2016/01/31 by Y. Y. Kovalev, N. S. Kardashev, K. I. Kellermann +17
Physics and Astronomy · #Angular diameter #Astrophysical Phenomena and Observations #Astrophysics and Cosmic Phenomena #Brightness #Brightness temperature #Doppler effect #Galaxies: Formation, Evolution, Phenomena #Interferometry #Quasar #Supermassive black hole #Very-long-baseline interferometry #astro-ph.GA #astro-ph.HE
paper · pdf · doi:10.3847/2041-8205/820/1/l9
published as Astrophysical Journal Letters 820 (2016) L9 · 6 pages, 2 figures, 1 table; accepted by the Astrophysical Journal Letters
arxiv created 2016/03/02 · arxiv updated 2016/03/16 · openalex publication_date 2016/03/16 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
ABSTRACT Inverse Compton cooling limits the brightness temperature of the radiating plasma to a maximum of 10 11.5 K. Relativistic boosting can increase its observed value, but apparent brightness temperatures much in excess of 10 13 K are inaccessible using ground-based very long baseline interferometry (VLBI) at any wavelength. We present observations of the quasar 3C 273, made with the space VLBI mission RadioAstron on baselines up to 171,000 km, which directly reveal the presence of angular structure as small as 26 μ as (2.7 light months) and brightness temperature in excess of 10 13 K. These measurements challenge our understanding of the non-thermal continuum emission in the vicinity of supermassive black holes and require a much higher Doppler factor than what is determined from jet apparent kinematics.