Astronomy and Astrophysics – Astrophysics
Scientific paper
2000-10-03
Astronomy and Astrophysics
Astrophysics
8 pages, 2 figures, 2 tables; accepted for ApJ Letters
Scientific paper
10.1086/319134
We report the discovery of a highly coherent oscillation in a type-I X-ray burst observed from 4U 1916-053 by the Rossi X-ray Timing Explorer (RXTE). The oscillation was most strongly detected approx. 1 s after the burst onset at a frequency of 269.3 Hz, and it increased in frequency over the following 4 seconds of the burst decay to a maximum of around 272 Hz. The total measured drift of 3.58 +/- 0.41 Hz (1 sigma) represents the largest fractional change in frequency (1.32 +/- 0.15 %) yet observed in any burst oscillation. If the asymptotic frequency of the oscillation is interpreted in terms of a decoupled surface burning layer, the implied neutron star spin period is around 3.7 ms. However, the expansion of the burning layer required to explain frequency drift during the burst is around 80 m, substantially larger than expected theoretically (assuming rigid rotation). The oscillation was not present in the persistent emission before the burst, nor in the initial rise. When detected its amplitude was 6-12% (RMS) with a roughly sinusoidal profile. The burst containing the oscillation showed no evidence for photospheric radius expansion, while at least 5 of the other 9 bursts observed from the source by RXTE during 1996 and 1998 did. No comparable oscillations were detected in the other bursts. A pair of kilohertz quasi-periodic oscillations (QPOs) has been previously reported from this source with a mean separation of 348 +/- 12 Hz. 4U 1916-053 is the first example of a source where the burst oscillation frequency is significantly smaller than the frequency separation of the kHz QPOs.
Chakrabarty Deepto
Galloway Duncan K.
Muno Michael P.
Savov Pavlin
No associations
LandOfFree
Discovery of a 270 Hz X-Ray Burst Oscillation in the X-Ray Dipper 4U 1916-053 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 270 Hz X-Ray Burst Oscillation in the X-Ray Dipper 4U 1916-053, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Discovery of a 270 Hz X-Ray Burst Oscillation in the X-Ray Dipper 4U 1916-053 will most certainly appreciate the feedback.
Profile ID: LFWR-SCP-O-327554