Telescope Access Metrics Presentation to NOAO Users Committee October 12, 2004

Ground rules Categorize telescopes as Large: 6.5m or greater Gemini, others with TSIP (FIP) access Medium: 3-4.2m Mayall, Blanco, WIYN, SOAR Small: 0.9-2.1m KP 2.1m, WIYN 0.9m, SMARTS Count nights available for science for past semesters Extrapolate for future semesters Gemini ramps up to 60 U.S. nights/telescope/semester Currently averages ~50 SOAR begins science observations in 2005B and ramps up over 1 year

Precommitments-Surveys Note that surveys are subject to the same peer review as regular proposals 20% cap Proposals only taken once per year Program started in 1999; none solicited in 2003 or 2004 Surveys can run up to 5 years Actual nights committed run 10-20% for both medium and small telescopes No surveys have been granted on large telescopes

Precommitments - NASA Agreements with HST, Chandra, Spitzer Up to 5% of NOAO time available for complementary (not follow-up) ground-based observations connected with successful proposals Proposals go through NASA peer review and NOAO technical review Actual nights committed typically are 5-15 per semester on all telescopes << 15% maximum

Precommitments – instrument partnerships Aimed at providing new instrumental capabilities on NOAO telescopes for guaranteed time U Maryland agreement: 20% of Mayall time Exchangable for WIYN or 2.1m U. Md contribution (cash plus manpower) for NEWFIRM Flamingos: base (4m: 3n, 2.1m: 5n) plus 4-6n for every 14 nights (after first 14) allocated to community GSFC IRMOS: draft MOU – 4-5 n per semester on 4m, 8-10 n per semester on 2.1m, Ge Exoplanet Tracker: draft MOU – 21 n per semester on 2.1m All “guaranteed time proposals” go through TAC If they do not succeed (which is rare), they are deferred to a later semester so the proposal can be improved

Current tally 2002 2003 2004 2005 2006 2007 Large-total Precommit remaining 146 201 253 265 263 278 Medium-total 739 207 532 698 166 654 168 486 714 132 582 774 47 727 786 Small-total 1071 186 885 633 141 492 653 119 534 640 29 611 12 628

Reasonable predictions TSIP will continue to add 25-30 large telescope-nights per year TSIP will also add 30-60 medium telescope-nights per year The survey program will resume in 2005, leading to a future level of precommitment about the same as the past The NASA precommitments will continue at a level of a few nights per semester PREST will add approximately 200 nights of small telescope time per year

Tally with reasonable predictions 2002 2003 2004 2005 2006 2007 Large-total Precommit remaining 146 201 253 277 290 305 Medium-total 739 207 532 698 166 654 168 486 744 170 574 834 664 846 676 Small-total 1071 186 885 633 141 492 653 119 534 690 140 550 740 600 840 700

Nights remaining with predictions

Oversubscription rates Nights requested divided by nights available after precommitment Even with devolution of small telescopes, access is reasonable Survey proposals (not included in graph) run 4.5-5.5 for medium telescopes; 1.5-2.5 for small telescopes

Conclusions All oversubscription rates are in healthy range – and increase with increasing aperture Status quo results in reasonable access TSIP and PREST are expected to improve the situation – particularly for medium and small telescopes Large telescope access is limited by willingness of independent observatories to give up more nights (TSIP) and by our fraction of Gemini.