How is cold gas transported from halo and galactic scales to SMBHs, and how does feedback close an observable self-regulation cycle?

Scope

In scope

Cooling, precipitation/CCA, disk and cloud transport, circumnuclear environments, and temporal links to jet or radiative feedback.

Out of scope

Black-hole mass or spin measurements without constraints on fueling or the feedback loop.

Why it matters

Connects SMBH growth and galaxy-scale feedback in a falsifiable causal loop.

Competing explanations

• Chaotic cold accretion or precipitation dominates
• Stable disks or bars dominate transport
• Hot Bondi accretion suffices in low-accretion systems
• Fueling and feedback are weakly correlated on observable timescales

Discriminating observables

• Angular momentum and inflow of molecular/ionized gas
• Circumnuclear X-ray absorption/emission and feedback ages
• Cooling-to-freefall ratios and multiphase condensation

Blockers

• Timescale mismatch
• Projection and inflow/outflow ambiguity
• Nuclear obscuration
• Inconsistent CCA morphology definitions