2004/12/31 by D. Rusin, Charles R. Keeton, C. R. Keeton +2
Physics and Astronomy · #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Binary black hole #Black hole (networking) #Galaxies: Formation, Evolution, Phenomena #Galaxy #Gravitational wave #Intermediate-mass black hole #Mass distribution #Physics #Radio Astronomy Observations and Technology #Redshift #Spin-flip #Stellar black hole #Supermassive black hole #astro-ph
paper · pdf · doi:10.1086/432439
published as Astrophys.J. 627 (2005) L93-L96 · 12 pages including 4 figures, ApJL in press (edited to match published version, one typo corrected)
openalex publication_date 2005/06/20 · arxiv created 2005/06/22 · arxiv updated 2009/12/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
The supermassive black hole at the center of a distant galaxy can be weighed, in rare but realistic cases, when the galaxy acts as a strong gravitational lens. The central image that should be produced by the lens is either destroyed or accompanied by a second central image, depending on the mass of the black hole. We demonstrate that when a central image pair is detected, the mass of the black hole can be determined with an accuracy of ≲0.1 dex, if the form of the smooth mass distribution near the galaxy core is known. Uncertainty in the central mass distribution introduces a systematic error in the black hole mass measurement. However, even with nearly complete ignorance of the inner mass distribution, the black hole mass can still be determined to within a factor of 10. Central image pairs should be readily observable with future radio interferometers, allowing this technique to be used for a census of supermassive black holes in inactive galaxies at significant redshift (0.2 ≲ z ≲ 1.0).