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Mean pulse profiles and spectra at the low frequencies

Mean pulse profiles and spectra at the low frequencies. Malov O.I., Malofeev V.M. Pushchino Radio Astronomy Observatory. Observations. LPA : 111. 5 ± 1.5 М Hz, 3.5 m / cos , A ef  3  10 4 cos-55 m 2 Receivers : 128  20 kHz, 32  5 kHz, 128  1.25 kHz

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Mean pulse profiles and spectra at the low frequencies

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  1. Mean pulse profiles and spectra at the low frequencies Malov O.I., Malofeev V.M. Pushchino Radio Astronomy Observatory

  2. Observations • LPA: 111.5 ± 1.5 МHz, 3.5 m / cos , Aef  3  104 cos-55 m2 • Receivers: 128  20 kHz, 32  5 kHz, 128  1.25 kHz t = 1.28 ms, 2.56 ms, 5.12 ms for normal PSRs t = 0.3072 ms for millisecond PSRs • Calibration: discrete sources with known flux density step of the noise generator 40 ms for normal PSRs 4 ms for millisecond ones

  3. Receiver requirements •   (d/dt)/t – instant bandwidth •   scint – decorrelation bandwidth •  < DM – dispersion broadening •   F – Faraday effect

  4. Large Phased Array

  5. Data processing • Searching for the “zero” level • Gain equalization • Elimination of channels with interference • Summation of the signal over the channels • Searching for the new “zero” line E = (DCdiagt)t1t2I(t)/NIo D – calibration factor, equal to step amplitude in Jy Cdiag – correction factor taking into account the complex shape of diagram t – sampling interval I and Io – the amplitudes of pulse signal and step in units of ACC t1 and t2 – the boundaries of the summed pulse

  6. PSR B1112+50

  7. Mean profiles at frequency 111 MHz Malov, Malofeev, 2008

  8. Mean profiles of the PSR B0643+80

  9. Suspicion of interpulse

  10. lg W10= (-0.450.08) lg P + (1.370.03) K = -0.53  0.09

  11. Dipole model r/sin2 = rLC - the last open field line   (r/rLC)1/2 = (2r/cP)1/2  (r/P)1/2 p2 = nee2/ me  p n1/2  r - 3/2 for dipole field r  - 2/3    - 1/3 We obtained W  - 0.17 c = eB/2mec B  r -3  c  r - 3  r  c- 1/3   (r/rLC)1/2    r1/2 c- 1/6

  12. Conclusions • W  - 0.17 probably means that the emission generation takes place at the cyclotron frequency • We constructed spectra for normal and millisecond pulsars using our measurements. About 30% of normal pulsars have a low frequency turn-over. Most of millisecond pulsars (about 95%) have linear spectra

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