The Crab Nebula and its pulsar PSR B0531 + 21 is the space laboratory for the study of fundamental physical processes. From the beginning of the current century up to date, the giant pulses of the pulsar in the Crab Nebula are regularly observed on the Large Phased Array of the Pushchino Radio Astronomy Observatory of the Lebedev Physical Institute at a frequency 111 MHz. The connection between the scattering time scale of radio pulses and the dispersion measure of the pulsar, which was established earlier together with Jodrell Bank, is confirmed. The observed variations in the scattering of radio pulses and their partial correlation with the dispersion measure are explained by the eclipse of the pulsar by dense plasma clouds with fluctuations in the electron density significantly exceeding the corresponding fluctuations in the interstellar medium. The question of a possible connection between period failers (glitches), dispersion measure variations, radio pulses scattering and gamma-ray flares is discussed.
References
[1]
Buhler, R. and Blandford, R. (2014) The Surprising Crab Pulsar and Its Nebula: A Review. Reports on Progress in Physics, 77, Article ID: 066901. https://doi.org/10.1088/0034-4885/77/6/066901
[2]
Staelin, D.H. and Reifenstein, E.C. (1968) Pulsating Radio Sources near the Crab Pulsar Nebula. Science, 162, 1481-1483. https://doi.org/10.1126/science.162.3861.1481
[3]
Rankin, J.M. and Counselman, C.C. (1973) Pulsar NP 0532: Variability of Dispersion and Scattering. The Astrophysical Journal, 181, 875-889. https://doi.org/10.1086/152099
[4]
Isaacman, R. and Rankin, J.M. (1977) The Crab Nebula Pulsar: Variability of Dispersion and Scattering. The Astrophysical Journal, 214, 214-232. https://doi.org/10.1086/155245
[5]
Kuz’min, A.D., Belyatsky, Yu.A., Dumsky, D.V., Izvekova, V.A., Lapaev, K.A., Logvinenko, S.V., Losovsky, B.Ya. and Pugachev, V.D. (2012) Monitoring of the Radio Emission of the Crab Nebula Pulsar at Low Frequencies. Astronomy Reports, 55, 416-424. https://doi.org/10.1134/S1063772911040032
[6]
Losovsii, B.Ya. (2017) The Dynamics and Structure of Plasma Inhomogeneities in the Crab Nebula. Astronomy Reports, 61, 187-192. https://doi.org/10.1134/S1063772917030052
[7]
Losovsky, B.Ya., Dumsky, D.V. and Belyatsky, Yu.A. (2019) Relationship between Scattering and Dispersion Measure of the Crab Nebula Pulsar. Astronomy Reports, 63, 830-834. https://doi.org/10.1134/S1063772919090051
[8]
Alurkar, S.K., Slee, O.B. and Bobra, A.D. (1986) Scattering of Pulsar Radiation and Electron Density Turbulence in the Interstellar Medium. Australian Journal of Physics, 39, 433-448. https://doi.org/10.1071/PH860433
[9]
Kuzmin, A., Losovsky, B.Ya., Jordan, C.A. and Graham-Smith, F. (2008) Correlation of the Scattering and Dispersion Events in the Crab Nebula Pulsar. Astronomy & Astrophysics, 483, 13-14. https://doi.org/10.1051/0004-6361:20079211
[10]
Manchester, R. (1977) Taylor J. Pulsars. Freeman, San Francisco; Moscow, 1980.
[11]
Abdo, A.A., Ackermann, M., Ajello, M., et al. (2011) Gamma-Ray Flares from the Crab Nebula. Science, 331, 739-755.
[12]
Ojha, R., Hays, E., Buehle, R. and Dutka, M. (2013) Fermi LAT Detection of a New Gamma-Ray Flare from the Crab Nebula Region. Atel, 4855.
[13]
Buehler, R., Scargle, J.D., Blandford, R.D., et al. (2012) Gamma-Ray Activity in the Crab Nebula. The Exceptional Flare of 2011 April. The Astrophysical Journal, 749, 26. https://doi.org/10.1088/0004-637X/749/1/26
[14]
Tavani, M., Bulgarelli, A., Vittorini, V., et al. (2011) Discovery of Powerful Gamma-Ray Flares from the Crab Nebula. Science, 331, 736-759.
[15]
Striani, E., Tavani, M., Vittorini, V., et al. (2013) Variable Gamma-Ray Emission from the Crab Nebula: Short Flares and Long “Waves”. The Astrophysical Journal, 765, 52S. https://doi.org/10.1088/0004-637X/765/1/52
[16]
Bulgarelli, A., Tavani, M., Parmiggiani, N., et al. (2018) AGILE Detection of Renewed Gamma-Ray Activity from Crab Nebula. Atel, 12148.
[17]
Huang, X., Yuan, Q. and Fan, Y. (2021) Ray Flares from the Crab Nebula with Fermi-LAT. The Astrophysical Journal, 908, 65.
[18]
McKee, J.W., Lyne, A.G., Stappers, B.W., Bassa, C.G. and Jordan, C.A. (2018) Temporal Variations in Scattering and Dispersion Measure in the Crab Pulsar and Their Effect on Timing Precision. Monthly Notices of the Royal Astronomical Society, 479, 4216-4224. https://doi.org/10.1093/mnras/sty1727
[19]
Kuzmin, A.D. and Losovsky, B.Ya. (1999) Observations of the Mean Profiles of Radio Pulsar and the Structure of Their Emitting Regions at 102 MHz. Astronomy Reports, 43, 288-304.
[20]
Cordes, J.M., Weisberg, J.M. and Boriakoff, V. (1985) Small-Scale Electron Density Turbulence in the Interstellar Medium. The Astrophysical Journal, 288, 221-247. https://doi.org/10.1086/162784
[21]
Kuzmin, A.D., Kondrat’ev, V.I., Kostyuk, S.V., Losovsky, B.Ya., Popov, M.V., Soglasnov, V.F., D’Amico, N. and Montebugnoli, S. (2002) Frequency Dependence of the Scattering Pulse Broadening for Crab Pulsar. Astronomy Letters, 28, 251-256. https://doi.org/10.1134/1.1467260
[22]
Yao, J.M., Manchester, R.N. and Wang, N. (2017) A New Electron-Density Model for Estimation of Pulsar and FRB Distances. The Astrophysical Journal, 835, 29-59. https://doi.org/10.3847/1538-4357/835/1/29
[23]
Kuzmin, A.D., Losovsky, B.Ya., Logvinenko, S.V. and Litvinov, I.I. (2008) Deviation of the Arrival-Time Delay of Pulses from the Crab Pulsar from the Quadratic Frequency Relation. Astronomy Reports, 52, 910-916. https://doi.org/10.1134/S106377290811005X
[24]
Espinoza, C.M., Lyne, A.G., Stappers, B.W. and Kramer, M. (2011) A Study of 315 Glitches in the Rotation of 102 Pulsars. Monthly Notices of the Royal Astronomical Society, 414, 1679-1704. https://doi.org/10.1111/j.1365-2966.2011.18503.x
[25]
Cadez, A., Zampiery, L., Barbiery, C., Calvani, M., Naletto, G., Barbiery, M. and Ponikwar, D. (2016) What Brakes the Crab Pulsar. Astronomy & Astrophysics, 587, A99. https://doi.org/10.1051/0004-6361/201526490
[26]
Lyne, A.G., Jordan, C.A., Graham-Smith, F., Espinoza, C.M., Stappers, B.W. and Weltevrede, P. (2015) 45 Years of the Rotation of the Crab Pulsar. Monthly Notices of the Royal Astronomical Society, 446, 857-864. https://doi.org/10.1093/mnras/stu2118
[27]
Kou, F.F. and Tong, H. (2015) Rotational Evolution of the Crab Pulsar in the Wind Braking Model. Monthly Notices of the Royal Astronomical Society, 450, 1990-1998. https://doi.org/10.1093/mnras/stv734
[28]
Striani, E., Tavani, M., Vittorini, V., et al. (2013) Variable Gamma-Ray Emission from the Crab Nebula: Short Flares and Long “Waves”. The Astrophysical Journal, 765, 52-62. https://doi.org/10.1088/0004-637X/765/1/52
