Peering through the OH Forest: public release of sky-residual subtracted spectra for SDSS DR7

Understand

The Sloan Digital Sky Survey (SDSS) automated spectroscopic reduction pipeline provides >1.5 million intermediate resolution, R~2000, moderate signal-to-noise ratio (SNR), SNR~15, astronomical spectra of unprecedented homogeneity that cover the wavelength range 3800-9200AA.

• However, there remain significant systematic residuals in many spectra due to the sub-optimal subtraction of the strong OH sky emission lines longward of 6700AA.
• The OH sky lines extend over almost half the wavelength range of the SDSS spectra, and the SNR over substantial wavelength regions in many spectra is reduced by more than a factor two over that expected from photon counting statistics.
• Following the OH line subtraction procedure presented in Wild & Hewett (2005), we make available to the community sky-residual subtracted spectra for the Sloan Digital Sky Survey Data Relase 7.