Parsec-scale Bipolar X-ray Shocks Produced by Powerful Jets from the Neutron Star Circinus X-1
Brandt, W. N.; Wijnands, R.; Nowak, M. A.; van der Klis, M.; Casella, P.; Fender, R. P.; Heinz, S.; Sell, P. H.; Jonker, P. G.; Tudose, V.; Schulz, N. S.; Calvelo, D. E.; Soleri, P.
United States, United Kingdom, Netherlands, Romania
Abstract
We report the discovery of multi-scale X-ray jets from the accreting neutron star X-ray binary, Circinus X-1. The bipolar outflows show wide opening angles and are spatially coincident with the radio jets seen in new high-resolution radio images of the region. The morphology of the emission regions suggests that the jets from Circinus X-1 are running into a terminal shock with the interstellar medium, as is seen in powerful radio galaxies. This and other observations indicate that the jets have a wide opening angle, suggesting that the jets are either not very well collimated or precessing. We interpret the spectra from the shocks as cooled synchrotron emission and derive a cooling age of ~1600 yr. This allows us to constrain the jet power to be 3 × 1035 erg s-1 <~ P jet <~ 2 × 1037 erg s-1, making this one of a few microquasars with a direct measurement of its jet power and the only known microquasar that exhibits stationary large-scale X-ray emission.