Proposing observations with ALMA

Call for proposals of ALMA is generally issued on an annual basis, with the submission deadline in spring. Information on observing capabilities in the next cycle is made public in the pre-announcement normally released in winter, and this information can be used to start the proposal planning. At the opening of the Call for Proposals, the necessary tool (Observing Tool) and documentation will be made available. Please carefully read the Proposer's Guide and other documents if you are going to propose observations with ALMA.

Official documents and other information related to the proposals

Please refer to the documents on the ALMA Science Portal for official information.

Supplemental Information

Most recent CfP

Cycle 11 Call for Proposals is now closed (the deadline: 15:00 UT on Thursday 25 April 2024).

New observing modes

The following modes will be offered in Cycle 11:
  • Full polarization in Band 1 on the 12-m Array. The polarization accuracy and capability will be the same as in Bands 3-7.
  • Band 1 on the 7-m Array for Stokes I only (no Stokes Q/U/V).
  • High-frequency and long-baseline observations with Band 9 in C-10 configuration, and Band 10 in configurations of C-9 and C-10.
  • 4x4-bit spectral mode on the 7-m Array (dual polarization). The 4x4 mode is available for the 7-m Array and allows spectral setups that are fully compatible with those of the 12-m Array.


FAQ and notes for proposal preparations

Here are some items based on the questions frequently asked during proposal submission, as well as some notes that should be keep in mind. Please see the next section in this page regarding the general suggestsions for preparing ALMA proposals.
Similar proposals from the same science team are discouraged
ALMA encourages the scientific diversity of proposals. However, the submission by the same science team of multiple proposals with very similar high level science goals but otherwise minor differences is discouraged; such proposals should be combined where practical. In recent cycles, an increase in the number of such proposals has been detected. ALMA will monitor this trend and may consider policy changes in future if the trend continues.
Font size in Scientific Justifications
Scientific Justifications, including figure captions and reference lists, should be in a font size of 12 points or larger. If the Observing Tool checks the font size and finds that 15% or more of the total font size is smaller than 12 points, you will see an error message in the OT and cannot submit your proposal. Sometimes the error is due to a small font embedded in a PDF figure, not in the text. If this is the case, you can work around the problem by putting the figure in a different format (e.g., jpeg) (link to Knowledgebase article on font size). See also the section of "Page limits and fonts" in the Proposer's Guide for more information.
Updating your user profile in the Science Portal
If your affiliation and/or email address has changed, please update your user profile information in the Science Portal. Please make sure that you never submit proposals with the incorrect affiliation.
Also, proposals except for Large Programs will be reviewed in the distributed peer review system. In this review system, one member of the proposal team on each submitted proposal will be responsible for reviewing other proposals. The keywords in the "Expertise" in the Science Portal user profile is relevant to the assignmnet of proposals for review. Therefore, please make sure to enter/update your "Expertise" information (You can move to the Expertise tab by clicking on the "Next" button. After the edits, please go to the Confirm tab and Update.).
Double-anonymous review
Proposal review will be conducted in a dual-anonymous manner to reduce bias against the proposer as much as possible and to focus on evaluating the science. The reviewers do not know who propose the observations, and the proposers do not know who review their proposals. The Science Justification must also be written in such a way that the identity of the PI cannot be determined. For guidelines on how to write the justification, please refer to this page.
Total Power (TP) only observations
Total Power (TP) only observations can be requested only if the PI has existing 7-m Array data. More details can be found in Section A.3 of the Proposer’s Guide.
Director’s Discretionary Time (DDT) Project
Proposing for DDT observations in the on-going cycle is possible at any time. Proposals that were previously submitted for that cycle but not accepted will typically not be considered for DDT. Approved DDT programs are in the observing queue for 12 months after the proposal acceptance. Please visit here for more information on DDT proposals.


Suggestions for preparing ALMA proposals from scheduling and Phase 2 generation viewpoints

Once a project has been approved for scheduling, the project passes into Phase 2. ALMA staff will generate the Scheduling Blocks (SBs) for all approved projects and submit the SBs to the observing queue. To maximize chances of observing your projects to meet the scientific goals and prevent potential issues during Phase 2, PIs are encouraged to consider the following suggestions while preparing the proposals. If there are any questions, please don't hesitate to contact us via Helpdesk (https://help.almascience.org/).
Request multiple configurations or a broader range of Desired Angular Resolution to improve chances of having a SB observed
  • When the range of angular resolution (instead of a single value) is acceptable for the science goals, PIs are encouraged to enter a range of Desired Angular Resolution spanning more than one configuration. The possible configurations can be found via the "Planning and Time Estimate" button in the ALMA OT "Control and Performance" panel.
  • As mentioned in Section of "Angular resolution" of the Proposer's Guide, for scheduling feasibility and Quality Assurance (QA) purposes, if the PI selects a single value for the Desired Angular Resolution or a range narrower than 20% around its center value, a range of +/-20% around the single or center value specified will be enforced. Therefore, whenever feasible and scientifically acceptable, PIs are encouraged to enter a range broader than 20% around its center value. For example, request the Desired Angular Resolution in the 1.8-3.2 arcsec range instead of 2.3-2.7 arcsec range if scientifically acceptable. The latter will be enforced to 2.0-3.0 arcsec after applying the rule mentioned above.
Please note that if the requested range includes both long-baseline and more compact configurations, only the latter will be considered in the OT. An exception is constituted by ToO observations that can be triggered in any configuration if the angular resolution requested by the PI is "any".
For 12-m Array observations in higher frequency, try to select science targets that can be observed during the LST range given in Table 3 of the Proposer's Guide
Weather conditions also play a role in scheduling observations. The amount of time with stable atmospheric conditions suitable for Bands 7 and 8 observations outside of the LST ranges in Table 3 of the Proposer's Guide is limited. Bands 9 and 10 observations will be scheduled during the LST ranges in Table 3 (see the section of "Configuration schedule for the 12-m Array" in the Proposer's Guide). Therefore, to increase chances of having Bands 7 to 10 observations with 12-m Array, PIs are encouraged to select science targets that can be observed during the LST range given in Table 3.
Prevent spectral windows (spw) lie close to the baseband edge
Any spw lies within 30 MHz of the baseband edge could result in compromised flux calibration and might also cause problems of finding the tuning solution for Local Oscillator signals. In the worst-case scenario, the PI might need to sacrifice one or more spws during observations. To prevent these issues, OT will throw a warning message to remind PIs to move the spw away from the baseband edge after PIs validate their proposals. PIs are encouraged to resolve such warning messages before submitting their proposals.
For a multiple-visit observation, set all visits relative to the first visit
If the PI designs a multiple-visit observation to monitor a source in a Science Goal, whenever feasible to achieve the science goals, it is recommended to set all visits relative to the first visit. Otherwise, if any of the visits is not observed, the following visits might be missing as well.
Changes after the acceptance is not easy
PIs should carefully check observational setup before submitting the proposals. Major changes are allowed only if additional information that may seriously affect the scientific case of the project has become available since the time of submission, when there is a demonstrable mistake, or when there is the potential for interesting scientific optimization. For example, without substantive justification based on additional information (other than information already provided in the proposals), changing the Desired Angular Resolution simply to increase chances of executing a SB would most likely be declined. See more details in the section of "Changes to submitted programs" of the Proposer's Guide.

Other links



Last Update: 2024.5.1