Using machine learning to classify the diffuse interstellar bands

Using over a million and a half extragalactic spectra from the Sloan Digital Sky Survey we study the correlations of the diffuse interstellar bands (DIBs) in the Milky Way. We measure the correlation between DIB strength and dust extinction for 142 DIBs using 24 stacked spectra in the reddening range E(B − V) < 0.2, many more lines than ever studied before. Most of the DIBs do not correlate with d...