Q0957+561A , B is a double-imaged quasar that has been intensively observed during the last 10 years in different optical bands and with several telescopes , and we concentrated on recent public data obtained at the Apache Point Observatory ( APO ) and the Teide Observatory ( TO ) .
When an intrinsic event appears in the light curve of Q0957+561A , its twin event ( a similar feature ) is seen in the brightness record of Q0957+561B , and thus , one can measure the corresponding time delay .
The TO dataset includes two prominent twin events , which were detected with a time separation of 425 \pm 4 days .
On the other hand , from the APO dataset , we found a clear evidence for two different time delays associated with two pairs of twin events : 417.0 \pm 0.6 ( APO main twin events ) and 432.0 \pm 1.9 days ( APO secondary twin events ) , where the APO ( main ) –APO ( secondary ) difference delay is of - 15 \pm 2 days .
In agreement with the Yonehara ’ s idea , if the three pairs of twin events are originated inside a standard hybrid source ( accretion disk and circumnuclear stellar region ) , the three measured time delays indicate that they do not come from a common zone in the source .
Therefore , we can consider that the prominent features are caused by flares in a standard hybrid source and discuss on the size and nature of the region of flares .
In this paper it is showed that the more plausible interpretation is that two of the three flares are generated at distances ( from the central black hole ) larger than 90 pc .
Some stellar scenarios can explain the two flares far away from the black hole , while phenomena in the accretion disk can not cause them .