Mean pulse profiles and Mean pulse profiles and spectra at the low spectra at the low frequenciesfrequencies
Malov O.I., Malofeev V.M.Malov O.I., Malofeev V.M.
Pushchino Radio Astronomy Observatory
ObservationsObservations
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
Receiver requirementsReceiver requirements
(d/dt)/t – instant bandwidth
scint – decorrelation bandwidth
< DM – dispersion broadening
F – Faraday effect
Data processingData processingSearching 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 = (DCdiagt)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
Dipole modelDipole modelr/sin2 = rLC - the last open field line
(r/rLC)1/2 = (2r/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/2mec
B r - 3 c r - 3 r c - 1/3
(r/rLC)1/2 r1/2 c - 1/6
ConclusionsConclusions 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