Powerful Jet-driven Outflows from Two Bright Microquasars, Circinus X-1 and Cygnus X-1

Type Conference Paper
Names Paul Sell, S. Heinz
Proceedings Title Bulletin of the American Astronomical Society
Conference Name American Astronomical Society, AAS Meeting #219, #318.02
Volume 219
Date January 1, 2012
URL http://adsabs.harvard.edu/abs/2012AAS...21931802S
Library Catalog NASA ADS
Abstract We investigate the interaction of the jets from two bright microquasars, Circinus X-1 and Cygnus X-1, with the ISM. Our recent Chandra X-ray observations of Circinus X-1 reveal the first direct detection of an X-ray jet from a neutron star. We also see where the bipolar jet impacts the nearby ISM in terminating shock plumes that we refer to as "caps". We find that the caps are dominated by a cooled synchroton spectrum with a cooling time, tcool 1600 yr, suggesting that the jets are a fairly recent phenomenon. Our analysis of the caps also shows that the neutron star can produce jets as powerful and efficiently as black holes (3 x 1035 erg/s < Pjet < 2 x 1037 erg/s; ejet > 0.034%). In the case of Cygnus X-1, we use X-ray and optical spectroscopic observations to probe the limb-brightened radio and optical shell where the jet of the microquasar seems to be driving shocks into a nearby HII region. With our Chandra X-ray observations, we place upper limits on the mass flow rate across the shock and thus on the velocity of the shell. We also acquired multi-object spectroscopic observations along the shell to constrain the density and temperature of the outflow. Our analysis of jet driven outflows from these two microquasars highlights the different dominant physical mechanisms involved in jet-driven, parsec-scale shocks in the ISM.
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