[Previous] | [Session 80] | [Next]
H.L. Marshall, C.R. Canizares, N.S. Schulz (MIT CSR)
Observations of SS 433 using the Chandra High Energy Transmission Grating Spectrometer (HETGS) are presented. The high resolution X-ray spectrum provides many diagnostics of the relativistic jet flow. Many emission lines of highly ionized elements are detected; all are detectably broadened by 2000-5000 km/s and the widths do not depend significantly on the characteristic emission temperature, suggesting that the emission occurs in a freely expanding region of constant collimation. Line ratios show that the base temperature of the jet is below 4 keV and may be closer to 2.5 keV. The X-ray luminosity during this observation was somewhat lower than average, which may be related to the lower jet temperature. The spectra are well fitted with a multi-temperature thermal model with temperatures of 1e6 to 1e7 K. The blue shifts of lines from low temperature gas are the same as those of high temperature gas, again indicating that jet acceleration occurs closer to the compact object. Using the H-like triplets, we show that the densities are very high and that the emission region has a size scale of order 2e11 cm. The continuum is well modelled by the thermal bremsstrahlung that matches the line emission so there is no evidence for a nonthermal continuum component. The HETGS zeroth order image shows extended emission on a much larger scale that is coincident with jets observed in the radio band.
This work was funded in part by contract SAO SV1-61010 and NASA contract NAS8-39073.
The author(s) of this abstract have provided an email address for comments about the abstract: mailto:hermanm@space.mit.edu