KnowraBroad-line regionLinked fromLinked fromThe 5 pages that link to Broad-line region, each with the reason it gives.All 5Broader topic 4Related 1Active galactic nucleusBroader topic: Its line widths reveal gas moving rapidly in the nucleus’s gravitational field.Seyfert galaxyBroader topic: Its high-velocity gas produces the broad permitted lines in Seyfert 1 spectra.BlazarRelated: Its photons can serve as seed light for high-energy emission in some blazars.NGC 4151Broader topic: Its rapidly responding gas allows the nucleus’s central mass to be estimated.NGC 5548Broader topic: Its changing emission lines let astronomers measure the nucleus’s structure and response time.