Discovery of a second kHz QPO peak in 4U 1608-52

Details Discovery of a second kHz QPO peak in 4U 1608-52 Discovery of a second kHz QPO peak in 4U 1608-52

1997-12-05

arxiv.org/abs/astro-ph/9712085v1

Astronomy and Astrophysics

Astrophysics

To appear in ApJL. AAS LaTex v4.0 (9 pages, 2 ps-figures)

Scientific paper

10.1086/311162

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 $232.7 \pm 11.5$ Hz on March 3, to $293.1 \pm 6.6$ Hz on March 6. This is the first case of a variable kHz peak separation in an atoll source. We discuss to what extent this result could be accommodated in beat-frequency models such as proposed for the kHz QPOs. We measured the rms fractional amplitude of both QPOs as a function of energy, and we found that the relation is steeper for the lower than for the upper frequency peak. This is the first source where such difference between the energy spectrum of the two kHz QPOs could be measured.

Affiliated with

Also associated with

No associations

Rating

Discovery of a second kHz QPO peak in 4U 1608-52 does not yet have a rating. At this time, there are no reviews or comments for this scientific paper.

If you have personal experience with Discovery of a second kHz QPO peak in 4U 1608-52, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Discovery of a second kHz QPO peak in 4U 1608-52 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-514957