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E.K. Strobel (Washington State University), J.R. Webb, E.S. Howard (Florida International University)
As part of the 1998 International Mrk 421 campaign, we observed Mrk 421 in the optical while it was also being intensively monitored in the X-ray band. A flare was detected in X-ray by the ASCA satellite, but no significant flux variations were detected in the optical. This may indicate that X-rays are emitted from a different part of the blazar than the optical emission, or that there is a significant time delay between the X-ray and optical emissions. Should this be true, current blazar models may need to be changed. In reducing the optical data, the differences between the results given by IRAF packages Phot and Allstar were examined. Since Mrk 421 is surrounded by a bright galaxy, we were concerned about Phot's accuracy in calculating the magnitude of the blazar. The results indicate that Allstar and Phot produce similar results for this object.
The author(s) of this abstract have provided an email address for comments about the abstract: estrobel@wsunix.wsu.edu