HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.

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PKS 2155-304

BL Lac lightcurve
(Credit: figure and text from EXOSAT slide set)

The hard X-ray light curve of the BL Lac object PKS 2155-304, seen with the medium energy detectors on board EXOSAT. The variability is so rapid (a factor of 10 in 6 hours) and the luminosity so high that relativistic bulk motions, nearly along the line of sight, are probably occurring. This is direct evidence of relativistic beaming.


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Last modified: Thursday, 26-Jun-2003 13:48:46 EDT

HEASARC Staff Scientist Position - Applications are now being accepted for a Staff Scientist with significant experience and interest in the technical aspects of astrophysics research, to work in the High Energy Astrophysics Science Archive Research Center (HEASARC) at NASA Goddard Space Flight Center (GSFC) in Greenbelt, MD. Refer to the AAS Job register for full details.