Are there policies specific to Large Programs?
Posted by Sarah Wood, Last modified by Kazuya Saigo on 02 March 2020 09:33 AM
According to the Large Programmes section of the ALMA Proposers Guide
Large Programs are proposals with an estimated execution time of greater than 50 hours on the 12-m Array (with or without accompanying ACA time) or 150 hours on the 7-m Array in stand-alone mode. Large Programs should not involve time-critical or ToO observations, and may not involve full polarization measurements, Solar observations, VLBI, pulsar mode, or Astrometric observations.
Clarification:The fraction of time in a configuration that can be allocated to Large Programs is constrained to make it likely that observations can be completed within one Cycle. The JAO will report on the scheduling feasibility of Large Programs to the APRC.
Proposal teams will need the following information to assess the scheduling feasibility of their program:
Examples: Estimating scheduling feasibility for Large Program.
A proposal team wants to survey a sample of 30 protostars at 0.06” resolution in Band 7. The protostars are located at a right ascension of 5 hours and declination of -20 deg. The ALMA Observing Tool indicates that the observations, including all calibrations, can be completed with 45 hours of time in configuration C-7 (see also Table A-1 in the Proposer’s Guide). Since the sources are at declination of -20 deg, the observations will take place +/- 3 h around transit, or between 2 h and 8 h LST.
For this example, assume that the time available for science observations in C-7 between an LST of 2 and 8 h is 96 hours. PIs should check the Proposer’s Guide for the actual time available. The time available for Large Programs in C-7 over this LST range is then 48 h (i.e., half the available time).
PIs also need to check the amount of time available for Band 7 observations. If configuration C-7 is scheduled for October, the LST range with the best conditions will be between LST of 13 h and 3 h. Since the required sources can be observed 23 and 11 LST, they will be observed in the period with generally stable weather conditions (i.e., night time). The weather conditions in October for C-7 at night are expected to be suitable for Band 7 observations 60% of the time. Therefore configuration C-7 will have ~ 96 * 0.6 = 57 h available for Band 7 observations.
Since the requested time in C-7 (45 h in Band 7) is less than the time available for Large Programs (48 h) and less than the time expected for Band 7 weather (57 h), the Large Program is considered feasible.
On the other hand, if the proposal requested 60 h of Band 7 time in C43-7, it would exceed the time available for Large Programs and the time suitable for Band 7. The proposed Large Program would then be judged to be at risk to be completed during the Cycle. The proposal team could reduce the risk by requesting a range of angular resolutions (e.g, 0.06-0.2”) so that the observations can be spread between C-7 and C-5.
Proposals teams of Large Programs are encouraged to discuss the scheduling feasibility in the Scientific Justification.
The Large programmes section of the ALMA Proposers Guide states:
b) The proposal team wants to observe one of the galaxies in the Large Program in CO J=1-0, but with three times better sensitivity than requested in the Large Program. These observations do not duplicate observations in the Large Program according to the ALMA Duplication Policy and are therefore a Regular Proposal is allowed.