Office of Science U.S. Department of Energy DOE/NSF Review of DES 2 Science (SC1) Andy Albrecht (UC Davis) & Nicholas Suntzeff (Texas A&M) 2.2 Findings and Comments The DES is an ambitious project that will provide significant scientific results on all four of the science projects recommended by the Dark Energy Task Force: supernovae, clusters of galaxies, baryon acoustic oscillations, and weak lensing. The science proposed clearly fits in the Stage III project envisioned by the DETF (both members of the SC1 subcommittee were members of the DETF), both in terms of science goals and exploring systematic errors that will affect the Stage IV experiments.

Office of Science U.S. Department of Energy DOE/NSF Review of DES 2 Science (SC1) 2.2 Findings and Comments (con’t) By combining the results from all four techniques, they have clearly presented a program to improve the FoM by 4.6, well above the recommended factor of three increase for Stage III set out by the DETF. They have presented a convincing case for their approach to detailed study of systematic errors lurking in the data sets, which satisfies the other Stage III DETF requirement. They have incorporated existing large data sets, as well as data challenges into the preparation of the DES science goals.

Office of Science U.S. Department of Energy DETF Recommendations I 2Science (Charge questions 1) Andy Albrecht (UC Davis) & Nicholas Suntzeff (Texas A&M) 2.2Comments

Office of Science U.S. Department of Energy DETF Recommendations II

Office of Science U.S. Department of Energy Comments 2Science (SC1) 2.2Finding and Comments (con’t) Nine recommendations were given by the May 2007 DOE/NSF Review. Specific answers are: A median seeing of 0.8” will be adopted as a goal The DES-FNAL-NSCA-MOU created a process whereby NOAO will use its User’s Committee to allow the US community to make recommendations to the DES science case through NOAO. Competing scientific proposals will be handled by the NOAO TAC, who will receive yearly updates on the scientific progress of the DES. The DES has contacts with the other competing projects to judge the progress of the DES with respect to the other similar science programs underway or being planned.

Office of Science U.S. Department of Energy Comments 2Science (SC1) 2.2Finding and Comments (con’t) A goal of 1% in the photometry has been included, which is required for the SN program. A major effort has been made to create a stronger case for the SN science project. The collaboration with VISTA will greatly help the science case for the SN project, as well as the photo-z’s. The project has formalized 6 science working groups. The DES science data modeling has shown tremendous progress since May The level of error modeling has been greatly increased, and the science cases are mature, except for the SN program. The DES has renewed their emphasis on photometric calibrations.

Office of Science U.S. Department of Energy Recommendations 2Science (SC1) 2.3 Recommendations 1.Finalize the science requirements document within 2 months. 2.Convene the Supernova SWG to review the basic science goals of the supernova case. Rather than “just another SN survey,” special attention should be given to utilizing the unique features of the DES - such as grizYJHK photometry, high accuracy photometry, and tie-in with SDSS-II. Perhaps limits on large scale variations in w can be tested. 3.Create mature observing schedules considering the observing cadences, image quality, and photometric weather goals within 6 months to plan how the time will be divided between the four science cases.

Office of Science U.S. Department of Energy Recommendations 2Science (SC1) 2.3 Recommendations (con’t) 4.Canvas DES partners for other minor science cases to see if they will fit into the DES observing strategies. For instance, TNO discoveries will require a cadence. 5.Consider allowing the detailed observation logs (date, time, filter, exposure time, weather quality, seeing) be available to the US community in real time for the creation of synergistic science.