Figure 1 (upper panel) displays the 0.4-8 keV light curves of PG1211+143 measured by the HETGS , which were obtained from a combination of the MEG and HEG data. The observation numbers are labeled (with “1-6”) according to the time sequence of the exposures listed in the first column of Table 1. The source appeared to be at its lowest brightness at the beginning, while it reached the highest brightness on April 13 (4th observation). It then returned to a lower brightness on April 15. As can be seen, there were only moderate changes in brightness over the 9-day observation.
Figure 1 (lower panel) displays the FUV continua of PG1211+143 measured by the HST-COS . The G140L continuum light curve has an average flux of (1430Å ergcmsÅ, and shows very small variations in two days, which is consistent with the G130M continuum (1430Å ergcmsÅ. The G140L data combined with X-ray, infrared, and radio were used for constructing the ionizing SED for the photoionization modeling discussed in §5.1.