Radio VLBI and X-ray Spectroscopy of the SS 433 Jets
Abstract
In the binary system SS 433, oppositely directed, precessing jets emit line emission from highly ionized plasma moving at 0.26c from the compact object. In a 2005 Chandra High Energy Transmission Grating Spectrometer (HETGS) observations of SS 433, we found a large Doppler shift change on a time scale of 20 ks, a time much shorter than the known dynamical times. The rapid change could be related to the formation and ejection of a jet knot, as observed in VLBI observations, perhaps as a leptonic jet impinges on a disk wind and shock heats it. More recent data were obtained to test this model in a long continuous HETGS observation. The VLBA and Chandra HETGS data were obtained but while no radio ejections were observed during the Chandra observation, there were interesting aspects to the observations. First, although the jet emission lines were expected to vary with the usual precession period (162 days) or with the period of the nodding motion (6.6 days), we did not detect the expected Doppler shifts in over 120 ks of exposure. Furthermore, there is new evidence for jet curvature that has not been previously reported. We will show how XARM can provide new constraints on the physical parameters at the jet origin.Support for this work was provided in part by the National Aeronautics and Space Administration (NASA) through the Smithsonian Astrophysical Observatory (SAO) contract SV3-73016 to MIT for support of the Chandra X-Ray Center (CXC), which is operated by SAO for and on behalf of NASA under contract NAS8-03060. Support was also provided by NASA under grant GO4-15040A to MIT.
- Publication:
-
42nd COSPAR Scientific Assembly
- Pub Date:
- July 2018
- Bibcode:
- 2018cosp...42E2184M