1. Michigan/MIKE Fiber System (MMFS) – Update Apr 2005

2. On Telescope: 27 science nights since start 2004A 2 dedicated engineering nights Installation: Process now well documented; takes 3-4 hrs plus overheads (MMFS to MIKE tricky in 1 day) -- Remove MIKE/guider/baffles on Clay -- Install MMFS -- Remove MIKE optics/rotate CCDs on MIKE -- Replace MIKE on platform -- Install MMFS fiber shoes into MIKE -- Prepare for observing (blocking filter, grating tilts, etc.) -- Focus, calibration, data, observe Still require a full web-based documentation of process.

3. Issues -- Fiber tips still fail about 1 per night; easy to repair. -- Blue CCD developed high dark counts starting in Oct 2004 (acceptable), through Dec/Jan 2004/05 (unacceptable, loss of nights), Feb 2005 (even worse one lost night). -- High dark with odd, quasi-concentric pattern -- Visible pattern of contamination on CCD with same pattern. -- IT suggested O 2 + heat flood; this solved the problem.

4. 2400 sec image Dark rate ~ 0.5 e/sec/pix

5. -- Very few spare fibers; more needed. -- More blocking filters to isolate more individual orders (Ca IR triplet; H-alpha; Mg complex) -- Arc control system was flaky (inconsistent operating voltage on HV lamps). New system installed based on MOE controller/GUI and MMFS lamp support system on the secondary.

6. Operations Efficiencies: For dSph kinematic studies we can compare. [1-2 km/s to V=20.5-21.0 red giants] VLT – 10 stars per hr (+ high res spectra) MMT – 8 stars per hr (based on recent run; some light leak problems that should be fixed soon). MMFS – 25 stars per hour Includes all overheads, standards, etc. Explicit overheads: 20-45 min for fiber changes 5 min per velocity of abund standard 2 min per arc

7. MMFS: Data Sculptor red giants 5130-5190 A (Mg complex) V = 20.5-19.0 ET = 2.5 hours

8. 1991, 1992, 1993, 1994, 2002 Samples are substantially bigger:

9. 1991, 1992, 1993, 1994, 2002 3 hours in October 2004 And growing rapidly:

10. Carina red giant R ~ 18000 V ~ 19.6 CCF precision ~ 1 km/s Velocity errors can be managed (14% repeat observations), even in faint, metal-poor stars.... The dispersion is sensitive to excess velocity errors only when these errors become large compared to the dSph’s overall dispersion... (Kleyna et al. 2005, regarding the history of Sextans velocity error estimates).

11. Galaxy N targ N obs M V Sculptor 3200 1068 +0.5 Fornax 5000 560 -0.7 Carina 1600 1560 +0.0 Leo I 1500 -- -1.5 Sextans 2200 1190 +0.3 Draco 1200 -- +1.0 MMFS/Hectochelle: dSph Status Report Total = 4300 different stars observed so far; 700 repeats. For comparison: 450 total in Mateo 1998 summary. Will hear more from WHT, VLT, Keck at this meeting...

12. User concerns -- Learning curve for MMFS operations is steep. May require a `fiber operator’ who is employed only for MMFS runs and paid for by users as part of the cost of plates and plate fabrication. Need to coord- inate with LCO/Magellan staff. -- Plate fabrication requires good coordinates from users; all software for plate fabrication are operating and well-tested. -- Fiber assignment is still primitive; hope to improve this in anticipation of 2005B observations.