We are happy to announce a new survey strategy simulation featuring a new strategy for observing Deep Drilling Fields and request feedback from the community on how well the DDFS perform.
Previously, DDF observations were scheduled as long sequences about once a week. The new ddf_ocean_ocean6_v4.3.5_10yrs simulation now has a mix of short sequences (2 filters, 2 visits each) at nearly daily cadence, in addition to long sequences (129 visits spread over griz) during deep observing seasons with a rough cadence of 1 sequence every 1.5 days. Each of the 5 DDFs has at least one deep season.
The scientific motivation for this mixed strategy is that deep seasons will deliver higher redshift SNe Ia, while shallow seasons with higher cadence will sample shorter timescales for AGN and fast transients. We’ve named the sim “ocean” since it involves deep and shallow sequences of visits.
Some other aspects of the new DDF strategy:
- COSMOS has 3 deep seasons early in the survey
- The Euclid Deep Field South (EDFS) is split into two pointings
- DDF observations are 7.5% of all visits. Our goal is to keep DDFs to 7%. If we go to one-snap visits (rather than the current 2-snaps), we expect DDF visits to come to 7%.
- More frequent DDF observations require slightly more filter changes, slightly reducing the overall efficiency of the survey by ~1%.
- ECDFS, ELIASS1 and XMM-LSS reach 22,000-24,000 visits over all filters. With 3 deep seasons, COSMOS has 48,000 total visits. Each position of EDFS receive 15,000 visits.
- DDF observations in u and y are independently scheduled since these filters are not always in the telescope
DDF-specific analysis for the new strategy and the previous baseline can be found at
https://usdf-maf.slac.stanford.edu/allMetricResults?runId=30
https://usdf-maf.slac.stanford.edu/allMetricResults?runId=5
Full pointing history sqlite files can be downloaded from:
https://usdf-maf.slac.stanford.edu/sims_featureScheduler_runs4.3/baseline/baseline_v4.3.5_10yrs.db
https://usdf-maf.slac.stanford.edu/sims_featureScheduler_runs4.3/ddf_ocean/ddf_ocean_ocean6_v4.3.5_10yrs.db
We welcome feedback on this new DDF strategy and hope to incorporate comments and present a potential DDF strategy at the RCW in July.