{"record":{"author":{"account_ref":null,"orcid":null},"builds_on":[],"content_schema":"pubphys.content.revision/1","content_sha256":"3485145a8a7d753237a0eaea19a5b63b57659b2d8dba5c3be0aa922f1bc0fd7e","created":"2026-10-03T07:17:55Z","files":[],"origin":{"assisted_by":[],"kind":"seed"},"parents":["5475cf5dc5b1a72283d26dc95dc6e00d7ea4e00096a7c6492e409a1816eeb011"],"salt":"44bc87aa9171b8314a4411fa7221e27b596ae5351a99955f4f8c8e61b48bbf34","schema":"pubphys.record/2","site":"pubphys.com","target":null,"type":"revision"},"content":{"answer_type":"mechanism","assisted_by":[],"external_id":"astro.first-smbh.little-red-dots","kind":"phenomenon","literature_status":"contested","n":"1","parents":[],"plain":"JWST found many tiny, very red objects in the young universe that show signs of a growing black hole but emit almost no X-rays and little hot dust. Whether they are black holes wrapped in dense gas, giant stars, or something else is unknown.","posed_since":"2023","precise":"Little red dots are compact (effective radius $<\\sim 100\\,\\mathrm{pc}$) sources, mostly at $z\\sim 4-9$, with V-shaped spectral energy distributions (blue rest-UV, red rest-optical), broad Balmer emission lines ($\\mathrm{FWHM}\\sim 1-4x10^{8}\\,\\mathrm{cm}/\\mathrm{s}$), strong Balmer breaks and Balmer absorption, weak X-ray and weak hot-dust emission, and number densities of order 100 times those extrapolated from UV-selected quasars. Identify the source of the continuum and of the line widths: an accreting black hole inside a dense, nearly dust-free gas envelope (black hole star), a supermassive star or quasi-star, a compact starburst, or a combination, with a model that reproduces the full spectrum.","problem_ref":null,"references":"","settled_by":"A single physical model that fits the rest-UV to mid-infrared spectra, the Balmer break and absorption, the X-ray weakness and the variability limits of a large spectroscopic sample.","status_note":"2025-2026 spectroscopic studies favor accreting black holes inside dense gas envelopes, while supermassive-star and super-Eddington outflow models are still being proposed in 2026.","title":"What are the compact red sources (little red dots) found by JWST?","topic_ref":"b31645054af13e29c5201707761f4cbb39ef8dced934561a5f80d1a755665bcf"},"attested":{"attestation":{"batch":null,"client_id":null,"id_token_sha256":null,"kind":"platform"},"record_hash":"caa7a750203c3d752d05b3a6ff5d92e4d0c768461296fbe5599fad0ba21d2cb2","schema":"pubphys.attested/1"},"envelope":{"attested_hash":"98dcfc8c3ca6a6a690e50380e730ce61d4ae47838b57c78cc6a1534320c3b6fa","platform_signature":{"key_id":"c6afc19b31429869751f06879c75cd64ea92654423d15b44be775bf1310a60da","sig":"2U3l6PO5jyKPh78Ev2SfXC1YlOlIcJjDW1K02imWSgKzef33mUXcfmaqQuCtdNczNMMEWqomHXpMlnm75nZ0DQ"},"schema":"pubphys.envelope/1"},"record_hash":"caa7a750203c3d752d05b3a6ff5d92e4d0c768461296fbe5599fad0ba21d2cb2","leaf_index":530}