Calibrations |
Darks and bad pixels | from images of the non-illuminated spectrograph, the pipeline generates a master dark 2D image and a bad-pixel map |
Order localization | from flatfield images, the pipeline identifies the precise position of all 49 orders and stores it into "loco" files |
Blaze function | from flatfield images, the pipeline computes the blaze function of each order and stores it into "blaze" files |
Instrumental Profile | from Fabry-Perot images, the pipeline modelizes the instrumental profiles, or "shape" of the pseudo-slit, at all locations in the spectrum and stores it into "tilt" and "shape" files |
Wavelength Calibration | from Fabry-Perot and Hollow-Cathod images, the pipeline produces a wavelength map "wave" for each fiber |
Science Observations (Detailes information in Data Products: File Structure ) |
e files | 2D extracted spectra that use the instrument profile and order localization and performs optimal extraction. |
s files | FITS table containing the 1D extracted and rebinned spectra, for each channel (AB, A, B, C). |
p files | Polarimetric products are data packages only processed in polarimetric mode, from the combination of 4 consecutive exposures. |
t files | 2D spectra in the same format than e spectra, after the correction of telluric lines has been applied. |
v files | FITS table containing the radial velocity of the star extracted from the CCF. |
Some keywords explained (in main or in extension headers) |
VERSION | DRS version |
DPRTYPE | Type of exposure configuration (OBJ_FP or OBJ_DARK means there is a star on channels A and B and a Fabry-Perot or Dark on channel C) |
TRG_TYPE | Type of science exposure: object or sky |
EXTNAME | Name of the extension (A, B, AB or C) |
CRVAL1 | Value of the first wavelength bin in nm for s files |
CDELT1 | Bin size in nm for the s files (typically 0.005nm) |
NAXIS1 | Number of data points in the s files, per extension |
WAVEFILE | Name of the relevant wavelength solution file for e, t, and p files |
OBJECT | Target name |
DATE-OBS | UT date of the exposure, in the format yyyy-mm-dd |
UTC-OBS | UT hour corresponding to the start of the exposure in hh:mm:ss.ss |
MJD-OBS | Modified Julian Date at start of observation |
EXPTIME | Exposure time in seconds |
AIRMASS | Airmass |
SPOZPMED | Median of zero point absorption from SkyProbe during the exposure (optical band, in magnitude) |
SGCSEE | Seeing measured during acquisition (not always) (") |
SGSSEE | Seeing estimated on guide images with star in the hole (") |
SBRHB1_P | Rhomb position in drawer 1 |
SBRHB2_P | Rhomb position in drawer 2 |
EXTSN034 | S/N per pixel in DRS order 34 (1.65mic) (the keyword in DRS 0.5 or older versions was SNR34) |
SPEMSNR | S/N at 1.65mic measured by the exposuremeter at the end of the exposure |
SGCMAGN | Magnitude estimated on the guide images with star in the hole |
BJD | Barycentric Julian Date (in processed files) |
BERV | Barycentric Earth Radial Velocity (km/s) |
CCFRV | Raw Stellar Radial Velocity in channel AB (km/s) |
WFPDRIFT | Drift of the input Fabry-Perot with respect to the FP mask (computed by cal_WAVE) (km/s) |
RVDRIFT | Drift between the wavelength solution and the stellar spectrum (computed by cal_CCF) (km/s) |
CCFRVC | Stellar Radial Velocity on channel AB, corrected from the instrumental drift (km/s) |
CCFFWHM | Full width half maximum of stellar cross correlation function on channel AB (km/s) |
CCFCONT | Contrast of stellar cross correlation function on channel AB |
CCFLINE | Number of lines used in the cross correlation with the stellar mask (for AB fibers) or the FP mask (for C fiber) |
DVRMS | RV photon noise uncertainty on the stellar spectrum (for AB fibers) or the FP spectrum (for C fiber) (computed by cal_CCF) |