Distribution of Kilohertz QPO Frequencies and Their Ratios in the Atoll Source 4U 1636-53

• Autorzy: Török G. , Abramowicz M. A. , Bakala P. , Bursa M. , Horák J. , Kluźniak W. , Rebusco P. , Stuchlík Z.
• Języki publikacji: EN

Abstrakty

EN

A recently published study on long term evolution of the frequencies of the kilohertz quasi-periodic oscillations (QPOs) in the atoll source 4U 1636-53 concluded that there is no preferred frequency ratio in a distribution of twin QPOs that was inferred from the distribution of a single frequency alone. However, we find that the distribution of the ratio of actually observed pairs of kHz QPO frequencies is peaked close to the 3/2 value, and possibly also close to the 5/4 ratio. To resolve the apparent contradiction between the two studies, we examine in detail the frequency distributions of the lower kHz QPO and the upper kHz QPO detected in our data set. We demonstrate that for each of the two kHz QPOs (the lower or the upper), the frequency distribution in all detections of a QPO differs from the distribution of frequency of the same QPO in the subset of observations where both the kHz QPOs are detected. We conclude that detections of individual QPOs alone should not be used for calculation of the distribution of the frequency ratios.

Słowa kluczowe

EN

X-rays: binaries; Stars: neutron; Accretion; accretion disks

• Wydawca: Copernicus Foundation for Polish Astronomy
• Czasopismo: Acta Astronomica
• Rocznik: 2008
• Tom: Vol. 58, No. 1
• Strony: 15--21
• Opis fizyczny: Bibliogr. 12 poz., wykr.

Twórcy

autor

Török G.

• Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo nám.13, 746-01 Opava, Czech Republic

autor

Abramowicz M. A.

• Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo nám.13, 746-01 Opava, Czech Republic
• Department of Physics, Göteborg University, S-412 96 Göteborg, Sweden
• Copernicus Astronomical Centre PAN, Bartycka 18, 00-716 Warsaw, Poland

autor

Bakala P.

• Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo nám.13, 746-01 Opava, Czech Republic

autor

Bursa M.

• Astronomical Institute of the Academy of Sciences, Boční II 1401/1a, 141-31 Praha 4, Czech Republic

autor

Horák J.

• Astronomical Institute of the Academy of Sciences, Boční II 1401/1a, 141-31 Praha 4, Czech Republic

autor

Kluźniak W.

• Copernicus Astronomical Centre PAN, Bartycka 18, 00-716 Warsaw, Poland
• Johannes Kepler Institute of Astronomy, Zielona Gora University, ul. Lubuska 2, 65-265 Zielona Góra, Poland

autor

Rebusco P.

• MIT Kavli Institute for Astrophysics and Space Research, 77 Massachusetts Avenue, 37, Cambridge, MA 02139, USA
• Max-Planck-Institute for Astrophysics, Karl-Schwarzschild-Str. 1, D-85741 Garching, Germany

autor

Stuchlík Z.

• Institute of Physics, Faculty of Philosophy and Science, Silesian University in Opava, Bezručovo nám.13, 746-01 Opava, Czech Republic

Bibliografia

• Abramowicz, M.A., Bulik, T., Bursa, M., and Klu´zniak, W. 2003, A&A, 404, L21.
• Abramowicz, M.A., Barret, D., Bursa, M., Horák, J., Klu´zniak,W., Rebusco, P., and Török, G. 2005, in: Proceedings of RAGtime 6/7, Eds. S. Hledík, Z. Stuchlík, Opava.
• Barret, D., Kluzniak, W., Olive, J.F., Paltani, S., and Skinner, G.K. 2005a, MNRAS, 357, 1288.
• Barret, D., Olive, J.F., and Miller, M.C. 2005b, MNRAS, 361, 855.
• Barret, D., Olive, J.F., and Miller, M.C. 2005c, Astron. Nachr., 326, 808.
• Barret, D., Olive, J.F., and Miller, M.C. 2006, MNRAS, 370, 1140.
• Belloni, T., Méndez, M., and Homan, J. 2005, A&A, 437, 209.
• Belloni, T., Méndez, M., and Homan, J. 2007, MNRAS, 379, 247.
• Klu´zniak, W., and Abramowicz, M.A. 2000, preprint; astro-ph/0105057.
• Klu´zniak, W., and Abramowicz, M.A. 2001, Acta Physica Polonica B, 32, 3605.
• Méndez, M., van der Klis, M., Wijnands, R., Ford, E.C., van Paradijs, J., and Vaughan, B.A. 1998, ApJ, 505, L23.
• Zhang, C.M., Yin H.X., Zhao, Y.H., Song, L.M., and Zhang, F. 2006, MNRAS, 366, 1373.