YERAC-2013
Montoring of Giant Pulses with the
LPA LPI at the frequensy of 111
MHz
Kazantsev A.N.(1,2) & Potapov V.A.(1)
(1) PRAO ASC LPI, Pushchino
(2) Pushchino State Nat.Sci.Inst., Pushchino
Bielefeld, 2013
Giant Radio Pulses (GRPs) of pulsars.
 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).
 High level of linear and circular polarization of pulse. E.g. ~60%
GRP of PSR B1937+21 are 100% circular polarized.
 GRPs have a power law distribution both for peak flux and
pulse’s energy. Normal pulses have a Gaussian distribution on a
logarithmic scale.
 GRPs have duration of 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).
 The highest brightness temperature:
B0531+21 -TB≥5×1037K;
B1937+21 - TB≥5×1039K
«Classical» GRPs
Pulsar in Crab nebulae (B0531+21) has most famous and the first discovered
GRPs.
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)
GRPs energy distribution, B0531+21
Popov et al., 2009
Individual pulses energy distribution, B1937+21
Cognard et al. 1996
Histograms of relative peak flux (vs. flux of
averaged profile), classification.
2695 MHz
(Hesse & Wielebinski) , 1974
Pulsars with GRPs
Name
P, s
P1, s/s
Frequenc
y, MHz
DM, sm-3
pc
B on
LC, Gs
First
reference
J0034-0721
0.9429
4.08e-16
40
11.380
7.02e+00
2004
J0218+4232
0.0023
7.73e-20
610
61.252
3.21e+05
2004
J0534+2200
0.0331
4.23e-13
40-8300
56.791
9.80e+05
1968
J0529-6652*
1.0249
7.73e-11
610
103.20
3.97e+01
2011
J0540-6919*
0.0505
4.79e-13
1390
146.500
3.62e+05
2006
J0659+1414
0.3849
5.50e-14
111
13.977
7.66e+02
2003
J0953+0755
0.2530
2.30e-16
111
2.958
1.41e+02
2003
J1115+5030
1.6564
2.49e-15
111
9.195
4.24e+00
2003
B1237+25**
1.38245
9.60e-16
111
9.242
4.14e+00
2012
J1752+2359
0.4091
0.64e-15
111
36.000
7.11e+01
2005
J1824-2452
0.0030
1.62e-18
1510
120.500
7.41e+05
2001
J1823-3021
0.0054
3.38e-18
685
86.834
2.52e+05
2005
J1939+2134
0.0016
1.05e-19
111-5500
71.0398
1.02e+06
1984
J1959+2048
0.0016
1.69e-20
610
29.1168
3.76e+05
2004
* - pulsar in LMC, ** - discovered in our observations
Open questions.
What
are the differences in properties/statistics for
pulsars from 3 sets mentioned above?
How many pulsars with low BLC have GRPs?
How strict and valuable statistical criterion is?
(Power law/Gaussian distribution of pick flux for
GP/normal pulses)?
How stable are GRPs generated and how their
properties change at long time intervals?
Have to collect long data set to test different
theories of GRPs generation. The same or two
different models for normal and GRPs generation?
Goals and program of research.
 To
make regular long time observations of pulsar.
Observations of strong second and millisecond pulsars
at 111 MHz frequency.
 Search for pulses with peak flux in more than 30
average pulse.
 Building distributions on peak flux/energy for these
pulses.
 Testing of statistical criterion by comparison
distributions for pulsars with GRPs and regular pulsars,
LPA of LPI radio telescope
 Scanning
meridional phased array, One linear polarization.
 Frequency: 111 MHz, Bandwidth: 2.3 MHz (460 x 5 kHz digital receiver
with post-detector DM removal);
 Duration of one scan: 3 to 7 min. (e.g. B1237+21 - 3.53 min = 153 pulses);
Objects observed
36 pulsars:
J0034-0721
J0922+0638
J1752+2359
J2018+2839
J0218+4232
J0953+0755
J1830-1059
J2022+2854
J0304+1932
J1115+5030
J1841+0912
J2030+3641
J0323+3944
J1239+2453
J1840+5640
J2032+4127
J0454+5543
J1509+5531
J1857+0943
J2113+2754
J0659+1414
J1537+1155
J1921+1419
J2113+4644
B0711+09
J1543+0929
J1932+1059
J2157+4017
J0814+7429
J1652+2651
J1948+3540
J2313+4253
J0826+2637
J1740+1311
J1957+2831
J2317+2149
Negative results
 No
regular GRPs for: J0034-0721 (B0031-07),
J0659+1414 (B0656+14) & J1752+2359 (40, DCR-100
& 102-111 MHz, LPA LPI)
 J0218+4232 & J1959+2048 (B1957+20) (610 MHz,
GMRT).
Strongest detected pulse of B0031-07
Positive results
First discovered GRPs of B1237+25 (J1239+2453)
Regular GRPs confirmed for B1112+50 &
B0950+08
Strong individual pulses of B0809+74 were found
(S > 20 ave. pulse) observed earlier in decameter
wavelengths (Ulyanov et al. 2006)
GRPs of B1237+25 (14.05.12 & 04.05.12)
Individual pulses histograms.
111 MHz
2695 MHz
Differs for histogram at 2695 MHz (no sub=peaks). Much stronger in maximum
K.H. Hesse & R. Wielebinski, 1974
GRP peak flux distribution (B1237+25).
-1.26±0.05
-3.36±0.34
Strongest GRP: Smax = 900±200 Jy.
GRPs B1112+50 monitoring
GRPs of B1112+50 distributions
Ershov, Kuzmin, 2003
Kazantsev, Potapov, 2013
GRPs B0950+08 monitoring
111 MHz
2695 MHz
GRP phase distribution (B0950+08), mode
changes.
GRP peak flux distribution (B0950+08).
-1.25±0.04
-1.84±0.07
Results are consistent with early obtained (Smirnova, 2012)
Search for GRPs of PSR B0809+74
Individual pulses’ peak flux distribution.
-3.84±0.50
Individual pulses of B1508+55
111 MHz
2695 MHz
Individual pulses peak flux distribution (B1508+55)
-1.01±0.10
-4.39±0.48
Statistics of monitoring 10.2011 – 04.2013
Pulsar
name
Flux in averaged profiles
>5
>10
>15
>20
>30
>50
>100
B0809+7
4
9799
2355
503
125
14
0
0
B0950+0
8
5764
2659
1372
727
253
51
4
B1112+5
0
2931
1602
851
456
153
33
2
B1237+2
5
1742
518
208
81
26
6
0
B1508+5
5
774
34
2
0
0
0
0
Summary
 For
the first time discovered GRPs of PSR B1237+25, and,
probably of PSR B0809+74 (early detected as strong wide
pulses at 23.7MHz).
 It can be separated subset of pulsars with GRPs, having BLC ~ 1100 Gs, quite wide profiles and tenths or hundreds times
stronger than averaged pulses. Such GRPs may be observed at
meter and decameter wavelengths (referred as Anomalous
Intensive Pulses - AIP).
 This subset of pulsars with GRPs maybe wide distributed
between second period pulsars. We’d found 3.3 (6.6 ?) % of
such pulsars in our random sampling of objects.
 Statistical criterion is not quite valuable because of regular
pulsars (I/II type in Hesse-Wielebinski classification) may have
the similar power law distribution of strong pulses.
 Some of such pulsars have “nullings” in GRP generation (3
from 7 pulsars in our sample).
Vielen Dank für Ihre
Aufmerksamkeit
Спасибо за внимание
Thank you for your attention