Документ взят из кэша поисковой машины. Адрес оригинального документа : http://www.astro.spbu.ru/sobolev100/sites/default/files/kazantsev.pdf Дата изменения: Mon Mar 14 13:37:05 2016 Дата индексирования: Sun Apr 10 02:57:39 2016 Кодировка: Поисковые слова: http www.arcetri.astro.it


Radio pulsars

strictly periodic signals

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B 10 G;E 10 V / cm
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Individual pulses and average profile of pulsar

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Average profiles of pulsars

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average energy distribution of pulses by phase of period.

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Histograms of individual pulses energy distribution of pulsars

(Hesse & Wielebinski) , 1974 Excess of individual pulse's amplitude over amplitude of average profile typically can reach no more than ten times. 14.03.2016 5

2695


Giant pulses (GPs) of pulsar

Intensity, a.u.

Time, ms Pulses that exceed the average profile over 30 times were called giant pulses. 14.03.2016 6


First pulsars with GPs
Crab (B0531+21) P: 0.0331 s. DM: 56.791 cm-3pc. Discovery: 1968.

B1937+21 P: 0.0016 s. DM: 29.1168 cm-3pc. Discovery: 1984.

It should be noted that excess for these pulsars reach really giant values. 14.03.2016

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First pulsars with GPs
Pulsar in Crab nebulae (B0531+21) has most famous GPs.

The shortest ever observed component of GRP of the Crab pulsar (Hankins et al, 2003)
S 5 MJy Kalyazin (Russia), 2005, 2244 MHz, B = 16 MHz (Popov et al. 2005)

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Individual pulses energy distribution

1937+21. Cognard et al. 1996 The kink in distribution is around 30 times of average flux density
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0531+21. Popov et al., 2009
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Strong individual pulses tens, hundreds, thousands time as strong as averaged pulse. Peak flux density about hundreds, thousands and even millions Jy (when typical pulsar averaged pulse's flux is several Jy). Strong linear and circular polarization in pulse. E.g. ~60% GP of PSR B1937+21 are 100% circular polarized. GPs have a power law distribution both for peak flux and pulse's energy. Normal pulses have a Gaussian distribution on a logarithmic scale. GPs have short duration ­ up to several nanoseconds, e.g. B1937+21 (Soglasnov et al, 2004) GPs microstructure component may be as short as nanosecond or less, e.g. B0531+21 (Hankins et al., 2003). Extremely high brightness temperature: B0531+21 TB5в1037K; B1937+21 TB5в1039K
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«Classical» properties of GPs


List of pulsars with GRPs (2015 .)
Pulsar P, s P1, s/s Frequency, MHz DM, cm pc
-3

BLC, G

First note

J0034-0721
J0218+4232 J0534+2200 J0529-6652 J0540-6919 J0659+1414 J0953+0755 J1115+5030 B1237+25

0.9429
0.0023 0.0331 1.0249 0.0505 0.3849 0.2530 1.6564 1.38245

4.08e-16
7.73e-20 4.23e-13 7.73e-11 4.79e-13 5.50e-14 2.30e-16 2.49e-15 9.60e-16

40
610 40-8300 610 1390 111 111 111 111

11.380
61.252 56.791 103.20 146.500 13.977 2.958 9.195 9.242

7.02e+00
3.21e+05 9.80e+05 3.97e+01 3.62e+05 7.66e+02 1.41e+02 4.24e+00 4.14e+00

2004
2004 1968 2011 2006 2003 2003 2003 2014

J1752+2359
J1824-2452A J1823-3021A J1939+2134 J1959+2048

0.4091
0.0030 0.0054 0.0016 0.0016

0.64e-15
1.62e-18 3.38e-18 1.05e-19 1.69e-20

111
1510 685 111-5500 610

36.000
120.500 86.834 71.0398 29.1168

7.11e+01
7.41e+05 2.52e+05 1.02e+06 3.76e+05

2005
2001 2005 1984 2004 11

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The common physical model of the generation of the GPs is not available up to now.


Goal and tasks of research
· Goal: Search of the pulsar with GPs and investigation of their properties. · Tasks:
­ monitoring of pulsars during several years, ­ search in the collected data pulses which satisfy the main characteristics of GPs (exceed the average profile over 30 times and power law distribution for peak flux and pulse's energy).

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LPA of LPI radio telescope

Transit radio telescope. Phased array antenna. One linear polarization. Frequency: 111 MHz, Bandwidth: 2.3 MHz (460 x 5 kHz digital receiver with post-detector DM removal); Typical duration of one scan: 3 to 7 min. (e.g. B1237+21 - 3.53 min = 153 pulses); 14.03.2016 13



Objects of observations
50 pulsars = 8 pulsars (monitoring) + 42 pulsars (search)
PSR B0007+73 PSR B0711+74 PSR B1534+12 PSR B1919+21 PSR B203 0+36 PSR B0218+42 PSR B0809+74 PSR B1541+09 PSR B1929+10 PSR B2032+41

PSR B0031-07 PSR B0823+26 PSR B1652+26 PSR B1937+21 PSR B2055+25
PSR B0301+19 PSR B0834+06 PSR B1737+13 PSR B1946+35 PSR B2110+27 PSR B0320+39 PSR B0919+06 PSR B1752+23 PSR B1957+20 PSR B2111+46

PSR B0357+32 PSR B0950+08 PSR B1828-10 PSR B1957+50 PSR B2139+47
PSR B0450+55 PSR B1112+50 PSR B1836+59 PSR B2016+28 PSR B2154+40 PSR B0622+37 PSR B1133+16 PSR B1839+09 PSR B2020+28 PSR B2217+47

PSR B0643+80 PSR B1237+25 PSR B1846+09 PSR B2021+40 PSR B2310+42
PSR B0656+14 PSR B1508+55 PSR B1855+09 PSR B2028+33 PSR B2315+21
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Program of monitoring
PSR B1237+21 PSR B1112+50

PSR B0950+08

The monitoring program included pulsars which has been demonstrated GPs generation phenomenon previously

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Discovery of GPs of B1237+25
GPs from B1237+25 were discovered in 2014 by our group.

This phenomenon can be detected in all components of average profile.

(Kazantsev & Potapov, Astr.Tsirk., No.1620, 2015) 14.03.2016

f a 15 / 10000

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Individual pulses histograms for B1237+25

111 MHz

2695 MHz
K.H. Hesse & R. Wielebinski, 1974

Differs for histogram at 2695 MHz (no subpeaks). Much stronger in maximum

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GPs peak flux distribution (B1237+25)
Strongest GRP: S
max

= 900±200 Jy.

-1.26±0.05

-3.36±0.34

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(Kazantsev & Potapov, 2015)

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GPs B1112+50 monitoring
GPs from B1112+50 were discovered by Ershov&Kuzmin in 2003

GPs of B1112+50 distributions

14.03.2016 Ershov, Kuzmin, 2003

Kazantsev, Potapov, 2013

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GPs from B0950+08 were discovered by A.K. Singal // Astrophysics and Space Science, 2001, V.278, P.61

GRPs B0950+08 monitoring

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111 MHz

2695 MHz

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GPs peak flux distribution (B0950+08)
-1.25±0.04

-1.84±0.07

14.03.2016 Results are consistent with early obtained at 111 MHz (Smirnova, 2012)

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Individual pulses of B0809+74

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Energy distribution for B0809+74

Individual pulses' peak flux distribution

-3.84±0.50

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Strong individual pulses of B0809+74
Now it is a candidate only.

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Discovery of GPs from PSR B1133+16

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f a 1 / 1000

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Discovery of GPs from PSR B1133+16
Wavetrains

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Energy distribution for B1133+16
without a hint of a power-law distribution

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Energy distribution for B1133+16

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Conclusions
· Longtime observation program for monitoring and search GPs is conducted. · Strong individual pulses with some properties of GPs were detected from B0809+74 (more observations need). · GPs were discovered from B1133+16 and B1237+25 · There were confirmed regular GPs for 2 of 5 pulsar that was found earlier at low frequency (102-111 MHz) · We can conclude that the phenomenon of GP may be quite distributed in low radio frequencies (about 10% from our observation list) but criteria of GPs are less defined and obvious than that of 2 "classical" pulsars with GPs.
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THANK for YOUR attention

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