{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"13d4e5b64d20383301e78383a109a30d0d71ff57372b19059de311438f4a8385","created":"2026-10-03T07:17:55Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"b32e51cecdd8d5dc2fa300f4ffe91429f8d873ef4b90f5f639ad38e7795595d8","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"astro.galaxy-quenching.mechanism","kind":"phenomenon","literature_status":"open","n":"1","parents":[],"plain":"Above a certain mass most galaxies stop forming stars and stay that way. Black hole outbursts, heating of infalling gas by shocks, and other effects are all candidates, and the relative roles are unknown.","posed_since":"","precise":"Identify the dominant process that shuts off and keeps off star formation in central galaxies above $M_* \\sim 3x10^{10}\\ M_{\\mathrm{sun}}$ (halo mass ~ $10^{12}\\ M_{\\mathrm{sun}}$): radiative AGN winds, radio-jet heating, virial shock heating of accreted gas, morphological stabilization of the gas disk, or cosmic-ray heating. The answer is an energy and momentum budget showing which process reproduces the quenched fraction as a function of $M_*$, halo mass and redshift.","problem_ref":null,"references":"","settled_by":"Cosmological simulations whose feedback is constrained by measured outflow energetics, reproducing the quenched fraction versus $M_{*}$ and $z$ without retuning, plus direct observation of halo gas thermodynamics around quenched galaxies.","status_note":"","title":"What stops star formation in massive galaxies?","topic_ref":"a746179504180cf8b606d4dc0f5a5cf5a2da027fbd03f697a20b609958ec0579"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"09accbaed3934624b5734eea03da8c930ea8ff01c1dddff48a801f9cf6768401","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"3cfad31055c3a33d402d82f501b5b821e1e1b0590863ed06e85d82120ed5910e","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"ygXrMeNqRyQSTQ9pVA8EE3GWyURnp76lmucf_Cbv9_4FoegvqhhFo-FJmW8fPlURsRClWemLHfc02NWiuB5pDQ"},"schema":"pubphys.envelope/1"},"record_hash":"09accbaed3934624b5734eea03da8c930ea8ff01c1dddff48a801f9cf6768401","leaf_index":540}