Letizia Stanghellini NOAO 16 June 2008 – Science with Giant Telescopes TAC issues Letizia Stanghellini NOAO 16 June 2008 – Science with Giant Telescopes

The NOAO TAC The NOAO TAC system deals with the community access to: The national observatories (KPNO, CTIO) Gemini (international partnership) Public and private partnership observatories NOAO + university partners (e.g., WIYN, SOAR) NOAO public time on Keck, Magellan, MMT, HET via TSIP NOAO TAC science-based; observers request selection of telescopes/instruments offered, based on their science needs TAC Members chosen from the community at large, based on scientific excellence

TAC models Single observatory International partners Multi-partners ESO (one OPC, national partners shares expected to be fulfilled- members selected from member counties) Gemini (national TACs, ITAC to oversee queue/shares/ToO ) Multi-partners Keck, Magellan, WIYN (member TACs, no super-TAC, no general ToO policy except for public access)

TAC models – ground based obs. Partner TACs plus observatory TAC (i.e., super-TAC) Oversight of science policies, control over science time especially ToO Lesser partners are disadvantaged (especially if queue modes are used, since availability of specific weather conditions is limited) Pre-determined shares and partner TACs Limited scientific oversight Partners more likely to get their fair share

Proposal pressure

Distribution of the size of scheduled programs Telescope aperture < 6m (KP, CT, WIYN, SOAR) Telescope aperture > 6m (GEM and TSIP) Note the evolution toward smaller programs

Scheduled programs by team size Over time, the number of large (>5 people) teams is almost invariant for proposals requesting small apertures, while it increases for those requesting large apertures

Joint NASA/NOAO programs