The STAR-X Science Story
Exploring the Fast, Furious, and Forming Universe
The FAST: Locally rare, brief events have an outsized impact on the Universe.
The heavy elements needed for life are synthesized in and dispersed by supernovae and neutron star mergers. Similarly, a single stellar superflare can evaporate an ocean or catalyze prebiotic pathways. The STAR-X wide field UV/X-ray design and fast and flexible operations captures these events.
The FURIOUS: Black holes grow extremely rapidly at early times in the Universe and are critical to galaxy evolution.
STAR-X will uniquely probe the physics of rapid accretion that allowed massive black holes to grow so quickly in the early Universe. STAR-X will catch transient, extreme black hole feeding events, such as TDEs, where entire stars are disrupted.
The FORMING: Distant galaxy clusters provide maximal leverage in evolutionary studies of structure formation and chemical enrichment.
STAR-X will conduct deep surveys and discover the elusive diffuse emission from the largest bound objects in the Universe (clusters of galaxies), shortly after their birth. STAR-X's combination of excellent imaging and low particle background (due to orbit choice) makes this possible in a way that no other mission can.
Why STAR-X?
STAR-X is a timely response to Astro2020's recommendation for a space-based, sustaining time-domain and multi-messenger program.
The STAR-X science goals and objectives also address key Decadal priorities:
Providing Revolutionary Capabilities
- Unprecedented X-ray and UV volumetric survey speed, all packaged in a rapidly responding spacecraft.
- Provides a unique combination of large field of view (FOV), large effective area, low background, and excellent imaging.
- 10x more sensitive than eROSITA for characterizing diffuse emission.
- Faint point source discovery in wide-area surveys: 30x faster than Chandra, 100x faster than Swift XRT and 10x faster than Swift UVOT.
- X-ray point source sensitivity is 4x better than Chandra, >20x better than XMM , >50x better than Swift XRT, and 4x better than eROSITA (10 ks, Γ=1.7 power law).
Why Now?
X-ray and UV photons are among the earliest and most uniquely informative astrophysical signals that probe the inner regions around compact objects.
- There is currently no plan for the crucial simultaneous X-ray and UV survey coverage that complements, and multiplies the science return from, planned time-domain facilities like Roman & Rubin, while they are still operating (see below).
- STAR-X is technically ready, capitalizing on new lightweight, high resolution, low-cost X-ray optics made of single crystal silicon.
STAR-X fills the gap in X-ray and UV time domain coverage in the late 2020s, providing simultaneous X-ray and UV observations that complement optical, infrared, and gravitational wave facilities.
