Skip to main content
SpringerLink
Log in

Optical observations of Scorpius X-1 in 2008: Evidence of rapid variability

  • Research Papers
  • Published:
Science China Physics, Mechanics and Astronomy Aims and scope Submit manuscript

Abstract

Optical observations of Sco X-1 with exposure times around 0.5 s were performed with the 1.56 m telescope of the Shanghai Astronomical Observatory in 2008. With these observations, we studied the fluctuation of the optical flux on three short timescales (5, 10, 100 s). We found that the standard deviations of fluctuations on these three timescales differ from those of Gaussian distributions by 7 Sigma, 5 Sigma and 3 Sigma, respectively. The result suggests that the variations in the intensity on these short timescales differ from pure statistical fluctuations, which, we suggest, is due to the intrinsic variability in the optical emission.

This is a preview of subscription content, log in via an institution to check access.

Access this article

Log in via an institution

Price excludes VAT (USA)
Tax calculation will be finalised during checkout.

Instant access to the full article PDF.

Institutional subscriptions

Similar content being viewed by others

References

  1. Hasinger G, van der Klis M. Two patterns of correlated X-ray timing and spectral behaviour in low-mass X-ray binaries. Astron Astrophys, 1989, 225: 79–96

    ADS  Google Scholar 

  2. Vrtilek S D, Penninx W, Raymond J C, et al. Observations of Scorpius X-1 with IUE — Ultraviolet results from a multiwavelength campaign. Astrophys J, 1991, 376: 278–288

    Article  ADS  Google Scholar 

  3. Raymond J C. A model of an X-ray-illuminated accretion disk and corona. Astrophys J, 1993, 412: 267–277

    Article  ADS  Google Scholar 

  4. Steeghs D, Casares J. The mass donor of Scorpius X-1 revealed. Astrophys J, 2002, 568: 273–278

    Article  ADS  Google Scholar 

  5. Muñoz-Darias T, Martínez-Pais I G, Casares J, et al. Multiband echo tomography of Sco X-1. Adv Space Res, 2006, 38: 2762–2764

    Article  ADS  Google Scholar 

  6. Muñoz-Darias T, Martínez-Pais I G, Casares J, et al. Echoes from the companion star in Sco X-1. Mon Not Roy Astron Soc, 2007, 379: 1637–1646

    Article  ADS  Google Scholar 

  7. Mcnamara B J, Norwood J, Harrison T E, et al. Monitoring the mass accretion rate in Scorpius X-1 using the optical Johnson B filter. Astrophys J, 2005, 623: 1070–1075

    Article  ADS  Google Scholar 

  8. Evans W D, Belian R D, Conner J P, et al. X-ray and optical variations of Scorpius X-1. Astrophys J, 1970, 162: L115–L119

    Article  ADS  Google Scholar 

  9. Pelling M R. Long-term X-ray observations of Scorpius X-1 by Oso-Iii. Astrophys J, 1973, 185: 327–334

    Article  ADS  Google Scholar 

  10. Bradt H V, Moore G, Braes L L E. The X-ray, optical, and radio behavior of Scorpius X-1 — The 1971 coordinated observations. Astrophys J, 1975, 197: 443–455

    Article  ADS  Google Scholar 

  11. Mook D E, Messina R J, Hiltner W A, et al. Results of X-ray and optical monitoring of Scorpius X-1 in 1970. Astrophys J, 1975, 197: 425–441

    Article  ADS  Google Scholar 

  12. Hudson H S, Peterson L E, Schwartz D A. Simultaneous X-ray and optical observations of Sco X-1 flares. Astrophys J, 1970, 159: L51–L56

    Article  ADS  Google Scholar 

  13. Canizares C R, Clark G M, Li F K, et al. The X-ray, optical, and radio behavior of Scopius X-1 — The 1972 coordinated observations. Astrophys J, 1975, 197: 457–466

    Article  ADS  Google Scholar 

  14. IIovaisky S A, Chevalier C, White N E, et al. Simultaneous X-ray and optical observations of rapid variability in Scorpius X-1. Mon Not Roy Astron Soc, 1980, 191: 81–93

    ADS  Google Scholar 

  15. Mcnamara B J, Harrison T E, Zavala R T, et al. The behavior of the optical and X-ray emission from Sco X-1. Astrophys J, 2003, 125: 1437–1443

    Google Scholar 

  16. van der Klis M. Rapid X-ray variability. In: Walter L, van der Klis M, eds. Compact stellar X-ray Sources. Dordrecht: Cambridge University Press, 2006, 39. 39–112

    Chapter  Google Scholar 

  17. Cao X F, Yu W F. Frequency variation of the kilohertz quasi-periodic oscillations and the flux of the band-limited noise in Scorpius X-1. Astrophys J, 2009, 690: 1363–1369

    Article  ADS  Google Scholar 

  18. Yu W F, van der Klis M, Jonker P G. Dependence of Kilohertz quasi-periodic oscillation properties on the normal-branch oscillation phase in Scorpius X-1. Astrophys J, 2001, 559: L29–L32

    Article  ADS  Google Scholar 

  19. Bildsten L. Propagation of nuclear burning fronts on accreting neutron star: X-ray and sub-hertz noise. Astrophys J, 1995, 438: 852–875

    Article  ADS  Google Scholar 

Download references

Author information

Authors and Affiliations

  1. Shanghai Astronomical Observatory, Shanghai, 200030, China

    XiaoFeng Cao, WenFei Yu, Zhen Yan & Li Sun

  2. Institute of Astrophysics, Huazhong Normal University, Wuhan, 430079, China

    XiaoFeng Cao

Authors
  1. XiaoFeng Cao
    View author publications

    You can also search for this author in PubMed Google Scholar

  2. WenFei Yu
    View author publications

    You can also search for this author in PubMed Google Scholar

  3. Zhen Yan
    View author publications

    You can also search for this author in PubMed Google Scholar

  4. Li Sun
    View author publications

    You can also search for this author in PubMed Google Scholar

Corresponding author

Correspondence to WenFei Yu.

Additional information

This work was supported by the National Natural Science Foundation of China (Grant Nos. 10773023, 10833002, 10773004, and 10603002), the One Hundred Talents Project of the Chinese Academy of Sciences, the Shanghai Pujiang Program (Grant No. 08PJ14111), the National Basic Research Program of China (Grant No. 2009CB824800), and the Starting Funds at the Shanghai Astronomical Observatory.

Rights and permissions

Reprints and permissions

About this article

Cite this article

Cao, X., Yu, W., Yan, Z. et al. Optical observations of Scorpius X-1 in 2008: Evidence of rapid variability. Sci. China Phys. Mech. Astron. 53 (Suppl 1), 143–146 (2010). https://doi.org/10.1007/s11433-010-0012-6

Download citation

  • Received:

  • Accepted:

  • Published:

  • Issue Date:

  • DOI: https://doi.org/10.1007/s11433-010-0012-6

Keywords

Search

Navigation