Chandra Legacy Program

Rodolfo Montez Jr.

In November 2023 the CXC issued the Chandra Legacy Program (CLP) call for white papers to identify science challenges for which the capabilities of Chandra are absolutely required. These science programs were to be designed to address fundamental questions about our current understanding of the components and evolution of the Universe.

The community of Chandra users submitted twenty-two white papers, covering a broad range of scientific topics spanning nearby stellar nurseries to distant galaxy clusters. The white papers honed in on some of Chandra’s unique capabilities—from low-background, high-resolution imaging to high-resolution grating spectroscopy—and demonstrated how those capabilities were well-suited to expand our understanding of the Universe.

A committee of seven external (non-CXC) members of the astrophysics community had the difficult task of reviewing the twenty-two white papers over a week-long review. After the CLP Review Committee completed its evaluation of the white papers, recommendations for major science themes were presented and became the following two initiatives for a Call for Legacy Proposals:

Initiative I: Probing the Physics of Baryon Cycles and Feedback using Deep Observations of Nearby Galaxies

Initiative II: Deep Observation of a Galaxy Cluster to Understand Key Physical Processes

Following a call for proposals, two review panels were constructed, one for each initiative, composed of topical experts from the astrophysical community. The proposals were evaluated along several metrics, including their scientific merit, use of Chandra capabilities, legacy impact, and alignment with the initiative. The review committees provided their recommendations to CXC director Pat Slane, and the following programs were selected:

For Initiative I:

A Treasury Survey Probing the Baryon & Energy Cycle and X-ray Binary Evolution in Galaxies at High Angular Resolution (PI: Smita Mathur) with an award of 2.9 Ms.

For Initiative II:

The Sounds of Feedback: Deep and Wide Imaging of the Cool Core of the Perseus Cluster (PI: Andrew Fabian) with an award of 3.0 Ms.

The programs will run in parallel over the course of Cycles 26 and 27, which nominally begin in January 2025 and January 2026, respectively.

For more information about the selected programs, please visit the CLP website, where you can find the full proposal abstracts.