Characterizing Sky Spectra from SDSS BOSS Data Lina Florez Mentor: Michael Strauss Characterizing Sky Spectra from SDSS BOSS Data

Sky Spectra These emission lines are caused by OH molecules in our atmosphere transitioning from upper levels to lower levels The figure is a sky spectrum produced by one optical fiber from the SDSS BOSS survey An issue that all ground-based telescopes must face is our atmosphere. In the data produced by any given ground-based telescope, the strength of the emission lines produced by our atmosphere are many factors larger than our actual source data. On this first figure, we have a sky spectrum plotted from a sky fiber taken from the Sloan Digital Sky Survey’s Baryonic Oscillation Spectroscopic Survey, or the SDSS BOSS Survey. Our upper atmosphere consists mainly of OH (hydroxide) and O2 (oxygen) molecules. The emission lines that you see here are created from these molecules, mainly OH, transitioning from upper levels to lower levels. This broadly is vibrational-rotational spectroscopy, which I’ll cover a bit more in depth on a later slide.

Sky Subtraction The strength of the emission lines created by our atmosphere are many factors larger than the source data As a size reference, this is a spectrum produced by a source, before the sky spectrum has been subtracted So this figure on the right

These emission lines are caused by OH molecules in our atmosphere transitioning from upper levels to lower levels The figure is a sky spectrum produced by one optical fiber from the SDSS BOSS survey

Prime Focus Spectrograph A multi-object spectrograph on the 8.2-meter Subaru Telescope The spectral resolution of PFS is about 3Å Imaging as deep as a magnitude of ~ 27

Literature On the left is one of Osterbrock et. al’s plots, detailing specific transition information for each major peak in any given sky spectrum

SDSS BOSS Data This plot is comparing the strength of two emission lines throughout one plate.

SDSS BOSS Data This right plot is comparing the strength of two emission lines throughout one plate, after the data was normalized and a 3-sigma cut was made.

SDSS BOSS Data This data is comparing two wavelengths throughout one plate. The This plot is comparing the strength of two sky lines throughout five plates. 

SDSS BOSS Data This right plot is comparing the strength of two emission lines throughout five plates, after the data was normalized and a 3-sigma cut was made. 

Conclusion I’ll continue to do line comparisons throughout more plates and using different pairs of lines Eventually go ahead and do Principal Component Analysis on the data to attempt to find more correlations

Special Thanks Michael Strauss Jonah Donnenfield The USRP/NAC program