1. HARPS Data Flow System Christophe Lovis Geneva Observatory HARPS-N PDR, 6-7 December 2007, Cambridge MA

2.  Data flow overview  Short-time scheduler  Calibrations and observations  Data reduction software  Archiving  Data reprocessing and analysis  Some important points Outline

3. STS OS/ICS TCS Trigger + DRS instrument machine observer machinetelescope machine reduction machine OB , , … RAW GUIDING IMAGES DAU RAW REDUCED Data flow overview RAW GUIDING

4. Interfaces Short-time scheduler OS / ICS Trigger / DRS TCS Set of parameters (coordinates, observing mode, etc.) Raw frame with FITS header Telescope parameters

5. The RITZ control room

6. The short-time scheduler (STS)

7. Real-time scheduling of observations Possibility to prepare the night in advance Easy-to-use cut-and-paste graphical interface Input from catalogues: object name, coordinates, proper motion, approximate RV, spectral type, observing mode, desired SNR Real-time computation of observing conditions (position on the sky, airmass, moon, …) Exposure time computation using built-in ETC

8. Calibrations and observations « Standard calibration » sequence to be executed at the beginning of each night: Bias measurement Order localization Flat-fielding Wavelength calibration Observations can be made in 3 different modes: Object + simultaneous reference Object + sky Object only -> Preparation of calibration and observation plan

9. The online pipeline (trigger + DRS)

10. The offline trigger + DRS

11. Data reduction software Major reduction steps for science raw frames: 1.Bias and dark subtraction 2.Order extraction with cosmic rejection 3.Flat-fielding 4.Wavelength calibration 5.Barycentric correction 6.Merging and rebinning of the orders 7.Cross-correlation with stellar template 8.Radial velocity and CCF bisector computation 9.Instrumental drift correction (if applicable) 10.Creation of reduced data products (FITS format)

12. Data reduction software Calibration recipes: bias & dark, order definition, flat-fielding, wavelength calibration Science recipes: object+sim. reference, object+sky, object only Calibration database Instrument + DRS configuration files Log files RAW CALIBRATION FRAME RAW SCIENCE FRAME REDUCED CALIBRATION FRAMES REDUCED SCIENCE FRAMES

13. Data reduction software Still to be done: Adapt DRS to HARPS-N (spectral format, keywords, etc.) Adapt wavelength calibration to laser comb / Fabry-Perot Correct background / straylight pollution Optimize reduction of low-SNR data Improve instrumental drift computation Update barycentric correction process Optimize cross-correlation process Develop/extend stellar diagnostics (Ca II H&K index, bisectors, study of individual line shapes/shifts, …)

14. Data archiving unit (DAU) -Raw frames -Reduced frames -Log files -Guiding images transportable media FTP ? Data archive Cambridge / Geneva

15. DRS updates and data reprocessing/analysis DRS continuously improved and updated Coherence of the data is essential! Periodic global reprocessing of the whole archive to always have the best-quality data Extraction of the relevant information from all FITS headers and creation of a global database Use of external tools to search for planetary signals (period search, orbit fitting, genetic algorithms, significance tests, etc.)

16. Some important points For the project: Precisely define all interfaces (STS – ICS, FITS headers, etc.) and if possible keep close to HARPS-S choices Use PM counting to determine the photocenter of the exposure Need for perfect guiding and record integrated guiding image While observing: Always keep an eye on the guiding! Carefully check ALL target-related parameters (coordinates, spectral type, …) in the input catalogues to avoid any spurious RV effects