ARRAKIHS Thermal and Structural Subsystem (TSS)

• Forschungsstelle: SBFI
• Projektnummer: P2023-UniZH ARRAKHIS
• Projekttitel Englisch: ARRAKIHS Thermal and Structural Subsystem (TSS)

Schlüsselwörter (Englisch)

ARRAKHIS UniZH SERI SBFI SEFRI SSO

Kurzbeschreibung (Englisch)

In Nov 2022, ARRAKIHS was chosen by the SPC as ESA's second F-class mission, with formal adoption set for Dec 2025. The mission will annually map 50 sq. degrees of sky in four bands to test the ΛCDM cosmological model. Using a mini satellite in LEO with a dual-binocular telescope, it aims to compile ultra-low brightness images of select galaxies. Performance specs include 31 mag./arcsec2 in visible and 30 mag./arcsec2 in near-infrared. The mission, using current tech, supports ESA's "Cosmic Vision" and will complement upcoming giant observatories. Switzerland will provide the thermal and structural subsystem for the payload, and this proposal seeks funding for its early-phase study.

Projektziele (Englisch)

The scientific objective of the ARRAKIHS mission is to image nearby galaxies similar to the Milky Way at low surface brightness in both visible and infrared wavelengths. The mission has specific goals:
1. To characterize the abundance and locations of satellite galaxies down to a magnitude of MV < -6 for a complete sample of Milky Way-like galaxies beyond
the Local Group.
2. To provide robust statistics concerning the numbers and shapes of wide and thin stellar streams.
3. To characterize the shape and extent of ultra-faint intra-halo light (IHL).

The data collected will be used to test various theories about the nature of dark matter that dominates the mass component of galaxies. The mission aims to resolve discrepancies and tensions between observations and the predictions of the Lambda Cold Dark Matter (ΛCDM) cosmological model. It also seeks to compare the ΛCDM model with alternative dark matter models, such as Warm Dark Matter (WDM) and Self-Interacting Dark Matter (SIDM).

The mission will produce a catalogue of ultra-low surface brightness satellite galaxies and stellar streams, enabling a comprehensive analysis that may confirm or challenge existing theories about dark matter and galaxy formation.