On the origin of clustering of frequency ratios in the atoll source 4U~1636-53

@article{42088,
   author = {Abramowicz, Marek and Bakala, Pavel and Stuchlík, Zdeněk and Török, Gabriel},
   article_location = {PL - Polská republika},
   article_number = {0},
   keywords = {X-rays:binaries, neutron stars, Accretion, accretion disks},
   language = {eng},
   issn = {0001-5237},
   journal = {Acta Astronomica},
   title = {On the origin of clustering of frequency ratios in the atoll source 4U~1636-53},
   volume = {58},
   year = {2008}
}

TY  - JOUR
ID  - 42088
AU  - Abramowicz, Marek - Bakala, Pavel - Stuchlík, Zdeněk - Török, Gabriel
PY  - 2008
TI  - On the origin of clustering of frequency ratios in the atoll source 4U~1636-53
JF  - Acta Astronomica
VL  - 58
SP  - 113-119
EP  - 113-119
SN  - 00015237
KW  - X-rays:binaries, neutron stars, Accretion, accretion disks
N2  - A long discussion has been devoted to the issue of clustering of the kHz QPO frequency ratios in the neutron star sources. While the distribution of ratios inferred from an occurrence of a single QPO seems to be consistent with a random walk, the distribution based on simultaneous detections of both peaks indicates a preference of ratios of small integers. Based on the public RXTE data we further investigate this issue for the source 4U1636. Quality factors and rms amplitudes of both the QPOs nearly equal to the points where the frequencies are commensurable, and where the twin QPO detections cluster. We discuss a connection of the clustering with the varying properties of the two QPO modes. We obtain results which are in qualitative agreement with theobserved distributions
ER  - 

ABRAMOWICZ, Marek, Pavel BAKALA, Zdeněk STUCHLÍK a Gabriel TÖRÖK. On the origin of clustering of frequency ratios in the atoll source 4U~1636-53. \textit{Acta Astronomica}. PL - Polská republika, roč.~58, s.~113-119. ISSN~0001-5237. 2008.