Discovery of a kHz QPO in 2S 0918-549

Details Discovery of a kHz QPO in 2S 0918-549 Discovery of a kHz QPO in 2S 0918-549

2001-01-10

arxiv.org/abs/astro-ph/0101150v1

Astronomy and Astrophysics

Astrophysics

Accepted for publication in ApJ, uses emulateapj, 7 pages, 4 figures (figure 4 is in color)

Scientific paper

We report the discovery of a kilohertz quasi-periodic oscillation (kHz QPO) in the low-mass X-ray binary (LMXB) 2S 0918-549. The kHz QPO has a frequency of 1156+-9 Hz, a FWHM of 70+-20 Hz, and a fractional rms amplitude of 18%+-2%. We also detected for the first time a type I X-ray burst in this source. The compact object must therefore be a neutron star. Finally, we were able to classify the source as an atoll source exhibiting the full complement of spectral/timing states of this class (island and banana). From the peak burst flux an upper limit on the persistent luminosity can be derived of 0.5% of the Eddington luminosity, making 2S 0918-549 one of the least luminous LMXBs showing a kHz QPO. We compare the fractional rms amplitudes of the upper kHz QPO across the ensemble of LMXBs. We find a strong anticorrelation with luminosity. In LMXBs with luminosities ~100 times lower than those of Z-sources, the fractional rms amplitude is a factor ~10 larger.

Affiliated with

Also associated with

No associations

Rating

Discovery of a kHz QPO in 2S 0918-549 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 kHz QPO in 2S 0918-549, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Discovery of a kHz QPO in 2S 0918-549 will most certainly appreciate the feedback.

Rate now

Comments { 0 }

Profile ID: LFWR-SCP-O-65603