Skip to main content
Log in

Long-term variations of X-ray pulse profiles for the Crab pulsar: data analysis and modeling

  • Article
  • Published:
Science China Physics, Mechanics & Astronomy Aims and scope Submit manuscript

Abstract

The pulse profiles of the Crab pulsar (as well as some other pulsars) vary with time. They can lead to a major source of intrinsic timing noise, which lacks a detailed physical model. The phase separation Δ between the first left peak (P1) and the second right peak (P2) is a key parameter that shows the variations of pulse profiles for the Crab pulsar. It was found that the evolution of A has a tendency with increasing rates of 0.82° ± 0.25°, 0.80° ± 0.54°, and 0.77° ± 0.28° per century for the 2–6, 6–15, and 15–60 keV bands, respectively. Furthermore, the flux ratios (P2/P1) of X-ray pulse profiles in the three bands were calculated, and the derived flux ratios were consistent with the radio and X-ray measurements of the Insight-HXMT. In addition to discovering the physical origin of the pulse changes, the high-SNR X-ray pulse profiles were simulated in the annular gap model, and two model parameters (e.g., the maximum emission heights of the two peaks) were observed to slightly affect the variations of peak separation. We fitted the long-term variations of emission heights of the two peaks and discovered that the emission heights showed increasing tendencies with time. Variations of these emission heights induced a characteristic period derivative, and a complete formula for both the magnetic dipole radiation and wind-particle-induced variations of the moment of inertia was used for the pulsar’s spin-down to obtain the variation rate ά of the magnetic inclination angle, which was −1.60° per century. Intrinsic timing noise is observed to be mainly induced by the variations of pulse profiles, which might correlate with a characteristic spin period derivative arising from the fluctuations of the emission regions. This work will lay a foundation for understanding the origin of intrinsic timing noise and making high-precision timing models in the future.

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

Access this article

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

Instant access to the full article PDF.

Similar content being viewed by others

References

  1. R. N. Manchester, G. B. Hobbs, A. Teoh, and M. Hobbs, Astron. J. 129, 1993 (2005), arXiv: astro-ph/0412641.

    ADS  Google Scholar 

  2. M. A. Livingstone, V. M. Kaspi, F. P. Gavriil, and R. N. Manchester, Astrophys. J. 619, 1046 (2005), arXiv: astro-ph/0410361.

    ADS  Google Scholar 

  3. A. Lyne, G. Hobbs, M. Kramer, I. Stairs, and B. Stappers, Science 329, 408 (2010), arXiv: 1006.5184.

    ADS  Google Scholar 

  4. A. Lyne, F. Graham-Smith, P. Weltevrede, C. Jordan, B. Stappers, C. Bassa, and M. Kramer, Science 342, 598 (2013), arXiv: 1311.0408.

    ADS  Google Scholar 

  5. M. Y. Ge, F. J. Lu, J. L. Qu, S. J. Zheng, Y. Chen, and D. W. Han, Astrophys. J. Suppl. Ser. 199, 32 (2012), arXiv: 1204.2199.

    ADS  Google Scholar 

  6. M. Y. Ge, L. L. Yan, F. J. Lu, S. J. Zheng, J. P. Yuan, H. Tong, S. N. Zhang, and Y. Lu, Astrophys. J. 818, 48 (2016), arXiv: 1909.04809.

    ADS  Google Scholar 

  7. J. S. Deneva, P. S. Ray, A. Lommen, S. M. Ransom, S. Bogdanov, M. Kerr, K. S. Wood, Z. Arzoumanian, K. Black, J. Doty, K. C. Gendreau, S. Guillot, A. Harding, N. Lewandowska, C. Malacaria, C. B. Markwardt, S. Price, L. Winternitz, M. T. Wolff, L. Guillemot, I. Cognard, P. T. Baker, H. Blumer, P. R. Brook, H. T. Cromartie, P. B. Demorest, M. E. DeCesar, T. Dolch, J. A. Ellis, R. D. Ferdman, E. C. Ferrara, E. Fonseca, N. Garver-Daniels, P. A. Gentile, M. L. Jones, M. T. Lam, D. R. Lorimer, R. S. Lynch, M. A. McLaughlin, C. Ng, D. J. Nice, T. T. Pennucci, R. Spiewak, I. H. Stairs, K. Stovall, J. K. Swiggum, S. J. Vigeland, and W. W. Zhu, Astrophys. J. 874, 160 (2019), arXiv: 1902.07130.

    ADS  Google Scholar 

  8. T. Wong, D. C. Backer, and A. G. Lyne, Astrophys. J. 548, 447 (2001), arXiv: astro-ph/0010010.

    ADS  Google Scholar 

  9. Z. Arzoumanian, K. C. Gendreau, C. L. Baker, T. Cazeau, P. Hestnes, J. W. Kellogg, S. J. Kenyon, R. P. Kozon, K.-C. Liu, S. S. Manthripragada, C. B. Markwardt, A. L. Mitchell, J. W. Mitchell, C. A. Monroe, T. Okajima, S. E. Pollard, D. F. Powers, B. J. Savadkin, L. B. Winternitz, P. T. Chen, M. R. Wright, R. Foster, G. Prigozhin, R. Remillard, and J. Doty, Proc. SPIE 9144, 914420 (2014).

    Google Scholar 

  10. K. Gendreau, and Z. Arzoumanian, Nat. Astron. 1, 895 (2017).

    ADS  Google Scholar 

  11. K. Jahoda, J. H. Swank, A. B. Giles, M. J. Stark, T. Strohmayer, W. W. Zhang, and E. H. Morgan, Int. Soc. Opt. Photon. 2808, 59 (1996).

    Google Scholar 

  12. D. E. Gruber, P. R. Blanco, W. A. Heindl, M. R. Pelling, R. E. Rothschild, and P. L. Hink, Astron. Astrophys. Suppl. Ser. 120, 641 (1996).

    ADS  Google Scholar 

  13. K. Jahoda, C. B. Markwardt, Y. Radeva, A. H. Rots, M. J. Stark, J. H. Swank, T. E. Strohmayer, and W. Zhang, Astrophys. J. Suppl. Ser. 163, 401 (2006), arXiv: astro-ph/0511531.

    ADS  Google Scholar 

  14. T. P. Li, et al. (The Insight-HXMT team) Sci. China-Phys. Mech. Astron. 61, 031011 (2018), arXiv: 1710.06065.

    ADS  Google Scholar 

  15. F. Özel, D. Psaltis, Z. Arzoumanian, S. Morsink, and M. Bauböck, Astrophys. J. 832, 92 (2016), arXiv: 1512.03067.

    ADS  Google Scholar 

  16. T. Okajima, Y. Soong, E. R. Balsamo, T. Enoto, L. Olsen, R. Koenecke, L. Lozipone, J. Kearney, S. Fitzsimmons, A. Numata, S. J. Kenyon, Z. Arzoumanian, and K. Gendreau, Proc. SPIE 9905, 99054X (2016).

  17. B. LaMarr, G. Prigozhin, R. Remillard, A. Malonis, K. C. Gendreau, Z. Arzoumanian, C. B. Markwardt, and W. H. Baumgartner, Proc. SPIE 9905, 99054W (2016).

    ADS  Google Scholar 

  18. A. Sanna, C. Ferrigno, P. S. Ray, L. Ducci, G. K. Jaisawal, T. Enoto, E. Bozzo, D. Altamirano, T. Di Salvo, T. E. Strohmayer, A. Papitto, A. Riggio, L. Burderi, P. M. Bult, S. Bogdanov, A. F. Gambino, A. Marino, R. Iaria, Z. Arzoumanian, D. Chakrabarty, K. C. Gendreau, S. Guillot, C. Markwardt, and M. T. Wolff, Astron. Astrophys. 617, L8 (2018), arXiv: 1808.10195.

    ADS  Google Scholar 

  19. X. Zhang, P. Shuai, L. Huang, S. Chen, and L. Xu, Int. J. Aerospace Eng. 2017(1), 1 (2017).

    ADS  Google Scholar 

  20. A. G. Lyne, R. S. Pritchard, and F. Graham Smith, Mon. Not. R. Astron. Soc. 265, 1003 (1993).

    ADS  Google Scholar 

  21. X. Zhang, and A. P. Showman, Astrophys. J. 866, 2 (2018), arXiv: 1808.05365.

    ADS  Google Scholar 

  22. J. Nelson, R. Hills, D. Cudaback, and J. Wampler, Astrophys. J. 161, L235 (1970).

    ADS  Google Scholar 

  23. Y. L. Tuo, M. Y. Ge, L. M. Song, L. L. Yan, Q. C. Bu, and J. L. Qu, Res. Astron. Astrophys. 19, 087 (2019), arXiv: 1906.03633.

    ADS  Google Scholar 

  24. G. J. Qiao, K. J. Lee, H. G. Wang, R. X. Xu, and J. L. Han, Astrophys. J. 606, L49 (2004), arXiv: astro-ph/0403398.

    ADS  Google Scholar 

  25. G. J. Qiao, K. J. Lee, B. Zhang, R. X. Xu, and H. G. Wang, Astrophys. J. 616, L127 (2004), arXiv: astro-ph/0410479.

    ADS  Google Scholar 

  26. G. J. Qiao, K. J. Lee, B. Zhang, H. G. Wang, and R. X. Xu, Chin. J. Astron. Astrophys. 7, 496 (2007).

    ADS  Google Scholar 

  27. Y. J. Du, G. J. Qiao, J. L. Han, K. J. Lee, and R. X. Xu, Mon. Not. R. Astron. Soc. 406, 2671 (2010), arXiv: 1004.3213.

    ADS  Google Scholar 

  28. Y. J. Du, J. L. Han, G. J. Qiao, and C. K. Chou, Astrophys. J. 731, 2 (2011), arXiv: 1102.2476.

    ADS  Google Scholar 

  29. Y. J. Du, G. J. Qiao, and W. Wang, Astrophys. J. 748, 84 (2012), arXiv: 1202.1096.

    ADS  Google Scholar 

  30. P. Goldreich, and W. H. Julian, Astrophys. J. 157, 869 (1969).

    ADS  Google Scholar 

  31. M. A. Ruderman, and P. G. Sutherland, Astrophys. J. 196, 51 (1975).

    ADS  Google Scholar 

  32. A. G. Lyne, C. A. Jordan, F. Graham-Smith, C. M. Espinoza, B. W. Stappers, and P. Weltevrede, Mon. Not. R. Astron. Soc. 446, 857 (2015), arXiv: 1410.0886.

    ADS  Google Scholar 

  33. A. K. Harding, M. G. Baring, and P. L. Gonthier, Astron. Astrophys. 120, 111 (1996).

    ADS  Google Scholar 

  34. A. N. Timokhin, and A. K. Harding, Astrophys. J. 810, 144 (2015), arXiv: 1504.02194.

    ADS  Google Scholar 

  35. H. Tong, Sci. China-Phys. Mech. Astron. 59, 619501 (2016), arXiv: 1506.04605.

    Google Scholar 

  36. J. G. Lu, Y. J. Du, L. F. Hao, Z. Yan, Z. Y. Liu, K. J. Lee, G. J. Qiao, L. H. Shang, M. Wang, R. X. Xu, Y. L. Yue, and Q. J. Zhi, Astrophys. J. 816, 76 (2016), arXiv: 1511.08298.

    ADS  Google Scholar 

  37. L. H. Shang, J. G. Lu, Y. J. Du, L. F. Hao, D. Li, K. J. Lee, B. Li, L. X. Li, G. J. Qiao, Z. Q. Shen, D. H. Wang, M. Wang, X. J. Wu, Y. J. Wu, R. X. Xu, Y. L. Yue, Z. Yan, Q. J. Zhi, R. B. Zhao, and R. S. Zhao, Mon. Not. R. Astron. Soc. 468, 4389 (2017), arXiv: 1703.03582.

    ADS  Google Scholar 

  38. G. Hobbs, A. G. Lyne, and M. Kramer, Mon. Not. R. Astron. Soc. 402, 1027 (2010), arXiv: 0912.4537.

    ADS  Google Scholar 

  39. P. R. Brook, A. Karastergiou, S. Johnston, M. Kerr, R. M. Shannon, and S. J. Roberts, Mon. Not. R. Astron. Soc. 456, 1374 (2016), arXiv: 1511.05481.

    ADS  Google Scholar 

  40. M. Kerr, G. Hobbs, S. Johnston, and R. M. Shannon, Mon. Not. R. Astron. Soc. 455, 1845 (2016), arXiv: 1510.06078.

    ADS  Google Scholar 

  41. M. J. Keith, R. M. Shannon, and S. Johnston, Mon. Not. R. Astron. Soc. 432, 3080 (2013), arXiv: 1304.4644.

    ADS  Google Scholar 

  42. J. Zhao, C. W. Ng, L. C. C. Lin, J. Takata, Y. Cai, C. P. Hu, D. C. C. Yen, P. H. T. Tam, C. Y. Hui, A. K. H. Kong, and K. S. Cheng, Astrophys. J. 842, 53 (2017), arXiv: 1706.00236.

    ADS  Google Scholar 

  43. J. Palfreyman, J. M. Dickey, A. Hotan, S. Ellingsen, and W. van Straten, Nature 556, 219 (2018).

    ADS  Google Scholar 

  44. F. F. Kou, J. P. Yuan, N. Wang, W. M. Yan, and S. J. Dang, Mon. Not. R. Astron. Soc.-Lett. 478, L24 (2018), arXiv: 1801.01248.

    ADS  Google Scholar 

  45. R. E. Packard, Phys. Rev. Lett. 28, 1080 (1972).

    ADS  Google Scholar 

  46. P. W. Anderson, and N. Itoh, Nature 256, 25 (1975).

    ADS  Google Scholar 

  47. M. Ruderman, Astrophys. J. 203, 213 (1976).

    ADS  Google Scholar 

  48. M. A. Alpar, R. Nandkumar, and D. Pines, Astrophys. J. 311, 197 (1986).

    ADS  Google Scholar 

  49. P. B. Jones, Mon. Not. R. Astron. Soc. 246, 364 (1990).

    ADS  Google Scholar 

  50. G. Greenstein, Nature 227, 791 (1970).

    ADS  Google Scholar 

  51. A. Melatos, and B. Link, Mon. Not. R. Astron. Soc. 437, 21 (2014), arXiv: 1310.3108.

    ADS  Google Scholar 

  52. S. Johnston, and D. Galloway, Mon. Not. R. Astron. Soc. 306, L50 (1999), arXiv: astro-ph/9905058.

    ADS  Google Scholar 

  53. I. H. Stairs, A. G. Lyne, and S. L. Shemar, Nature 406, 484 (2000).

    ADS  Google Scholar 

  54. K. S. Cheng, Astrophys. J. 321, 799 (1987).

    ADS  Google Scholar 

  55. K. S. Cheng, Astrophys. J. 321, 805 (1987).

    ADS  Google Scholar 

  56. J. M. Cordes, and R. M. Shannon, Astrophys. J. 682, 1152 (2008), arXiv: astro-ph/0605145.

    ADS  Google Scholar 

  57. G. J. Qiao, Y. Q. Xue, R. X. Xu, H. G. Wang, and B. W. Xiao, Astron. Astrophys. 407, L25 (2003).

    ADS  Google Scholar 

  58. B. Shaw, B. W. Stappers, and P. Weltevrede, Mon. Not. R. Astron. Soc. 475, 5443 (2018), arXiv: 1801.05804.

    ADS  Google Scholar 

  59. A. Santangelo, Sci. China-Phys. Mech. Astron. 62, 029501 (2019).

    Google Scholar 

  60. A. D. Rosa, P. Uttley, L. J. Gou, Y. Liu, C. Bambi, D. Barret, T. Belloni, E. Berti, S. Bianchi, I. Caiazzo, P. Casella, M. Feroci, V. Ferrari, L. Gualtieri, J. Heyl, A. Ingram, V. Karas, F. J. Lu, B. Luo, G. Matt, S. Motta, J. Neilsen, P. Pani, A. Santangelo, X. W. Shu, J. F. Wang, J. M. Wang, Y. Q. Xue, Y. P. Xu, W. M. Yuan, Y. F. Yuan, S. N. Zhang, S. Zhang, I. Agudo, L. Amati, N. Andersson, C. Baglio, P. Bakala, A. Baykal, S. Bhattacharyya, I. Bombaci, N. Bucciantini, F. Capitanio, R. Ciolfi, W. K. Cui, F. DAmmando, T. Dauser, M. Del Santo, B. De Marco, T. Di Salvo, C. Done, M. Dovčiak, A. C. Fabian, M. Falanga, A. F. Gambino, B. Gendre, V. Grinberg, A. Heger, J. Homan, R. Iaria, J. C. Jiang, C. C. Jin, E. Koerding, M. Linares, Z. Liu, T. J. Maccarone, J. Malzac, A. Manousakis, F. Marin, A. Marinucci, M. Mehdipour, M. Méndez, S. Migliari, C. Miller, G. Miniutti, E. Nardini, P. T. OBrien, J. P. Osborne, P. O. Petrucci, A. Possenti, A. Riggio, J. Rodriguez, A. Sanna, L. J. Shao, M. Sobolewska, E. Sramkova, A. L. Stevens, H. Stiele, G. Stratta, Z. Stuchlik, J. Svoboda, F. Tamburini, T. M. Tauris, F. Tombesi, G. Torok, M. Urbanec, F. Vincent, Q. W. Wu, F. Yuan, J. J. M. in t Zand, A. A. Zdziarski, and X. L. Zhou, Sci. China-Phys. Mech. Astron. 62, 029504 (2019), arXiv: 1812.04022.

    Google Scholar 

  61. A. L. Watts, W. F. Yu, J. Poutanen, S. Zhang, S. Bhattacharyya, S. Bogdanov, L. Ji, A. Patruno, T. E. Riley, P. Bakala, A. Baykal, F. Bernardini, I. Bombaci, E. Brown, Y. Cavecchi, D. Chakrabarty, J. Chenevez, N. Degenaar, M. Del Santo, T. Di Salvo, V. Doroshenko, M. Falanga, R. D. Ferdman, M. Feroci, A. F. Gambino, M. Y. Ge, S. K. Greif, S. Guillot, C. Gungor, D. H. Hartmann, K. Hebeler, A. Heger, J. Homan, R. Iaria, J. Zand, O. Kargaltsev, A. Kurkela, X. Y. Lai, A. Li, X. D. Li, Z. S. Li, M. Linares, F. J. Lu, S. Mahmoodifar, M. Mendez, M. Coleman Miller, S. Morsink, J. Nättilä, A. Possenti, C. Prescod-Weinstein, J. L. Qu, A. Riggio, T. Salmi, A. Sanna, A. Santangelo, H. Schatz, A. Schwenk, L. M. Song, E. Šráová, B. Stappers, H. Stiele, T. Strohmayer, I. Tews, L. Tolos, G. Török, D. Tsang, M. Urbanec, A. Vacchi, R. X. Xu, Y. P. Xu, S. Zane, G. B. Zhang, S. N. Zhang, W. D. Zhang, S. J. Zheng, and X. Zhou, Sci. China-Phys. Mech. Astron. 62, 029503 (2019), arXiv: 1812.04021.

    Google Scholar 

Download references

Author information

Authors and Affiliations

Authors

Corresponding author

Correspondence to YuanJie Du.

Rights and permissions

Reprints and permissions

About this article

Check for updates. Verify currency and authenticity via CrossMark

Cite this article

Shang, L., Du, Y., Cui, X. et al. Long-term variations of X-ray pulse profiles for the Crab pulsar: data analysis and modeling. Sci. China Phys. Mech. Astron. 63, 109511 (2020). https://doi.org/10.1007/s11433-019-1505-8

Download citation

  • Received:

  • Accepted:

  • Published:

  • DOI: https://doi.org/10.1007/s11433-019-1505-8

Keywords

Navigation