DDT proposals
The ALMA Observatory is accepting proposals for Director’s Discretionary Time (DDT).
Up to 5% of the observing time in a Cycle can be allocated by the ALMA Director though Director’s Discretionary Time (DDT). DDT proposals must conform to one of the following:
- Proposals of Target-of-Opportunity (ToO) nature that require the immediate observation of an unanticipated, short-lived astronomical event
- Proposals that urgently require ALMA observations that could lead to a breakthrough discovery.
- Proposals of a risky nature that could have a large impact and need a small amount of time to test the feasibility of a program.
Proposal contents
In addition to the normal proposal elements as described in Section 5 of the Cycle 12 ALMA Proposer's Guide, the Scientific Justification of the DDT proposal must include the following:
- A strong justification stating why the project should be considered for DDT allocation.
- A clear justification for why the proposal was not submitted in the most recent Call for Proposals.
Proposal submission
DDT proposals can be submitted using the Observing Tool available through this link. The submission process is done in the same manner as for regular proposals as described in Section 5 of the Cycle 12 ALMA Proposer's Guide. Proposal type “Target of Opportunity” should be selected for proposals falling into DDT category 1 above and type “Regular” should be used for categories 2 and 3. Joint Proposals and Large Programs* cannot be requested through DDT.
*Note that there is currently a bug in the Cycle 12 OT that does not prevent submission of proposals requesting more hours than allowed for a regular proposal (50h). Such proposals are not allowed. The bug has been fixed for the Cycle 12 OT.
Review process
The science assessment of DDT proposals will be based on the same criteria as for Regular and Target of Opportunity proposals (see the Cycle 12 ALMA Proposer's Guide). In addition, the following apply to DDT.
- DDT proposals will be evaluated based on the urgency of the observations and why the proposal cannot wait to be submitted at the next Call for Proposals.
- Proposals that were submitted in the most recent Call for Proposals but not accepted will typically not be accepted for DDT unless exceptionally justified.
- DDT proposals that duplicate observations in the observing queue will be declined without scientific review.
- DDT proposals that duplicate proposals that have been submitted to the annual Call for Proposals and are currently under review will be declined without scientific review.
DDT proposals are reviewed by a standing review committee, with members from the JAO as appointed by the ALMA Director and the four regions, appointed by the Executive Directors and Chile. The ALMA Director will render a decision based on the advice from the standing committee. Decisions are usually announced within 2 weeks of proposal submission. In exceptional cases, the ALMA Director may approve projects that would benefit from a very rapid response and inform the standing committee of this decision within 24 hours.
Proprietary period
For DDT proposals submitted after the start of Cycle 12 on 1 October 2025, there is no proprietary period by default. Data from approved projects will be released to the public immediately after quality assurance is complete.
If a proprietary period of up to six months is required, it must be explicitly requested at the time of proposal submission via a Helpdesk ticket. The ticket should be submitted to the Proprietary Extension Requests Helpdesk department and must include:
- The DDT proposal code,
- The length of the requested proprietary period (up to 6 months),
- A clear justification for the request.
ALMA Observing Tool
The ALMA Observing Tool (OT) is a Java desktop application used for the preparation and submission of ALMA Phase 1 proposals and, for those which are accepted, Phase 2 materials (Scheduling Blocks). It is also used for preparing and submitting Director's Discretionary Time (DDT) proposals. The current Cycle 12 release of the OT is configured for the present capabilities of ALMA as described in the Cycle 12 Call for Proposals. Note that to submit proposals you will have to register with the ALMA Science Portal beforehand.