Spectroscopic Processing Workshop: Calibration & Reference Sources - IAP 24 Nov 2005

1. Workshop First look, calibrations, reference sources IAP – 24 November 2005 • CU6 structure • Aims of the workshop / open questions

2. CU6 structure DU1000 Management of the coordination unit DU2000 Database & data analysis architecture DU3000 Spectra extraction & background modelling DU4000 Data sanity check & quick calibrations DU5000 Nominal calibrations DU6000 Meta-processing DU7000 Single stars radial & rotational velocities DU8000 Multiple stars radial & rotational velocities DU9000 Stability/variability assessment “CU6 spectroscopic processing development plan” (Version 1: December 2005)

3. Example of WBS: DU6000 Meta-processing • WP6100 Management of DU6000. • WP6200 Apply calibrations. • WP6300 Clean spectrum. (or in background modelling) • WP6310 Filter defective pixels. • WP6320 Filter optical defects (ghosts, …). • WP6320 Filter cosmic rays. • WP6400 Normalize to continuum. • WP6500 Combine observations. • WP6510 Examine/use astrometric and photometric information. • WP6520 Examine/use evolution of spectral morphology. • WP6530 Examine/use radial and rotational velocities information. • WP6540 Use available information and optimally combine spectra. • WP6600 Spectra transforms • WP6610 Fourier transforms. • WP6620 Wavelet transforms. • WP6700 Filter noise • WP6710 Overview of existing techniques. • WP6720 Filter noise in Fourier space. • WP6730 Filter noise in wavelet space.

4. Example of WBS: DU7000 Single star radial & rotational velocities • WP7100 Management of DU7000. • WP7200 Auxiliary data: general. • WP7210 Define & summarize needs and build test data set. • WP7220 Define and summarize needs for template spectra. • WP7230 Manufacture masks. • WP7240 Define/build library of rotational velocity standard • WP7250 Implement auxiliary data access methods. • WP7300 Auxiliary data: radial velocity standard. • WP7310 Define list of potential calibration stars. • WP7315 Observe potential calibration stars. • WP7320 Derive RV of potential calibration stars. • WP7325 Identify stable stars. • WP7330 Assess RV shift due to instrum./wavel. range/techniques. • WP7360 Define list of potential calibration asteroids • WP7365 Simulate the observation of potential calibration asteroids • WP7370 Assess consistency asteroid/star for RV zero point. • WP7375 Observe asteroids. • WP7380 Assess performance with observed asteroids. • WP7400 Radial velocity derivation methods (including error assess.). • WP7410 Overview of existing techniques. • WP7420 Cross-correlation in data space with template. • WP7430 Cross-correlation in data space with mask. • WP7440 Cross-correlation in Fourier space. • WP7450 Minimum distance method. • WP7500 Rotational velocity derivation methods (including error assess.). • WP7510 Overview of existing techniques. • WP7520 Width of correlation peak. • WP7530 Fourier transforms. • WP7540 Minimum distance method. • WP7550 Neural network. • WP7600 Identification/correction of outliers. • WP7610 Overview of existing techniques. • WP7620 Boot strap. • WP7700 Comparison of method performance. • WP7710 Define comparison criteria. • WP7720 Compare methods and synthesize results. • WP7800 Assessment of radial velocity astrophysical zero point. • WP7810 Review and define effects that should be taken into account. • WP7820 RVS to solar system barycentre reference frame transform (under CU3 responsibility?). • WP7830 Gravitational redshift.

5. Aims of the workshop • Discuss the 3 related issues of First look, calibrations and reference sources → direct discussion/brainstorm: questions, present different approaches & different points of view • Address / answer some specific question • Try to define an high-level overall approach for first look / calibration: i.e. baseline scenario(that will be iterated/modified). • Define methodology to refine WBS

6. First look • Tasks of first look? • Check good health of the instrument? • Check good health of the spectra? Which spectra? How many spectra? • Perform quick calibrations? Use the nominal calibration algorithms with different input data? • Check scientific performance? • ...? • Frequency? Daily basis? Monthly basis (weakest spectra)? • Methods? • Auxiliary data? Dedicated observing program(s)?

7. Nominal calibrations • Which instrumental quantities should be calibrated? How? • How frequently should the nominal calibrations be performed? weekly? monthly? Why? Is there a gain in continuity over several days/weeks? Are there long-term effects to calibrate (e.g. over one precession period? e.g. over one year?)? • Volume/type of calibration data? • Auxiliary data? Dedicated observing program(s)? • Is the “global iterative approach” appropriate for all calibrations?

8. Reference sources • Type of standards? Qualified before/during the mission, by us/by others. • How to identify standards? How to qualify standards? How to achieve absolute RV at the 300 m/s level? Are some software developments required? • How many standard will we qualify? How many will others qualify? • How to test the performance of RV standard for SGIS?

9. Agenda 10:00 – 10:40 Introduction 10:40 – 11:30 Overview of first look 11:30 – 12:20 Overview of the calibrations 12:20 – 13:00 An example: wavelength calibration 13:00 – 14:10 Lunch 14:10 – 15:00 Radial velocity reference sources 15:00 – 16:30 Synthesis discussions