astropy's convolution

[martinberoiz]

astropy.convolution provides convolution functions and kernels that offers improvements compared to the scipy scipy.ndimage convolution routines, including:

• Proper treatment of NaN values (ignoring them during convolution and replacing NaN pixels with interpolated values)
• A single function for 1-D, 2-D, and 3-D convolution
• Improved options for the treatment of edges
• Both direct and Fast Fourier Transform (FFT) versions
• Built-in kernels that are commonly used in Astronomy

Docs here.