|UVES and FLAMES/UVES:
Data packages have been delivered for period P87 (April-September 2011) and before. For new data, acquired after the begin of October 2011, data packages are no longer created. Users can access their raw data in electronic form through the ESO User Portal.
Data for VLT pre-imaging runs are processed and delivered as before.
For completeness, the structure of the historical packagesis described below.
Science data have been processed by the pipelines with the best available calibration data. Please note that ESO is not assuming any responsibility in respect to the usefulness of the reduced data. The adopted reduction strategy may not be suitable for the scientific purpose of the observations.
The top-level structure of the data package is as follows:
For each observation block (OB) that has been executed on Paranal, you find all measured raw data (FITS files) in a directory named by the OB number (FITS key HIERARCH.ESO.OBS.ID). If pipeline products exist, these are also added in the OB directory.
The GEN_CALIB directory collects all those calibration files (raw and products) that have been measured as part of the regular calibration plan, and calibration frames of a general nature (like static line tables). The GEN_INFO directory has general information, like data reports and night logs.
The tree shown above is the logical structure, which means that this is the way the data have been organized before they have been put onto media. Depending on the size of your package, the directories may be distributed across several media. It is a good idea to create the original tree on your local disk and then copy all files from the media into this tree.
<OBS_ID> (e.g. 179211)
For each executed observation block of your run, the package contains a directory with all measured data from that OB. All data under <OBS_ID> carry your run ID.
Note that some of your OBs may have been executed more than once. In particular, if time permitted, observatory staff try to re-execute OBs which produced data clearly out of the specified constraints. Check out the NIGHTLOG.html file for details (go to "OB information"). All data from OBs that have been executed multiple times are found in the same directory.
Each OB directory is further subdivided into subdirectories for science frames, calibration frames, and log files. In many cases, there will be science data only, but there may also be OBs with attached calibration data:
The data package contains the following report files:
The executable script print_all_reports under GEN_INFO/scripts can be used to print all postscript files in your package.
Known IRAF problems
Stand-alone FITS handling toolsFind information about FITS header handling tools (e.g. dfits, fitsort, hierarch28) here.
The rest of this page contains an overview of the structure and content of the data packages for UVES as a standalone instrument (also called UVES-Echelle) and for UVES as part of the FLAMES instrument (FLAMES/UVES, UVES-MOS, or UVES-Fibre). FLAMES programmes using both UVES and GIRAFFE spectrographs ("COMBINED mode") receive two separate sets of media, one for the FLAMES/UVES data and one for the FLAMES/GIRAFFE data. Both sets are usually shipped in one single package.
The description of the Service Mode package for FLAMES/GIRAFFE data is found here.
For further information about UVES data and QC have a look at:
The UVES raw and processed calibrations are mostly produced by the calibration plan. Only exception are attached flat calibrations as specified by the user.
More about calibrations ...
The GEN_CALIB directory for UVES data is structured as follows:
This directory collects all raw calibration frames that are associated to your science data, and that have been measured as part of the regular calibration plan. It also contains their pipeline products and calibration frames of a general nature (like static line tables). Calibrations that have been measured by user-defined OBs and that have been used for pipeline processing of science data may be included here in addition. The directory has four subdirectories, gen, logs, proc and raw. The proc and raw directories have further fine-structure:
Calibration products derived from the raw calibrations. Please look
at the UVES
calibration pipeline or UVES-MOS
calibration pipeline pages for descriptions of the products.
The renaming scheme for UVES and FLAMES/UVES CALIBRATION product files can be found
You can expect the following static calibrations in the gen directory
Additional or missing raw calibration files may be retrieved anytime from the ESO Archive. Calibration data are public while SCIENCE data have a proprietary period of one year.
Some notes on calibration frames
For operational reasons, calibration products are created only for standard configurations. No solutions are produced for non-standard configurations. Hence such SCIENCE data are not reduced either. The UVES pipeline may well be able to reduce such non-standard data.
Bias frames usually come in sets of five raw files which are stacked to one master bias. They are provided only once per week since they are in general very stable.
The order definition flats (and the format check frames, usually not delivered) are for pipeline use. They are required for automatic recognition of the spectral format. If you plan to reduce your data with your own software, or with MIDAS in interactive mode, you will not need them.
UVES-Echelle flat fields: Day-time lamp flat fields usually come in sets of five raw files which are stacked into one master flat. The extreme blue settings (WLEN = 346 nm) have two different types of lamp flats: those taken with the usual flat lamp, and those taken with a deuterium lamp which provides higher response in the UV but has emission lines at longer wavelengths (see User Manual). Both sets of flats are delivered. Master flats are also created from both sets. The automatic pipeline reduces science data with the normal master flats only. Two different sets of flats also exist for science data using the Iodine absorption cell (600 nm): one using the normal flat lamp and one using the lamp plus the absorption cell. Both sets are delivered and used for master flats. The automatic pipeline uses only flats without absorption cell
UVES-MOS flat fields: There are two different varieties. The fibre flat fields are used to recognise the fibre postitions on the CCD frame. They come in sets of three raw files which have only odd numbered fibres, only even numbered fibres, or all fibres illuminated, respectively. Corrections of the blaze function and of pixel-to-pixel variations are provided by slit flat fields. They are taken at three different slit positions with a stack of (typically) three frames at each position.
Flux calibration (UVES-Echelle): For the purpose of flux calibration, a set of master response curves (UV_MRSP) is available in the GEN_CALIB/gen directory (for 346, 390, 437, 564, 580, and 860nm only). Further information about response curves and flux calibration can be found here.
Known reduction problems (UVES-Echelle)
Instrumental artefacts. Please look at the page about recent problems for recently discovered instrumental artefacts that are not yet mentioned in the User Manual.
High signal. Optimum extraction may face problems in cases of high signal. Check out here for details.
High airmass. In cases of blue spectra taken at high airmass (> 1.5), without the ADC, atmospheric dispersion may shift the bluest orders out of the extraction window, and their flux is lost to the automatic pipeline procedure. The data can, however, be recovered by manual extraction. Even at airmass 1.1, differential extinction spreads the spectrum by about 3 pixels for the bluest setup (346 nm).
Order indentification. In a few cases problems have occured with order identification in settings with 346nm central wavelength: the orders found by the pipeline in the order defintion flat and during extraction/wavelength calibration of the science frame may be different. This is not recognised by the pipeline and the lines in the final wavelength-calibrated spectrum appear shifted by one order. An example is given here where the overlap between an observation with 346nm and 437nm central wavelength is shown. The problem may be resolved by choosing a different order definition flat.
Sky emission lines. Optimum extraction may over/under-corrected bright sky emission lines by 5% or more.
Artificial lines. Series of artificial lines are occasionally
seen around 607 nm and 638 nm in spectra reduced with optimum extraction.
These features may be mistaken as telluric or real physical lines.
Attached red flats. The recommended exposure times for attached
flat fields as given in UVES user manuals until version 19/02/2003 (including)
have been longer than the values used for day-time calibrations. Therefore,
one or two orders in the upper (MIT) chip of attached flats taken with
the FF4 lamp (used for 860nm settings) may have maxima above 40000 ADU.
This chip is not linear any more in this region and saturates soon.
It is recommended to check carefully attached flats taken with FF4 before
using them for calibrating science data. Flat fields taken with other
lamps or taken within the regular day-time procedure are not affected
by this problem.
BIAS level. Note in cases of high-precision reductions of faint
sources taken in 2x2 binnings that there is a temperature dependence
of the mean BIAS level especially for the red upper CCD, by about 2
Seeing. If the seeing encountered during the SCIENCE exposure
is less than the slit width, it might happen that wavelength shifts
are introduced in the SCIENCE data if the object is not perfectly centered.
This may be checked and corrected, at least in the red, with the telluric
Radial velocity correction. Until 2001-09-17 (date of acquisition),
a bug in the radial velocity correction as calculated by the pipeline
may have caused wrong values. Please check carefully (FITS keywords
HIERARCH ESO QC VRAD BARYCOR and HELICOR; also stated in the listing
file 'list_of_all_red.txt'). Remember that no correction is applied
to the data. This bug is present in version 1.2 and earlier of the uves
pipeline, and solved with version 1.3.
Known reduction problems (UVES-MOS)
Instrumental artefacts. Please look at the page about recent
problems for recently discovered instumental artefacts that are
not yet mentioned in the User Manual.
Extraction of 860nm data. The part of the spectra above 980nm
is usually not extracted well by the pipeline recipe.
High signal. Optimum extraction may face problems in cases of high signal. Check out here for details.
Artificial lines. Series of artificial lines are occasionally seen around 607 nm and 638 nm in spectra reduced with optimum extraction. These features may be mistaken as telluric or real physical lines.
Errorbar values. The values in the ERR_MWXB_SCI files are about a factor of two higher than the statistical 1sigma errors.
UVES solar spectrum