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Published byReynold Campbell Modified over 9 years ago
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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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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
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Receiver requirements (d /dt)/ t – instant bandwidth scint – decorrelation bandwidth < DM – dispersion broadening F – Faraday effect
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Large Phased Array
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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
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PSR B1112+50
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Mean profiles at frequency 111 MHz Malov, Malofeev, 2008
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Mean profiles of the PSR B0643+80
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Suspicion of interpulse
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lg W 10 = (-0.45 0.08) lg P + (1.37 0.03) K = -0.53 0.09
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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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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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