Radio Emission from RRAT J1819-14 at Low Frequencies

Radio Emission from Radio Emission from RRAT J1819-14 at RRAT J1819-14 at Low FrequenciesLow Frequencies

Teplykh D., Malofeev V., Logvinenko S.

9-th GAMOW SUMMER SCHOOL

Neutron starsNeutron stars

Rns ~ 10 kmMns ~ M

Bns ~ 1012 — 1013 Gp ~ ms - s


Anomalous pulsarsAnomalous pulsarsGemingaAnomalous X-ray pulsars (AXPs)Soft gamma-ray repeaters(SGRs)X-ray dim isolated neutron stars (XDINSs)Compact X-ray objects in remnant of

supernova (CCO)Transient pulsars: - Rotating radio transients (RRATs) - switch off (B1931+24)


RRATsRRATs

• These sources are characterized by the emission of bursts with duration 2–30 ms.

• The maximum burst flux density is 0.1– 4 Jy.• The mean interval between bursts is 4 min–3

hrs• The 10 of 11 sources have periods in the range

0.4–7 s. And the period derivative ˙P was measured for 3 pulsars.

• The inferred magnetic fields are in the 1012 – 1014 G, and ages of these objects are 0.1–3 Myrs.


RRATsRRATs Name P, s w50, ms dP/dt, 10-15 DM D,kpc S1400, mJy Np /Tobs

J0848-43 5.97748(2) 30 293(19) 5.5 100 27/19

J1317-5759 2.6421979742(3) 10 12.6(7) 145.4(3) 3.2 1100 108/24

J1443-60 4.758565(5) 20 369(8) 5.5 280 32/41

J1754-30 0.422617(4) 16 98(6) 2.2 160 18/30

J1819-1458 4.263159894(6) 3 576(1) 196(3) 3.6 3600 229/13

J1826-14 0.7706187(3) 2 159(1) 3.3 600 18/17

J1839-01 0.93190(1) 15 307(10) 6.5 100 8/13

J1846-02 4.476739(3) 16 239(10) 5.2 250 11/10

J1848-12 6.7953(5) 2 88(2) 2.4 450 10/8

J1911+00 5 100(3) 3.3 250 4/13

J1913+1333 0.9233885242(1) 2 7.87(2) 175.8(3) 5.7 650 66/14

B1931+24 0.813690303 0.6 7.15-10.79

B0656+14 0.384885 2 55.01


JJ1819-141819-145858

M.A.McLaughlin et al. Nature, 439, 817-820 (2006)

• - pulsars - magnetars - XDINS - RRATs

Burst observational signatures

The rotational properties of neutron stars


ObservationsObservations

LPA: 111.5 ± 1.5 МHz, 3.3 m / cos , Aef 20 000 m2

Receivers: 96 20 kHz, 460 5 kHz t = 28.06 ms

J18J1819-1419-14 46 periods of pulsars were recorded during a single

observation session. On the whole 33 observation sessions have been

made.

9-th GAMOW SUMMER SCHOOLLarge Phased ArrayLarge Phased Array


JJ11331133+16+16010209_1133+16_00 SNR=28.0

Номер точки в окне480460440420400380360340320300280260240220200180160140120100806040200

Мощ

ност

ь

264

263

262

261

260

259

• S = 1000 mJy

• Р = 1,1 s• DM = 4,8• Δt = 2,56

ms

• 482 periods470 chan = 111.88 MHz

10 chan = 109.59MHz

at 111 at 111 MHzMHz


BB2310+42310+422101108_2310+42_00 SNR=11.4


Мощ

ност

ь

523

522

521

• S = 110 mJy• Р = 0,35 s• DM = 17,3• Δt = 5,12

ms

• 375 groups

101108_2310+42_00 SNR=11.4


Мощ

ност

ь

523

522

521

Pulse phase (ms)

Rel

ativ

e fl

ux d

ensi

ty

470 chan = 111.88 MHz

10 chan = 109.59MHz



JJ1819-141819-14

• Sum of 4 days (January 2009)

• 49 pulses

Суммарный профиль

4,0003,5003,0002,5002,0001,5001,0005000

1.006

1.005

1.005

1.004

1.004

1.003

1.003

1.002

1.002

1.001

1.001

1

1

0.999



1819-1819-1414Суммарный профиль

4,0003,5003,0002,5002,0001,5001,0005000

1.006

1.005

1.005

1.004

1.004

1.003

1.003

1.002

1.002

1.001

1.001

1

1

0.999

• Sum of 4 days (January 2009)

• 49 pulses

• With compensation for DM = 196



1819-1819-1414Суммарный профиль

4,0003,5003,0002,5002,0001,5001,0005000

1.004

1.004

1.004

1.003

1.003

1.002

1.002

1.001

1.001

1

1

0.999

• Sum of 7 days• (January 2009)• 93 pulses



1819-1819-1414at 111 at 111

MHzMHz• Sum of 7 days(February - March 2009)

• 109 pulses


4.0003.5003.0002.5002.0001.5001.0005000

1.006

1.0061.005

1.0051.004

1.0041.003

1.0031.002

1.0021.001

1.0011

10.999


1819-1819-1414at 111 at 111

MHzMHz• Sum of 7 days(February - March 2009)

• 109 pulses


4.0003.5003.0002.5002.0001.5001.0005000

1.006

1.0061.005

1.0051.004

1.0041.003

1.0031.002

1.0021.001

1.0011

10.999

With compensation for DM = 196


Parameters of J1819-14 at 111 Parameters of J1819-14 at 111 MHzMHz

Sp(111) 17 Jy

w50 70 ms

Sp(1400) 0,4 Jy

1,5 (111-1400 MHz)

Ratio of the total number of bursts detected to the total observation time:

1400 MHz – 2%

111 MHz ~ 5%


ConclusionsConclusions

• There is radio emission from RRAT J1819-14 at 111MHz.

• The ratio of the total number of bursts detected to the total observation time is close to the ratio at 1400 MHz.

• Spectral index ~ 1.5. It is close to the mean spectral index of normal

pulsars.

Radio Emission from RRAT J1819-14 at Low Frequencies

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