Logo image
Back
Ardua: Unveiling the Baryon Cycle from Stars to the Cosmic Web
Preprint   Open access

Ardua: Unveiling the Baryon Cycle from Stars to the Cosmic Web

Carlos J Vargas, Caroline Kilbourne, Haeun Chung, Erika Hamden, Ralph Kraft, Joseph N Burchett, Lauren Corlies, Claude-André Faucher-Giguère, Kevin France, Keri Hoadley, …
ArXiv.org
arXiv
07/13/2026
DOI: 10.48550/arxiv.2607.11865
url
https://doi.org/10.48550/arxiv.2607.11865View
Preprint (Author's original) This preprint has not been evaluated by subject experts through peer review. Preprints may undergo extensive changes and/or become peer-reviewed journal articles. Open Access

Abstract

The circumgalactic medium (CGM) – the multiphase gas reservoirs surrounding galaxies – remains the least understood component of the baryon cycle governing galaxy growth, despite its central role in the Astro2020 Decadal Survey's priorities. Existing constraints come almost exclusively from pencil-beam absorption spectroscopy, leaving the spatial structure, kinematics, and phase interactions of CGM gas fundamentally unmapped. We present Ardua, a mission concept for NASA's ASTRA Initiative that combines wide-field far-ultraviolet spectroscopy with a Line Emission Mapper (LEM)-derived X-ray microcalorimeter instrument to obtain the first comprehensive emission maps spanning the full CGM temperature range, including cool neutral gas, ionized warm-hot phase gas, and the volume-filling hot corona. By observing more than 50 nearby galaxies comprehensively in the UV and X-ray, Ardua will test competing galaxy formation models, resolve multiphase gas flows and feedback-driven outflows, and extend baryon-cycle science to the intergalactic medium and the environments of exoplanet-hosting stars. Beyond its core CGM/IGM program, Ardua's wide-field, high-sensitivity instruments are designed to serve as a flexible community resource, supporting guest-investigator science across astrophysics. No planned or approved mission is designed to deliver this combined UV/X-ray survey capability.
 Physics - Astrophysics of Galaxies Physics - High Energy Astrophysical Phenomena Physics - Instrumentation and Methods for Astrophysics

Details

Metrics

1 Record Views
Logo image