2011/06/03 by D. M. Russell, J. C. A. Miller‐Jones, J. C. A. Miller-Jones +7 · 1 citation
Physics and Astronomy · #Accretion (finance) #Astronomy #Astrophysical Phenomena and Observations #Astrophysics #Astrophysics and Cosmic Phenomena #Binary number #Black hole (networking) #Galaxy #Jet (fluid) #Luminosity #Physics #Population #Pulsars and Gravitational Waves Research #astro-ph.HE
paper · pdf · doi:10.1088/2041-8205/739/1/l19
5 pages, 2 tables, 3 figures. Accepted to ApJ Letters, the EVLA first results edition
arxiv created 2011/06/03 · openalex publication_date 2011/08/30 · arxiv updated 2015/05/28 · openalex created_date 2020/11/23 · openalex updated_date 2026/08/05
We present ultradeep radio observations with the Expanded Very Large Array of 4U 1957+11, a Galactic black hole (BH) candidate X-ray binary known to exist in a persistent soft X-ray state. We derive a stringent upper limit of 11.4 μJy beam −1 (3σ) at 5–7 GHz, which provides the most rigorous upper limit to date on the presence of jets in a soft state BH X-ray binary (BHXB). X-ray, UV, and optical fluxes obtained within a few weeks of the radio data can be explained by thermal emission from the disk. At this X-ray luminosity, a hard state BHXB that follows the established empirical radio–X-ray correlation would be at least 330–810 times brighter at radio frequencies, depending on the distance to 4U 1957+11. This jet quenching of >2.5 orders of magnitude is greater than some models predict and implies that the jets are prevented from being launched altogether in the soft state. 4U 1957+11 is also more than one order of magnitude fainter than the faintest of the "radio-quiet" population of hard state BHs. In addition, we show that, on average, soft state stellar-mass BHs probably have fainter jets than most active galactic nuclei in a state equivalent to the soft state. These results have implications for the conditions required for powerful, relativistic jets to form and provide a new empirical constraint for time- and accretion mode-dependent jet models, furthering our understanding of jet production and accretion onto BHs.