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1. Multiple observations from the same OB have not been combined Release Notes The data reduction used the standard UVES pipeline recipe uves_obs_scired Find a de scription of the science recipe in the User Manuals All recipe parameters used were default except for e reduce extract kappa 20 threshold for cosmic ray rejection default is 10 and was applied in many cases choice changed over time e reduce ffmethod pixel with pixel flat fielding is done in pixel pixel space before extraction the alternative option is extract in pixel order space after extrac tion which is the default the pixel method has been chosen for all data with central wavelength gt 760nm to suppress residual fringes from the flat field which would remain with extract the pixel method has the disadvantage to introduce some arti facts at the order begin and end therefore it needs a reduction of the inter order over lap and thereby creates larger spectral gaps in the red wavelength ranges beyond 880 nm the extract method has been chosen for all data with central wavelength below 760nm e xreduce merge delti 14 and reduce merge_delt2 4 related to the previ ous point this is the amount in pixels of the order begin and end to be truncated on ly applied to data with central wavelength 2 760nm The extraction method reduce extract method was optimal for the normal non sliced ECHELLE data Bec
2. can be neglected Then the extracted orders are wave length calibrated using the line tables rebinned and merged This is the final step if no master response curve is available otherwise that calibration solution is used to flux calibrate the extracted spectrum If so the spectrum is delivered in physical units Otherwise it comes in arbitrary units counts and contains those instrument or atmospheric signatures which cannot be removed by the flat field chromatic coating efficiencies atmospheric extinction or have been added by the flat field spectral response of the calibration lamp Check out the on line version for illustrations of the steps and products Note that in the case of the absorption cell data the signature of the iodine cell has not been removed There are flat field data available from the ESO archive with the iodine cell turned on It was felt that the reduction with these calibration data is too delicate to be executed in an automatic way The reduction of the SLICER data follows exactly the same steps and uses the same types of calibrations as the reduction for the non sliced ECHELLE data The only exception is the ex traction method linear The flux calibration has been applied for the following central wavelengths 346 390 437 564 580 760 and 860 nm The UVES Echelle products are wavelength calibrated No corrections for barycentric or heli ocentric motion have been applied The corresponding value
3. features and issues The pipeline applies some assumptions on the source these assumptions apply to the non sliced case e If there is more than one target in the slit it always extracts the brightest source e If the cross dispersion profile of the source is not Gaussian the UVES pipeline may create artifacts wrong extraction This may either happen due to an extended source or for very high counts close to or at saturation A typical symptom of non Gaussian profiles are ripple artifacts Flux calibration The flux calibration is good enough for obtaining a coarse energy distribu tion but is not of spectrophotometric quality The slit losses are unknown and many observa tions did not care about photometric conditions The master response curves have been de rived from carefully selected individual standard star observations but they are applied to science data sometimes taken a long time before or after in many cases years apart There has been no attempt to correct for these long term effects The flux calibrated spectra are provided in units of 10 erg cm2 s Angstr m Wavelength range of flux calibrated spectra some of the master response curves used for flux calibration have the initial and the final 25 Angstrom cut off hence the flux calibrated spectra have a slightly smaller wavelength range than the extracted ones Spectral gaps For spectra of the RED arm increasingly larger gaps occur beyond about 880 nm related to
4. ECHELLE SLIC lt n gt n 1 2 3 or ECHELLE ABSORPTION CELL SLIC 3 where SLIC stands for slicer not FIBRE e category DPR CATG SCIENCE e type DPR TYPE OBJECT or OBJECT POINT not OBJECT EXTENDED Note that the largest fraction of UVES point source data comes as normal ECHELLE about 80 90 Second largest fraction is ECHELLE SLICER about 10 The remaining few per cent divide into ABSORPTION CELL data with or without the SLICERs Physical slicers come in three different varieties which however has no impact on the data products A priori no selection is made on the basis of observing mode visitor or service nor on set tings UVES ECHELLE settings are defined by the combination of binning central wave length and dichroic filter De facto we can process only those science data for which certified master calibrations can be found in the archive These master calibrations were also processed by the Quality Control Group but much earlier in time close to the date of acquisition in order to provide quick quality feedback to the Observatory The operational selection pattern for master calibrations evolved over the years It reflects pipeline evolution and calibration plan changes and also manpower constraints In the early years of UVES the processing focus was on calibrations taken in standard settings based on central wavelength and for Service Mode SM science data The fast read mode 4port 625kHz was not supported
5. ESO Phase 3 Data Release Description Data Collection UVES_ECHELLE Release Number 1 Data Provider ESO Quality Control Group Document Date 06 05 2015 Document version ILZ Document Author Reinhard Hanuschik On line version http www eso org qc PHOENIX UVES ECH processing html Changes with respect to the previous version Data taken with one of the Image Slicers 1 2 or 3 have been added to the release starting with ob serving date 2003 04 14 Abstract This is the release of reduced 1D spectra from the UVES spectrograph ECHELLE mode as opposed to the FIBRE mode point sources as opposed to extended sources taken without or with the image slicer Data taken with the absorption cell are also included in the data re lease This release includes re processed UVES data as well as current and future UVES data not processed before at ESO The processing scheme is as homogeneous as possible The selected data cover the vast majority of the entire UVES data archive from the begin of operations in March 2000 until present The data have been reduced with the UVES pipeline versions uves 5 1 3 and higher recipe uves_obs_scired All data have their instrument signature removed de bias flat fielded with the exception of the absorption cell data which have the signature of the iodine cell not removed Then the data have been extracted wave length calibrated and order merged Whenever possible they have been flux calibrated The p
6. ause of the multiple stellar signal in case of SLICER data 3 5 de pending on the slicer used these were extracted with the linear method In optimal mode the pipeline uses an initial SNR estimate based on which it selects the appropriate cross order extraction profile Gauss Moffat Virtual Find more details in the User Manuals sec tion 11 1 13 6 under the UVES link in http www eso org sci software pipelines Master Calibrations used for data reduction name first part type pro catg mandatory optional content MASTER _BIAS_ ccd UV_MBIA mandatory master bias created from 5 raw bias frames removes bias level and bias structure ORDER_TABLE ccd UV_PORD mandatory order table contains a description of the echelle order position used for extraction LINE_TABLE_ ccd UV_PLI1 3 or UV_PLIN line tables either three one for each third of the extraction slit or one for mandatory the whole slit giving the dispersion solution for the extracted spectra MASTER_FLAT ccd UV_MFLT mandatory master flat created from three raw flats used for removing gain noise removing the echelle function removing slit noise introducing lamp response MASTER_RESPONSE _ ecd UV_MRSP optional response curve used for flux calibration derived from selected sets of standard star measurements collected for most but not all standard settings removes lam
7. cted to be useful for any kind of high resolution spectroscopic research including line profile studies and radial velocity studies For studies of energy distributions the investigator should keep in mind that the UVES instrument is a high resolution spectrograph designed for stability and throughput but not for high precision flux calibration There are slit losses and many obser vations did not care about photometric conditions Disclaimer Data have been pipeline processed with the best available calibration data How ever please note that the adopted reduction strategy may not be optimal for the original sci entific purpose of the observations nor for the scientific goal of the archive user You may also want to consult the on line version of this documentation which is a living document and has further useful links and more details Release Content The UVES_ECHELLE release is a stream release The overall data content is not fixed but grows with time as new data are being acquired and processed approximately with monthly cadence and with a delay of 1 or 2 months The data is tagged with UVES_ECHELLE in the ESO archive user interfacet The first data were published under UVES_ECHELLE in September 2013 with UVES data from the begin of operations March 2000 until May 2013 The archive is being filled chrono logically New data taken after May 2013 are being added at roughly monthly intervals and with a delay of 1 or 2 mont
8. e ORIGFILE product name e g UV_SFLX_ 58146 2001 09 13T09 12 30 326 RED564d1 2x2 21 fits has the components ORIGFILE UV SFLX 58146 2001 09 RED564d1 2x2 21 fits component 13T09 12 30 326 refers to UVE product OBID timestamp of setup string RED or BLU for S type raw file the arm 564 central SFLX or acquisition wavelength in nm d1 d2 re bl 10 Find examples under http www eso org observing dfo quality PHOENIX UVES ECH processing html features SRED or archival d1 d2 for the use of both arms SREA with dichroic filters 1 or 2 where S re bl for use of the red or blue stands for arm only 2x2 binning 21 slit science width 2 1 arcs Due to the data format of UVES raw data the UVES products with d1 or d2 in their name always come as a BLU RED twin taken almost simultaneously although not necessarily with identical exposure times File structure The UVES products come as binary fits table with multi column format The columns are labeled as follows a non SLICER data column label content UV_SRED UV_SREA 1 WAVE wavelength in Ang strom 2 FLUX_REDUCED extracted wave length calibrated sky subtracted SCI ENCE signal not fluxed 3 ERR_REDUCED corresponding error not fluxed 4 BGFLUX_REDUCED extracted and wave length calibrated sky signal not fluxed 5 FLUX like 2 but flux calibrated physical u
9. either Later the calibration scheme was extended to non standard settings at best effort basis ignoring the Ser vice Visitor Mode VM distinction Therefore the completeness ratio for the UVES Echelle science data in this stream is inhomo geneous For the early years until 2002 almost no VM data are included and no SLICER da ta Later the fraction is close to complete Processed SLICER data are available as of 2003 04 13 Note that the fact that a certain UVES raw file does not have a product in this release does not imply a quality issue with the raw data It is more likely that this raw file falls into the catego ry of VM science taken in the early years of UVES in non standard settings or in the fast read mode Such data would most likely process fine manually In general the master calibrations were processed with different earlier pipeline versions than the science data in this stream This is not considered an issue since the calibration reci pes of the UVES pipeline did not strongly evolve with time Science data with the PROG ID starting with 60 or 060 have been de selected considering them as test data Data taken at daytime with obviously wrong SCIENCE tag have been ignored Otherwise the metadata tag SCIENCE has been blindly accepted from the raw data originally defined by the PI thus including sometimes standard stars This is often evident from the OBJECT metadata key Also there are rare cases whe
10. hs when all master calibrations for the corresponding time inter val are available This release of the UVES Echelle processed data supersedes the earlier version called UVES reprocessed processed in 2007 The main differences to the earlier version are e completeness the earlier release covered data until March 2007 only and had no SLICER data this release includes post 2007 data and SLICER data and will be sus tained into the future e the quality issue with the 860 nm data is solved e flux calibration is also available for the 760 nm setting e product data come in the binary table format 1D spectroscopic standard with one product file for the BLUE arm data and one product file for the RED arm data How to organize The downloaded data come with their technical archive names The README file coming with every download contains the information necessary to properly rename the files and establish their association The fundamental unit of the renaming process is to capture col umn 2 in the README file technical name starting with ADP and column 3 original name starting with UV_ and use something like mv 2 3 Data Selection Data selection is entirely rule based It is organized along the following criteria 3 http www eso org gc PHOENIX UVES_ECH processing html http archive eso org wdb wdb adp phase3_spectral form e instrument UVES e observing technique DPR TECH ECHELLE or ECHELLE ABSORPTION CELL or
11. ipeline output products have been converted to the 1D standard binary table The processing is performed by the Quality Control Group using a dedicated workflow tool in an automated process The pipeline processing uses the archived closest in time quality controlled and certified master calibrations It is important to note that the reduction process itself is automatic while the quality assessment and certification of the master calibrations was and still is human supervised The overall data content is not fixed but grows with time as new data are being acquired and processed approximately with monthly cadence and with a delay of 1 or 2 months The data format follows the ESO 1D spectroscopic standard for so called phase 3 data prod ucts Each spectrum is a multi column binary table There is one product file for each parent raw file The typical observing pattern of a simultaneous observation in the blue arm and in the red arm is propagated to the data products there is one blue product and one red product if the original observation used both arms This data release offers science grade data products with the instrumental signature re moved flux calibrated if possible with error estimates and a list of known shortcomings 1 http www eso org sci facilities paranal instruments uves 2 http www eso org sci observing phase3 p3sdpstd pdf These data products are considered to be ready for scientific analysis They are expe
12. kindly reminded to notify Mrs Grothkopf esodata at eso org upon acceptance or publication of a paper based on ESO data including bibliographic references title authors journal volume year page numbers and the programme ID s of the data used in the paper 2 http archive eso org cms eso data access policy html 10
13. n test observations were exe cuted under the SCIENCE label Most very short exposures with no signal fall into that cate gory but have not been suppressed 5 more under http www eso org gc UVES pipeline settings html All data both with and without the SLICERs have been processed up to the wavelength cali bration step The last step the flux calibration was undertaken with master response curves see below These do not exist for all settings not even for all standard settings The products which could be flux calibrated have the highest reduction level FLUXCAL ABSOLUTE ORIGFILE names start with UV_SFLX while the others have FLUXCAL UNCALIBRATED names start with UV_SRED if taken without slicer and without absorption cell UV_SREA without slicer with absorption cell UV_SRES with slicer without absorption cell or UV_SREB with slicer and absorption cell There are SLICER data which could be flux calibrated taken e g in the 580 setting their ORIGFILE name also starts with UV_SFLX There is no raw data selection based on quality Likewise we have not considered OB grades the observations might have any grade between A and D or X The availability or non availability of a particular file in this release does not infer any claim about the data quality E g saturated pixels are not flagged by the pipeline The user is asked to carefully check the data for those cases Each product file has exactly one parent raw file
14. ng red segments have been merged in a single spectrum with non equal sampling and no degradation There is always an unavoidable gap between the two spectral segments due to the geometrical gap between the two red detectors Data Quality There is some internal quality control on the pipeline process monitoring e quality of the association checking that the master calibrations are not older than a few days e score flag for number of saturated pixels in the raw data e QC reports and quick views This information has largely been used to improve and fine tune the processing process An individual one by one inspection of the products has been unaffordable SNR the signal to noise ratio of the spectra is measured by the ratio of FLUX ERR or FLUX_REDUCED ERR_REDUCED giving the equivalent result Its chromatic slope is as complex as the spectrum itself As representative numbers the pipeline calculates an average per echelle order stored in the header per order as HIERARCH ESO QC ORDnn OBJ SN for BLU spectra and as HIERARCH ESO QC CHIPi ORDnn OBJ SN for RED spectra From these numbers a median has been calculated omitting the respective first and last order which is the number quoted as SNR on the query interface and in the header Note that as a peculiarity in the red wavelength ranges those files reduced with the re duce ffmethod pixel method have a higher SNR in the spectral regions with overlapping echelle orders Known
15. nits 6 ERR like 3 but flux calibrated physical units The UV_SREA products have the absorption line spectrum of the absorption cell not removed they are reduced in exactly the same way as the data without absorption cell b SLICER data column label content UV_SFLX UV_SRED UV_SREA 1 WAVE wavelength in Ang strom 2 FLUX_REDUCED extracted wave length calibrated sky subtracted SCIENCE signal not fluxed 3 ERR_REDUCED corresponding error not fluxed 4 FLUX like 2 but flux calibrated physical 1 http www eso org sci observing phase3 html units 5 ERR like 3 but flux calibrated physical no units In the case of the red spectra the header contains keywords from both pipeline products re member the pipeline delivers one spectrum per detector and these are merged into the single 1D binary fits table distinguished by a field CHIP1 or CHIP2 resp in the keyword name File Size The UVES products have about 3 MB size for the unbinned 1x1 RED arm and 2 MB for the unbinned BLU arm Binned products 2x2 come at half this size Files are always uncom pressed Acknowledgment text According to the ESO data access policy all users of ESO data are required to acknowledge the source of the data with an appropriate citation in their publications Find the appropriate text here All users are
16. p response and remaining instrument signature EXTCOEFF_TABLE used to correct for extinction optional optional ccd BLUE REDL REDU if missing pipeline fails if missing final product is not flux calibrated This list is the same for data taken with and without the image slicers Pipeline Description Information about the UVES pipeline including downloads and manual can be found under the URL http www eso org sci software pipelines The QC pages about UVES data contain valuable information about the UVES Echelle data their reduction and the pipeline recipes Data Reduction and Calibration The QC pages about science reduction describe the details of the main reduction steps In essence the bias level and structure is removed Then depending on the flat fielding method either the science data are divided by the flat and then extracted using the order table pixel method or the other way round extract Upon extraction the optimal extraction algorithm determines the sky background and removes the cosmics SLICER data being extracted with method linear meaning a simple summing up of the total signal in the extraction slit have no sky background determined the observing method is suitable for bright sources and short 7 http www eso org gc UVES pipeline pipe_gen html 8 http www eso org gc UVES pipeline recipe_science html exposure times hence sky background
17. s have been calculated by the pipeline from the observation and are stored in the header HIER ARCH ESO QOC VRAD BARYCOR or HELICOR in km s No correction for telluric absorption lines has been applied In some cases the PIs have specified attached arclamp or flat calibration during the night immediately after the science data We do not guarantee that these special calibration data have been used for the reduction More likely is that the standard daytime calibrations have been applied The UVES pipeline creates the following product files e extracted spectrum de bias flat fielded extracted wavelength calibrated and re binned e corresponding error file e non SLICER data only background underlying the signal in the slit sky by product from the extraction step e fluxed spectrum if flux calibration available e corresponding fluxed error if flux calibration available While these pipeline product files are separate image fits files they are finally converted into a single binary table fits file which is the delivered data product with the wavelength scale as first column and all other products as further columns see File Structure below Contrary to the product files of the UVES pipeline which generates one product for each de tector the converted product from the RED arm as downloaded from the archive is a single 9 http www eso org qc PHOENIX UVES ECH processing html file The two non overlappi
18. the pixel flat fielding algorithm These gaps would be much smaller with the extract algorithm which however has strong artifacts from the fringes in the flat field It was felt that the spectral gaps are of minor impact in general An investigator interested in the spectral information in those gaps might want to manually reduce the data with the extract method Flat field signatures in particular the 346 nm spectra have relatively strong signature of the flat field extraction repeating ondulations on the scale of one echelle order Quite rarely the 860 REDU spectra have flat field related artifacts at the begin of echelle or ders right after the order gaps Find more documentation about features and issues on line Data Format Files Types There exist five different file types depending on the reduction level flux calibrated or not and on the product category ORIGFILE product category Description names start PRO CATG ing with UV_SFLX FLUXCAL_SCI_POINT_ lt arm gt flux calibrated product arm RED or BLU UV_SRED RED_SCI_POINT_ lt arm gt extracted and wavelength calibrated but UV_SREA same for unfluxed product arm RED or BLU RED_SCI_ABSCELL_RED absorption cell data UV_SRES same for RED_SCI_SLICER_ lt arm gt SLICER data UV_SREB same for RED_SCI_SLICABSCELL_RED SLICER data with absorption cell The following naming convention applies to th

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