Jet spectral breaks in black hole X-ray binaries
Autor: | Sera Markoff, James Miller-Jones, Rob Fender, Elena Gallo, Jeroen Homan, Piergiorgio Casella, P. Gandhi, Dipankar Maitra, David M. Russell, T. Shahbaz, Ritaban Chatterjee, Kieran O'Brien, Andrew G. Cantrell |
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Přispěvatelé: | High Energy Astrophys. & Astropart. Phys (API, FNWI) |
Jazyk: | angličtina |
Rok vydání: | 2013 |
Předmět: |
High Energy Astrophysical Phenomena (astro-ph.HE)
Physics Jet (fluid) Accretion (meteorology) 010308 nuclear & particles physics Infrared Astrophysics::High Energy Astrophysical Phenomena FOS: Physical sciences Astronomy Spectral density Astronomy and Astrophysics Astrophysics Astrophysics::Cosmology and Extragalactic Astrophysics 01 natural sciences Luminosity Magnetic field Black hole Space and Planetary Science 0103 physical sciences High Energy Physics::Experiment Astrophysics - High Energy Astrophysical Phenomena 010303 astronomy & astrophysics Order of magnitude |
Zdroj: | ResearcherID Monthly Notices of the Royal Astronomical Society, 429(1), 815-832. Oxford University Press |
ISSN: | 1365-2966 0035-8711 |
Popis: | In X-ray binaries, compact jets are known to commonly radiate at radio to infrared frequencies, whereas at optical to gamma-ray energies, the contribution of the jet is debated. The total luminosity, and hence power of the jet is critically dependent on the position of the break in its spectrum, between optically thick (self-absorbed) and optically thin synchrotron emission. This break, or turnover, has been reported in just one black hole X-ray binary (BHXB) thus far, GX 339-4, and inferred via spectral fitting in two others, A0620-00 and Cyg X-1. Here, we collect a wealth of multiwavelength data from the outbursts of BHXBs during hard X-ray states, in order to search for jet breaks as yet unidentified in their spectral energy distributions. In particular, we report the direct detection of the jet break in the spectrum of V404 Cyg during its 1989 outburst, at nu_b = (1.8 +- 0.3) x 10^14 Hz (1.7 +- 0.2 microns). We increase the number of BHXBs with measured jet breaks from three to eight. Jet breaks are found at frequencies spanning more than two orders of magnitude, from nu_b = (4.5 +- 0.8) x 10^12 Hz for XTE J1118+480 during its 2005 outburst, to nu_b > 4.7 x 10^14 Hz for V4641 Sgr in outburst. A positive correlation between jet break frequency and luminosity is expected theoretically; nu_b \propto L_nu,jet^~0.5 if other parameters are constant. With constraints on the jet break in a total of 12 BHXBs including two quiescent systems, we find a large range of jet break frequencies at similar luminosities and no obvious global relation (but such a relation cannot be ruled out for individual sources). We speculate that different magnetic field strengths and/or different radii of the acceleration zone in the inner regions of the jet are likely to be responsible for the observed scatter between sources. (abridged) MNRAS accepted |
Databáze: | OpenAIRE |
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