Steady jets from radiatively efficient hard states in GRS 1915+105
Artikel i vetenskaplig tidskrift, 2010

Recent studies of different X-ray binaries (XRBs) have shown a clear correlation between the radio and X-ray emission. We present evidence of a close relationship found between the radio and X-ray emission at different epochs for GRS 1915+105, using observations from the Ryle Telescope and Rossi X-ray Timing Explorer satellite. The strongest correlation was found during the hard state (also known as the "plateau" state), where a steady AU-scale jet is known to exist. Both the radio and X-ray emission were found to decay from the start of most plateau states, with the radio emission decaying faster. An empirical relationship of S radio. S. X-ray was then fitted to data taken only during the plateau state, resulting in a power-law index of xi similar to 1.7 +/- 0.3, which is significantly higher than in other black hole XRBs in a similar state. An advection-flow model was then fitted to this relationship and compared to the universal XRB relationship as described by Gallo et al. (2003, MNRAS, 344, 60). We conclude that either (I) the accretion disk in this source is radiatively efficient, even during the continuous outflow of a compact jet, which could also suggest a universal turn-over from radiatively inefficient to efficient for all stellar-mass black holes at a critical mass accretion rate (m(c) approximate to 10(18.5) g/s); or (II) the X-rays in the plateau state are dominated by emission from the base of the jet and not the accretion disk (e. g. via inverse Compton scattering from the outflow).


low/hard state

gx 339-4



stars: winds

accretion disks

black-hole binaries


black hole physics

radio/x-ray correlation

accretion rate



X-rays: binaries


radiation mechanisms:

ISM: jets and




Anthony Rushton

Chalmers, Rymd- och geovetenskap, Onsala rymdobservatorium

R. Spencer

R. Fender

G. Pooley

Astronomy and Astrophysics

0004-6361 (ISSN) 1432-0746 (eISSN)

Vol. 524


Astronomi, astrofysik och kosmologi