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

Observations LPA: ± 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 = 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

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

Large Phased Array

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

PSR B

Mean profiles at frequency 111 MHz Malov, Malofeev, 2008

Mean profiles of the PSR B

Suspicion of interpulse

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

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  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

Conclusions  W  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