2003/05/31 by V. Bozza, L. Mancini · 148 citations
Physics and Astronomy · #Astrophysical Phenomena and Observations #Binary black hole #Black hole (networking) #Gravitational lens #Intermediate-mass black hole #Pulsars and Gravitational Waves Research #Relativity and Gravitational Theory #Reverberation mapping #Spin-flip #Stellar black hole #Strong gravitational lensing #Supermassive black hole #astro-ph #gr-qc
paper · pdf · doi:10.1023/b:gerg.0000010486.58026.4f
published in General Relativity and Gravitation 36(2), 435-450 (Springer Science+Business Media) · 8 pages, 3 figures
arxiv created 2003/09/23 · openalex publication_date 2003/12/31 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
We calculate the time delay between different relativistic images formed by black hole gravitational lensing in the strong field limit. For spherically symmetric black holes, it turns out that the time delay between the first two images is proportional to the minimum impact angle. Their ratio gives a very interesting and precise measure of the distance of the black hole. Moreover, using also the separation between the images and their luminosity ratio, it is possible to extract the mass of the black hole. The time delay for the black hole at the center of our Galaxy is just few minutes, but for supermassive black holes with M=108 - 109 solar masses in the neighbourhood of the Local Group the time delay amounts to few days, thus being measurable with a good accuracy.