1. ST–ECF UC, Dec 01 1 NGST support at the ST-ECF Bob Fosbury http://www.stecf.org/~rfosbury

2. ST–ECF UC, Dec 01 2 NGST@ECF Current activities Science oversight: ISWG (NASA), SST (ESA) Performance studies Simulations PR Future plans Support of European instrument procurement process Provision of ESA contribution to Science Operations

3. ST–ECF UC, Dec 01 3 ESA-NASA top level schedule 2000 2001 2002 2003 2004 2005 2006 2007 2008 2009 12/01 05/01 02/02 09/0303/04 09/04 06/09 12/06 Activity NASA Phase 1 (A/Early B) Phase 2 (Late B/C/D) Single Prime Select Instrument AO Release Instrument Selection PDR/NAR CDR Launch ESA Delta-Studies (NIR) Technology Developments MIR Studies Decision on ESA Contributions Definition Phase (NIR) Phase B (NIR) Phase C/D (NIR) MIR Instrument Development Instrument Delivery

4. ST–ECF UC, Dec 01 4 Current activities ST-ECF contribution in 2001: < 2 FTE including instrument science, s/w engineering and PR Fosbury, Cristiani & Freudling members of ESA Study Science Team Fosbury ex-officio member of ISWG

5. ST–ECF UC, Dec 01 5 Studies Parasitic light in NGST instruments… Cristiani, Arnouts & Fosbury, ISR 2001-01, astro- ph/0106298 Study of slit size optimisation and crowding effects Freudling with Arribas (STScI) “Spoilers” in MEMS-based spectrographs Cristiani, Pirzkal, Freudling et al. Coherence and interference effects in multi- mirror slits: NGST spectral calibration. Freudling et al.

6. ST–ECF UC, Dec 01 6 Future plans ESA intends to contribute to NGST Science Operations. NASA needs to minimise operational costs by using ‘community effort’. ESA, through the ST-DIV, will provide instrument science, data-flow and user support components for the European instrument contributions. It will also carry out PR and educational activities. STScI and ST-ECF are currently discussing how best to distribute this effort.

7. ST–ECF UC, Dec 01 7 Parasitic light effects ‘Uniform’ sky (Zodi or extended continuum source) background flooding the detector with the attenuation produced by the off-MEMS A set of ‘unwanted’ spectra (stars and galaxies) in the FOV, brighter than the target sources but attenuated by the off-MEMS — “SPOILERS” Light scattered from the MEMS structure which does not directly enter the collimator Imperfect filter blocking

8. ST–ECF UC, Dec 01 8 Toy model Direct and dispersed images with spoilers (bright)

9. ST–ECF UC, Dec 01 9 Source sizes Assumed source sizes and their dispersion for the overlap calculations Based on HDF NICMOS data

10. ST–ECF UC, Dec 01 10 Spoiler probabilities Probability of overlap of target source by attenuated bright spoiler with different contrast factors (W Freudling assumptions)

11. ST–ECF UC, Dec 01 11 Range from different authors Exploitable contrast limit set by direct leakage from PSF wings of bright sources

12. ST–ECF UC, Dec 01 12 Simulations Catalogues based on HST observations of HDF-S Simulations performed using selectively attenuated slitless spectroscopy methodology developed for ACS (SLIM, Pirzkal et al.). Sensitivity and performance based on current NGST Mission Simulator

13. ST–ECF UC, Dec 01 13 Simulation parameters R = 1000 12.7h exposure time in 46x1000s integrations Target continuum sources are typical Ly-break at z ~ 3-4 with H AB ~ 24.5-25 Emission line objects are Ly-break with added emission lines corresponding to low metallictiy HII regions scaled to give a Ly  EW of 2000 Å and a typical H AB ~ 26.5-27 FOV is 3'x3' with pixels of 0.1" = 1800x1800 pixels The resulting spectra cover 750 pixels with 16 Å/pixel (constant) in the range 1.2 – 2.4 µm

14. ST–ECF UC, Dec 01 14 Direct image based on NICMOS HDF-S targets targets and spoilers

15. ST–ECF UC, Dec 01 15 Targets no noise Spoilers and targets no noise

16. ST–ECF UC, Dec 01 16 Targets and spoilers with noise Targets with noise

17. ST–ECF UC, Dec 01 17 Targets and spoilers with noise Targets with noise

18. ST–ECF UC, Dec 01 18 Emission targets — 50% of sources have emission Emission targets & spoilers

19. ST–ECF UC, Dec 01 19 Emission with noise Emission and spoilers with noise

20. ST–ECF UC, Dec 01 20 Targets and spoilers with noise Emission targets with noise

21. ST–ECF UC, Dec 01 21 R100 simulations spectra cover 440 pixels with 100Å/pixel in the range 0.6 – 5 µm Typical magnitudes of the candidates H AB ~ 27–28 1/2 of the candidates with very strong emission lines Exposure time is 19.6hr to get a S/N~10 @ H AB ~ 28

22. ST–ECF UC, Dec 01 22 Targets no noise Spoilers and targets no noise

23. ST–ECF UC, Dec 01 23 Targets and noise Spoilers and targets and noise

24. ST–ECF UC, Dec 01 24 MEMS phase errors Study of the throughput (flux calibration) effects produced by phase differences introduced between adjacent MEMS mirrors in the NGST focal plane. Fourier optics methodology (Freudling)

25. OTA & mirror errors

26. Optical layout

27. ST–ECF UC, Dec 01 27 Realisations — 1 Efficiency for randomly chosen mirror parameters The maximum tilt is 0.1°, the maximum offset 0.2µm

28. ST–ECF UC, Dec 01 28 Realisations — 2 Maximum tilt is 0.5°

29. ST–ECF UC, Dec 01 29 Realisations — 3 Randomly chosen position on MEMS ‘slit’ subarray

30. ST–ECF UC, Dec 01 30 MEMS/detector = 2

31. ST–ECF UC, Dec 01 31 MEMS/detector = 1.5

32. ST–ECF UC, Dec 01 32 Array alignment 45° ~0°