The X-ray band encodes key spectral features that reveal the physics underlying transient and multi-messenger events, identified as a Priority Area by Astro2020.

Goal 3

What Powers the Diversity of Explosive Phenomena Across Time and Multi-Messenger Domains?

Our Universe is adorned with a rich tapestry of explosive and energetic events, producing X-rays as jets form, matter collides, and accreting systems are created or destroyed. Our Galaxy contains sites where magnetic fields accelerate ions to extreme energies, producing high-energy photons as they gyrate in the strong fields and collide with the surrounding material. The high-energy spectra of these time-domain and multi-messenger events reveal the nature and physics of the source (Fig.2-4).

Goal 3 investigates what powers the diversity of extreme time domain and multi-messenger events, identified as a Priority Area by Astro2020. This goal motivates two science objectives.

  • Objective 5: reveals the nature of the most extreme accelerators in our Galaxy by measuring high-energy (>40 keV) X-ray emission from a sample of Galactic gamma-ray sources.
  • Objective 6: will provide a community resource for exploring the dynamic universe across the X-ray band with an unanticipated target of opportunity observations:

For more information about Goal 3, see Mori et al. (FrASS, submitted; arXiv:2311.04851) and Brightman et al. (FrASS, submitted; arXiv:2311.04856).

HEX-P's high throughput and spacial resolution will allow for detailed studies of crowded source regions, allowing us to classify stellar remnant populations.

Goal 3 Science Team

Sub-groups and their Leads:

Galactic Gamma-Ray Sources — Kaya Mori (Columbia University)

Time Domain / Multi-Messenger Astrophysics (TDAMM) — Murray Brightman (Caltech)

TDAMM: Gravitational Waves — Raffaella Margutti (UC-Berkeley)

TDAMM: AGN — Arne Rau (MPE)

TDAMM: Tidal Disruption Events — Suvi Gezari (STScI)