Science Highlight




Supplemental Call for Proposals to use the 7-m Array in Cycle 4

The ALMA Director announces that the Joint ALMA Observatory (JAO) will accept observing proposals that request to use the 7-m Array in the remainder of Cycle 4, which ends on September 30, 2017. This proposal call enables the community to propose projects that will fill in undersubscribed regions of the observing queue for the 7-m Array. Up to 800 hours on the 7-m Array will be allocated through this opportunity.


Proposals must be compatible with the capabilities listed in the ALMA Cycle 4 Call for Proposals, with the following restrictions:

  1. Proposals for this special call will be accepted only for the 7-m Array in stand-alone mode. Proposals that request the Total Power (TP) Array or the 12-m Array will be declined.
  2. A proposal may request up to 50 hours of observing time on the 7-m Array. We encourage large time requests within this limit.
  3. Proposals will be accepted in Bands 3, 4, 6, and 7 for any LST, except between LST of 15 h and 20 h in Bands 6 and 7. The largest amount of time available in any band is at an LST of > 22 h and < 13 h.
  4. Only proposals that request standard modes are permitted, as defined in the ALMA Cycle 4 Proposer’s Guide.


Proposals can be submitted starting April 21, 2017 and will be reviewed as they are received. Instructions on how to submit a proposal through the ALMA Observing Tool (OT) will be made available on the ALMA Science Portal on April 21. Proposals can be submitted at any time up until the end of Cycle 4 or until the available time has been fully allocated. An announcement will be posted on the ALMA Science Portal when this opportunity closes. 

Proposals will be reviewed by a committee that consists of representatives from the JAO, the ALMA Regional Centers (ARCs), and Chile. The primary criterion in assessing the proposals is the overall scientific merit of the proposed observations. The committee will forward their scientific assessment to the ALMA Director, who will make the decision on whether the proposal shall be scheduled. Review decisions should be announced to the proposal team within 2 to 4 weeks after proposal submission. 

All proposals accepted through this proposal call will receive a Grade C and will be assigned lower priority than the remaining projects in the 7-m Array queue. The proposals will not be carried forward to the next cycle if the observations are not completed during Cycle 4.

The data will be quality assessed by ALMA staff before being delivered to the Principal Investigator (PI) or their designee. Data will be considered to have passed the quality assessment if the requested on-source integration time has been achieved, as long as no significant technical problems are found during data reduction. 

PIs are reminded that since the 7-m Array observations will be obtained with ~10 antennas, the instantaneous uv coverage is limited. Therefore, the 7-m Array should not be used for snapshot surveys of complex sources. Also, the 7-m Array can be shadowed below 55 degrees elevation, with ~2 antennas shadowed when the elevation drops to 45 degrees. This affects the effective number of antennas at extreme north and south declinations and may be a consideration for projects requiring lengthy integration. Proposals should justify any observations affected by these constraints.

PIs may submit a 7-m Array proposal in response to this call that duplicates their Cycle 5 proposal, in which case the Cycle 5 proposal will be treated as a resubmission. If the Cycle 4 proposal is approved and completed, the corresponding Cycle 5 Science Goals will be descoped.