Data Reduction | Gemini Observatory

Raw data

PIs will receive raw data and reduced data in FITS format. Raw data will be made available shortly after the observations through the Gemini Observatory Archive, while reduced data will be delivered within 4 weeks after the observation by the instrument team. Raw frames will be multi-extension FITS (MEF) files containing both the blue and red 2D frame. The header will have the standard parameters as well as a snapshot of the instrument telemetry database.

Reduced 1D spectra

Data reduction is handled by a custom Python 3 data reduction pipeline. The pipeline will ultimately be incorporated into Gemini’s Dragon platform and released to the public. Until then, the PIs will continue to receive the reduced data as FITS tables at the following levels:

All spectra - Level 0:
- 1D reduced spectra from box extraction and optimal extraction routines per fiber and order
- 1D uncertainty vector per fiber and order
- 1D wavelength vector per fiber and order
Science spectra only - Level 1:
- Same as Level 0 but all three object fibers co-added and merged onto a single wavelength vector
Science spectra only - Level 2:
- All orders de-blazed and merged into a continuous spectrum, both per fiber and for all fibers combined.

Radial Velocities

PIs will be provided with RV data depending on target type and observing strategies. If sufficient observations of the target have been obtained to construct a high-SNR template, we provide RVs and auxiliary data (chromatic index, differential line width, spectral line indices for selected absorption lines) based on the SERVAL pipeline (see Zechmeister et al. 2018, A&A 609, A12).

Alternative RV analysis methods (binary template cross-correlation, Gaussian process modeling) can be applied and will be discussed with the PIs.