Detection of the Second Qpo
نویسندگان
چکیده
Using a new technique to improve the sensitivity to weak Quasi-Periodic Oscillations (QPO) we discovered a new QPO peak at about 1100 Hz in the March 1996 outburst observations of 4U 1608–52, simultaneous with the ∼ 600 − 900 Hz peak previously reported from these data. The frequency separation between the upper and the lower QPO peak varied significantly from 232.7± 11.5 Hz on March 3, to 293.1± 6.6 Hz on March 6. This is the first case of a variable kHz peak separation in an atoll source.
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