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Title: Low Frequency Quasi-periodic Oscillations in the High-eccentric LMXB Cir X-1: Extending the WK Correlation for Z Sources

Abstract

Using archival Rossi X-ray Timing Explorer ( RXTE ) data, we studied the low-frequency quasi-periodic oscillations (LFQPOs) in the neutron star low-mass X-ray binary (LMXB) Cir X-1 and examined their contribution to frequency–frequency correlations for Z sources. We also studied the orbital phase effects on the LFQPO properties and found them to be phase independent. Comparing LFQPO frequencies in different classes of LMXBs, we found that systems that show both Z and atoll states form a common track with atoll/BH sources in the so-called WK correlation, while persistent Z systems are offset by a factor of about two. We found that neither source luminosity nor mass accretion rate is related to the shift of persistent Z systems. We discuss the possibility of a misidentification of fundamental frequency for horizontal branch oscillations from persistent Z systems and interpreted the oscillations in terms of models based on relativistic precession.

Authors:
;  [1];  [2];  [3]
  1. Department of Astronomy, Beijing Normal University, Beijing 100875 (China)
  2. INAF-Osservatorio Astronomico di Brera, Via E, Bianchi 46, I-23807 Merate (Italy)
  3. Laboratory for Particle Astrophysics, CAS, Beijing 100049 (China)
Publication Date:
OSTI Identifier:
22663543
Resource Type:
Journal Article
Resource Relation:
Journal Name: Astrophysical Journal; Journal Volume: 841; Journal Issue: 2; Other Information: Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
79 ASTROPHYSICS, COSMOLOGY AND ASTRONOMY; ACCRETION DISKS; BINARY STARS; BLACK HOLES; COMPARATIVE EVALUATIONS; CORRELATIONS; COSMIC X-RAY SOURCES; LUMINOSITY; MASS; NEUTRON STARS; OSCILLATIONS; PERIODICITY; PRECESSION; RELATIVISTIC RANGE; X RADIATION

Citation Formats

Bu, Qingcui, Chen, Li, Belloni, T. M., and Qu, Jinlu, E-mail: buqc@mail.bnu.edu.cn, E-mail: tomaso.belloni@brera.inaf.it, E-mail: chenli@bnu.edu.cn, E-mail: qujl@ihep.ac.cn. Low Frequency Quasi-periodic Oscillations in the High-eccentric LMXB Cir X-1: Extending the WK Correlation for Z Sources. United States: N. p., 2017. Web. doi:10.3847/1538-4357/AA7068.
Bu, Qingcui, Chen, Li, Belloni, T. M., & Qu, Jinlu, E-mail: buqc@mail.bnu.edu.cn, E-mail: tomaso.belloni@brera.inaf.it, E-mail: chenli@bnu.edu.cn, E-mail: qujl@ihep.ac.cn. Low Frequency Quasi-periodic Oscillations in the High-eccentric LMXB Cir X-1: Extending the WK Correlation for Z Sources. United States. doi:10.3847/1538-4357/AA7068.
Bu, Qingcui, Chen, Li, Belloni, T. M., and Qu, Jinlu, E-mail: buqc@mail.bnu.edu.cn, E-mail: tomaso.belloni@brera.inaf.it, E-mail: chenli@bnu.edu.cn, E-mail: qujl@ihep.ac.cn. Thu . "Low Frequency Quasi-periodic Oscillations in the High-eccentric LMXB Cir X-1: Extending the WK Correlation for Z Sources". United States. doi:10.3847/1538-4357/AA7068.
@article{osti_22663543,
title = {Low Frequency Quasi-periodic Oscillations in the High-eccentric LMXB Cir X-1: Extending the WK Correlation for Z Sources},
author = {Bu, Qingcui and Chen, Li and Belloni, T. M. and Qu, Jinlu, E-mail: buqc@mail.bnu.edu.cn, E-mail: tomaso.belloni@brera.inaf.it, E-mail: chenli@bnu.edu.cn, E-mail: qujl@ihep.ac.cn},
abstractNote = {Using archival Rossi X-ray Timing Explorer ( RXTE ) data, we studied the low-frequency quasi-periodic oscillations (LFQPOs) in the neutron star low-mass X-ray binary (LMXB) Cir X-1 and examined their contribution to frequency–frequency correlations for Z sources. We also studied the orbital phase effects on the LFQPO properties and found them to be phase independent. Comparing LFQPO frequencies in different classes of LMXBs, we found that systems that show both Z and atoll states form a common track with atoll/BH sources in the so-called WK correlation, while persistent Z systems are offset by a factor of about two. We found that neither source luminosity nor mass accretion rate is related to the shift of persistent Z systems. We discuss the possibility of a misidentification of fundamental frequency for horizontal branch oscillations from persistent Z systems and interpreted the oscillations in terms of models based on relativistic precession.},
doi = {10.3847/1538-4357/AA7068},
journal = {Astrophysical Journal},
number = 2,
volume = 841,
place = {United States},
year = {Thu Jun 01 00:00:00 EDT 2017},
month = {Thu Jun 01 00:00:00 EDT 2017}
}