{"work":{"id":"db8a27ac-78e8-4a56-92a0-4b15ef45ff60","openalex_id":null,"doi":null,"arxiv_id":"1712.01860","raw_key":null,"title":"An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5","authors":null,"authors_text":"Banados, E","year":2017,"venue":"astro-ph.GA","abstract":"Quasars are the most luminous non-transient objects known and as a result they enable studies of the Universe at the earliest cosmic epochs. Despite extensive efforts, however, the quasar ULAS J1120+0641 at z=7.09 has remained the only one known at z>7 for more than half a decade. Here we report observations of the quasar ULAS J134208.10+092838.61 (hereafter J1342+0928) at redshift z=7.54. This quasar has a bolometric luminosity of 4e13 times the luminosity of the Sun and a black hole mass of 8e8 solar masses. The existence of this supermassive black hole when the Universe was only 690 million years old---just five percent of its current age---reinforces models of early black-hole growth that allow black holes with initial masses of more than about 1e4 solar masses or episodic hyper-Eddington accretion. We see strong evidence of absorption of the spectrum of the quasar redwards of the Lyman alpha emission line (the Gunn-Peterson damping wing), as would be expected if a significant amount (more than 10 per cent) of the hydrogen in the intergalactic medium surrounding J1342+0928 is neutral. We derive a significant fraction of neutral hydrogen, although the exact fraction depends on the modelling. However, even in our most conservative analysis we find a fraction of more than 0.33 (0.11) at 68 per cent (95 per cent) probability, indicating that we are probing well within the reionization epoch of the Universe.","external_url":"https://arxiv.org/abs/1712.01860","cited_by_count":null,"metadata_source":"pith","metadata_fetched_at":"2026-07-10T10:27:02.239147+00:00","pith_arxiv_id":"1712.01860","created_at":"2026-05-10T14:40:48.203289+00:00","updated_at":"2026-07-10T10:27:02.239147+00:00","title_quality_ok":true,"display_title":"An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5","render_title":"An 800-million-solar-mass black hole in a significantly neutral Universe at redshift 7.5"},"hub":{"state":{"work_id":"db8a27ac-78e8-4a56-92a0-4b15ef45ff60","tier":"hub","tier_reason":"10+ Pith inbound or 1,000+ external citations","pith_inbound_count":16,"external_cited_by_count":null,"distinct_field_count":4,"first_pith_cited_at":"2018-07-17T04:05:07+00:00","last_pith_cited_at":"2026-07-09T09:07:39+00:00","author_build_status":"not_needed","summary_status":"needed","contexts_status":"needed","graph_status":"needed","ask_index_status":"not_needed","reader_status":"not_needed","recognition_status":"not_needed","updated_at":"2026-08-19T00:30:06.194421+00:00","tier_text":"hub"},"tier":"hub","role_counts":[{"context_role":"background","n":3}],"polarity_counts":[{"context_polarity":"background","n":3}],"runs":{},"summary":{},"graph":{},"authors":[]}}