I keep losing the links to the deep drilling white papers that were submitted by each of the science collaborations in 2011, and that played a significant role in shaping the current deep drilling strategy in Opsim.
I also find that other people can’t find these white papers.
The link is here!
There was a series of pages on the (long languishing but still online) science wiki:
but this material should be moved somewhere publicly viewable.
A synthesis of the requests from these DD proposals comes down basically to:
5 ‘extragalactic’ fields (most likely the 4 extragalactic fields ELAIS S1, XMM-LSS, Extended Chandra Deep Field-South, and COSMOS, along with 1 more undecided pointing) observed as follows:
265 sequences (on different nights) of 20 g exposures, 40 r exposures, 40 i exposures, 52 z exposures and 40 y exposures (~68 minutes per sequence), spread over 10 years. This corresponds roughly to observations taken every 3-4 nights, if the ‘observing season’ is assumed to be 4 months long for each field.+
185 sequences of 40 u band exposures, spread over 10 years. (no time constraints relative to grizy observations).
This would achieve final coadded limiting magnitudes of approximately u=28.5, g=28.7, r=28.9, i=28.4, z=28.0, and y4=27.0 (with varying single-night depths depending on lunar cycle, ranging from approximately g=26.2-24.4, r=26.1-25.1, i=25.6-25.1, z=25-24.8, y=24.1-24.0).
These fields require about 335 hours per field in real-time observing.
Observations take place over all 10 years of the survey, and require 1675 hours total (all 5 fields).
+[Note camera limitation of 5 filters at a time; during the time around new moon the u band filter will be in the camera and the grizy sequence will be somewhat interrupted.]
5 (different) extragalactic fields (unchosen but with high ecliptic latitude, high galactic latitude, low extinction, and no foreground clusters) observed as follows:
265 sequences (on different nights) of 20 g exposures, 40 r exposures, 40 i exposures, 52 z exposures and 40 y exposures (~68 minutes per sequence), spread over 10 years, as above.
57 sequences of 40 u band exposures, spread over 10 years.
This would achieve final coadded limiting magnitudes of ~ u=28.0, g=28.7, r=28.9, i=28.4, z=28.0, and y4=27.0 (similar single night depths to other 5 extragalactic fields).
These fields require about 309.4 hours per field in real-time observing.
Observations take place over all 10 years of the survey, and require 1547 hrs total (all 5 fields).
3 Milky Way/Local Volume fields (South galactic pole & Blanco 1 (RA 00:53, Dec -26:33), Galactic anticenter (RA 04:02, Dec 11:01), and one of three proposed open clusters (11:05, -58:44; 08:03, -28:01; 17:25, -49:58), observed as follows:
30 sequences (on consecutive nights), consisting of 3 subsequences of [2 y exposures, 2 i exposures, 2 z exposures], subsequences separated by ~30min-1hrs (this set of exposures takes place once per field for 30 days).
133 sequences of 30 g exposures, 2 r exposures, 70 i exposures (within 1 week of new moon), spread over 2.5 years
113 sequences of 70 i exposures, spread over 2.5 years.
This would reach final coadded depths of ~ g=29, i=28.9, r=27, z=25.6, y4=24.9. (although in z and y, the individual image depths are the relevant parameters and are equivalent to the main survey).
These fields require about 135.8 hrs per field in real-time observing.
Observations take place over ~2.5 years per field, but fields could be spread over 10 years of survey if needed, and require 407.3 hrs total (all 3 fields).
6 Transients/Variable stars fields (4 pointings toward LMC, 1 at SMC & 47 Tuc, 1 at IC 4651) observed as follows:
1 hour of continuous g band exposures
sequences of [2 g exposures, 2 r exposures] spread over next 3 nights at various time intervals, for 7 hours of total real-time exposures
Within the next few months -
1 hour of continuous r band exposures
followed by sequences of [2 g exposures, 2 r exposures] spread over next 3 nights for 7 hours of total real-time
The pattern should be repeated again at a later time for period validation. All observations should occur within 1 week of new moon.
This would reach coadded depths of ~ g=28.3, r=28.1 after all 4 3-night cycles, although the individual exposure depths are similar to the main survey (and are the relevant quantity for most of the transient/variable phenomena).
These fields require about 32 hours real-time per field.
Observations take place over ~1 year for each field, but fields could be spread over 10 years of survey if needed, and require 192 hrs total (all 6 fields).
9 solar system fields (9 pointings in a 3x3 grid centered on 19:35:04, -21:38:32 where Jupiter and Neptune Trojans will coincide, in year 2022), observed as follows:
8 sequences of 283 exposures in r band (continuous) on different nights, epochs specified as 2 nights 1.5 months before opposition, 2 nights at opposition, 2 nights 1.5 months after opposition, and 2 nights 1 year later (approximate timing). Each of the ‘2 night’ sets should be consecutive or at most a few nights apart. (Total of 8 epochs of observations, with 283 exp in each epoch).
This would reach a total coadded depth of ~r=28.1, with each individual night being coadded to ~ r=27.0 (which is the relevant quantity for the solar system detections).
These fields require about 11.3 hours real-time per field.
Observations take place over 1 year, and require 101.7 hrs total (all 9 fields).
The combination of the above produces an oversubscription rate of about 2 compared to then-current time invested in DD (in opsim 3.61). The total time required above is 3923 hours, and the time currently programmed as DDF’s in Opsim 3.61 is about 1972.5 hours. It also gives us about 28 various deep drilling pointings to satisfy all the science requirements, although not all of these have similar observational sequences.