Science Analysis Group
High Angular Resolution X-ray Imager
The High Angular Resolution X-ray Imager SAG will address the scientific opportunities enabled by ultra-high angular resolution X-ray imaging across broad scientific categories. Hi-ReX SAG membership is open to the astrophysics and technology communities.
About Hi-ReX SAG
Scientific Analysis for an Ultra-High Angular Resolution X-ray Imager Observatory
Recent advances in X-ray optics, precision formation flying, and high-resolution detectors have made it feasible to pursue milli- to micro-arcsecond (mas to μas) imaging in the X-ray band. Such capability would exceed Chandra’s angular resolution by more than two orders of magnitude and could enable transformative discoveries across a broad spectrum of high-energy astrophysics.
The High Angular Resolution X-ray (Hi-ReX) Imager Science Analysis Group (SAG) will assess the scientific potential of a future flagship-class or probe-class mission with mas to μas imaging resolution, identifying key science drivers, performance requirements, and initial technical considerations, while remaining focused on science. This effort will build on previous and current conceptual studies and recent progress in optics and lens designs.
Modern astronomers are also interested in studying the SMC (and its cousin, the Large Magellanic Cloud), but for very different reasons. Because the SMC is so close and bright, it offers an opportunity to study phenomena that are difficult to examine in more distant galaxies. New Chandra data of the SMC have provided one such discovery: the first detection of X-ray emission from young stars, with masses similar to our Sun, outside our Milky Way galaxy.
The new Chandra observations of these low-mass stars were made of the region known as the "Wing" of the SMC. In this composite image of the Wing, the Chandra data are shown in purple, optical data from the Hubble Space Telescope are shown in red, green, and blue, and infrared data from the Spitzer Space Telescope are shown in red. The combined X-ray, optical, and infrared data also revealed, for the first time outside our galaxy, objects representative of an even younger stage of evolution of a star. These so-called "young stellar objects" have ages of a few thousand years and are still embedded in the pillar of dust and gas from which stars form, as in the famous "Pillars of Creation" of the Eagle Nebula.
This SAG will address the scientific opportunities enabled by ultra-high angular resolution X-ray imaging across broad scientific categories such as:
- Exoplanet Habitability and Exoplanet Host Stars, such as imaging of stellar coronae and flares of exoplanet host stars;
- Star Formation and Evolution, including mapping proto-stellar disks and interacting binary systems;
- Galactic Astrophysics enabled by high-resolution studies of pulsar wind nebulae, relativistic accretion flows and outflows, and shock fronts;
- Extragalactic and Black Hole Physics that can be probed by imaging the immediate surroundings of supermassive black holes to complement recent advancements with the Event Horizon Telescope; and
- Fundamental Physics and Cosmology, such as testing general relativity near event horizons via direct imaging and reverberation mapping.
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Hi-ReX SAG Chairs
| Name | Institution |
|---|---|
| Kimberly Weaver | NASA Goddard Space Flight Center |
| Herman Marshall | MIT Kavli Institute |
| Mark Schattenburg | MIT Kavli Institute |
| Breanna Binder | Cal Poly Pomona |
The SAG will organize its work into scientific thematic working groups (WGs) tasked with identifying technical capabilities (including but not limited to energy bandpass, imaging resolution, field of view, throughput, effective area, etc.) required to achieve significant progress in the “state of the art” scientific understanding of each thematic area.
The final deliverable will be a community-vetted report to NASA HQ in June 2026 detailing the science case, technical drivers, and recommendations for future studies of an ultra-high angular resolution X-ray mission.
News & Events
Meetings, conferences, seminars, workshops, and other news and events for Hi ReX SAG
Hi-ReX SAG will have a kick-off meeting next week on Wednesday, December 17, at 12pm EST (9am PST).
This SAG will address the scientific opportunities enabled by ultra-high angular resolution X-ray imaging across broad scientific categories such as: Subscribe to the Hi-ReX SAG Email List To join the list, send an email to Hi-ReX-SAG-join@lists.nasa.gov with Subject=”join” To unsubscribe, Send…
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