How do feedback and environment set the radial thermodynamic structure and retained hot-baryon fraction of galaxy halos over time?

Scope

In scope

Galaxy/group-scale CGM, early-type hot halos, radial density-temperature-entropy structure, retained hot-gas fraction, satellite stripping, and time evolution.

Out of scope

Excludes results centered on bulk ICM pressure or cluster-merger thermodynamics, and stellar or dark-matter structure without a direct hot-gas constraint.

Why it matters

Connects missing baryons to environmental quenching, feedback recycling, and observable galaxy hot-halo inventories in a bounded, discriminating question.

Competing explanations

• Feedback sets a near-universal entropy floor that dominates the retained hot-gas fraction
• Environmental stripping dominates hot-CGM loss in satellites
• The balance between feedback and environment varies with halo mass and central/satellite state

Discriminating observables

• Radial density, temperature, entropy, and f_hot profiles
• f_hot versus halo mass, environment, and infall time
• Slope, normalization, and mass dependence of the L_X--T relation
• Joint X-ray, tSZ, and absorption-line inventory

Blockers

• Low-surface-brightness background and stray light
• Inconsistent hot/cool phase definitions and observational selection
• Projection, radial coverage, and environmental-history degeneracies