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

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Presentation on theme: "Mean pulse profiles and spectra at the low frequencies Malov O.I., Malofeev V.M. Malov O.I., Malofeev V.M. Pushchino Radio Astronomy Observatory."— Presentation transcript:

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

2 Observations LPA: 111.5 ± 1.5 МHz, 3.5 m / cos , A ef  3  10 4 cos  -55  m 2 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

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6 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 = (DC diag  t)  t1 t2 I(t)/NI o D – calibration factor, equal to step amplitude in Jy C diag – correction factor taking into account the complex shape of diagram  t – sampling interval I and I o – the amplitudes of pulse signal and step in units of ACC t 1 and t 2 – the boundaries of the summed pulse

7 PSR B1112+50

8 Mean profiles at frequency 111 MHz Malov, Malofeev, 2008

9 Mean profiles of the PSR B0643+80

10 Suspicion of interpulse

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

13 Dipole model r/sin 2  = r LC - the last open field line   (r/r LC ) 1/2 = (2  r/cP) 1/2  (r/P) 1/2 p 2 = n e e 2 /  m e  p  n 1/2  r - 3/2 for dipole field r  - 2/3    - 1/3 We obtained W  - 0.17 c = eB/2  m e c B  r - 3  c  r - 3  r  c - 1/3   (r/r LC ) 1/2    r 1/2  c - 1/6

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17 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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