WINDOWS ON THE UNIVERSE: THE ERA OF MULTI-MESSENGER ASTROPHYSICS | PD 23 5115

Opportunity Information: Apply for PD 23 5115

The National Science Foundation (NSF) funding opportunity "WINDOWS ON THE UNIVERSE: THE ERA OF MULTI-MESSENGER ASTROPHYSICS" (WoU-MMA; Funding Opportunity Number PD 23-5115) supports research that combines multiple ways of observing and understanding the cosmos. The central idea is that modern astrophysics can study the universe through three major "messenger" channels: electromagnetic radiation (light across the spectrum, from radio to gamma rays), high-energy particles (especially neutrinos and cosmic rays), and gravitational waves. Each messenger carries different physical information, and the program is designed to push the field toward projects where these channels are used together in a coordinated, integrated way to reveal phenomena that cannot be fully understood through any single window alone.

The program's main goal is to build capability and accelerate synergy between observation and theory so the community can carry out truly multi-messenger investigations. WoU-MMA is looking for projects that strengthen the links between facilities, datasets, models, and research teams spanning these three domains. Competitive projects are expected to help move the field forward beyond what would happen through separate, parallel efforts in electromagnetic astronomy, particle astrophysics, or gravitational-wave science. The solicitation emphasizes that this builds on momentum and community infrastructure developed during the program's initial five-year period, with an eye toward deepening interoperability across instruments, analysis approaches, and scientific collaborations.

NSF highlights three broad categories of activities that fit the WoU-MMA scope, and a proposal should clearly align with at least one of them. First are Coordination Activities, which focus on organizing and enabling observations that involve more than one messenger. This can include networks, protocols, scheduling or alert coordination, shared pipelines, joint observing campaigns, and other mechanisms that make cross-messenger follow-up more effective and faster. Second are Observations, meaning observational projects targeting objects or events that are plausible sources of multiple messengers, such as compact object mergers, core-collapse supernovae, active galactic nuclei, or other energetic transients and extreme environments. Third is Interpretation, which covers theory, simulations, experiments, data analysis methods, and related efforts aimed at explaining or extracting physical meaning from multi-messenger observations, including modeling source populations, emission mechanisms, and the connection between signals in different channels.

A key point in the solicitation is that WoU-MMA is not meant to replace NSF's existing programs that already fund work within any one messenger area. Instead, it is intended to support awards with substantial multi-messenger components, where the cross-cutting integration is central rather than incidental. Priority is given to proposals that represent dedicated efforts likely to make a significant difference in achieving WoU-MMA goals, rather than projects that only lightly touch on multi-messenger connections. The program also encourages efforts that integrate historically separate research communities, improve full interoperability between the three windows (including shared standards, tools, and coordinated workflows), and help develop a skilled workforce trained to operate at the boundaries between these areas.

From an administrative and submission standpoint, proposals are submitted through relevant participating NSF programs rather than to a single standalone WoU-MMA program office. The opportunity is tied to multiple NSF divisions and programs, including areas such as Astronomy and Astrophysics Research Grants and Postdoctoral Fellowships, Advanced Technologies and Instrumentation, Particle Astrophysics (experiment) and Particle Astrophysics and Cosmology (theory), Nuclear Physics (theory and experiment), Gravitational Physics (theory), LIGO Research Support, and Plasma Physics. Investigators who want their proposal considered specifically under WoU-MMA must signal that intent by beginning the proposal title with the acronym "WoU-MMA" and should only do so if the project clearly meets at least one of the stated criteria. If a proposal is labeled for WoU-MMA consideration but does not actually address the required criteria, it will be reviewed only within the underlying NSF program to which it was submitted. The solicitation also notes that supplement requests to existing awards can be considered, as long as the supplemental work aligns with the WoU-MMA criteria.

In terms of basic opportunity details, this is a discretionary NSF grant opportunity in the Science and Technology and other Research and Development category, with CFDA numbers 47.049 and 47.050. Eligibility is listed as unrestricted, meaning it is broadly open to applicant types, subject to any clarifications in the full solicitation text. The opportunity was created on August 19, 2023, with an original closing date of October 16, 2023. The listing shows an expected number of awards around 200, while the award ceiling is shown as 0, which typically indicates that a fixed cap is not specified in the summary record and applicants need to refer to the relevant program guidance and typical award sizes in the associated NSF programs.

Overall, WoU-MMA is best understood as an NSF-wide push to fund projects where the scientific payoff depends on combining electromagnetic observations, high-energy particle measurements, and gravitational-wave detections, along with the theory and infrastructure needed to unify them. Proposals that stand out will usually make a strong case that multi-messenger integration is essential to the research plan, that coordination or interoperability challenges are being concretely addressed, and that the work will leave the community better able to carry out rapid, rigorous, and interpretable multi-messenger science in the coming years.

• The National Science Foundation in the science and technology and other research and development sector is offering a public funding opportunity titled "WINDOWS ON THE UNIVERSE: THE ERA OF MULTI-MESSENGER ASTROPHYSICS" and is now available to receive applicants.
• Interested and eligible applicants and submit their applications by referencing the CFDA number(s): 47.049, 47.050.
• This funding opportunity was created on Aug 19, 2023.
• Applicants must submit their applications by Oct 16, 2023 Astronomy and Astrophysics Postdoctoral Fellowships Astronomy and Astrophysics Research Grants Advanced Technologies and Instrumentation Nuclear Physics - Theory and Experiment Particle Astrophysics - Experiment Particle Astrophysics and Cosmology - Theory Gravitational Physics - Theory LIGO Research Support Plasma Physics Plasma Physics Plasma Physics Gravitational Physics - Theory LIGO Research Support Particle Astrophysics - Experiment Astronomy and Astrophysics Postdoctoral Fellowships Astronomy and Astrophysics Research Grants Nuclear Physics - Theory and Experiment Particle Astrophysics and Cosmology - Theory. (Agency may still review applications by suitable applicants for the remaining/unused allocated funding in 2026.)
• The number of recipients for this funding is limited to 200 candidate(s).
• Eligible applicants include: Unrestricted (i.e., open to any type of entity above), subject to any clarification in text field entitled Additional Information on Eligibility.

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