SIMBAD references

We present new time-resolved photometric observations and images at 2.2µm of a small sample of X-ray variable Seyfert 1 nuclei. After correcting for dilution by the host galaxy in the observing aperture, we compare the fractional variation, over the timescales of the observations, in the near-infrared (NIR) to that expected in the X rays. We have not detected with confidence any NIR variability on timescales short enough to be incompatible with the dust reradiation scenario. The galaxy-corrected upper limits which we have obtained for variations on short timescales, typical of non-thermal processes, imply that the NIR emission is dominated by a slowly varying, presumably reprocessed, component which accounts for no less than 80%-90% of the total.