The Seyfert 2 galaxy Mrk 1210 was found to exhibit a flat hard X-ray component by ASCA , although ASCA could not distinguish whether it is an absorbed direct component or a reflected one .
We then observed Mrk 1210 with BeppoSAX , and found that the X-ray spectral properties are quite different from those of ASCA , as have been confirmed with XMM-Newton ; the flux is significantly higher than that in the ASCA observation , and a clear absorption cut-off appears below 5 keV .
A bright hard X-ray emission is detected up to 100 keV .
The reflection component is necessary to describe the BeppoSAX PDS spectrum , and represents the ASCA hard component very well .
Therefore , the hard component in the ASCA spectrum is a reflected one , whose intensity is almost constant over 6 years .
This indicates that a dramatic spectral variability is attributed to a large change of the absorption column density by a factor of > 5 , rather than the variability of the nuclear emission .
The change in the absorption-column density means that the torus is not homogeneous , but has a blobby structure with a typical blob size of < 0.001 pc .