Cairo 2009

Detection radio emission Detection radio emission from AXP 4U 0142+61from AXP 4U 0142+61

Malofeev V.M., Teplykh D.A.,

Rodin A.E., Logvinenko S.V.

Pushchino Radio Astronomy Observatory of Lebedev Physical Institute, Russia

Cairo 2009

Anomalous pulsarsAnomalous pulsars

GemingaAnomalous 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 (RRATS + switch off)…

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№ Source Р, с Р' lg Lx (erg/s) lg Ė (erg/s)

AXP

1 1E1048.1-5937 6.45 12.2 10 -11 34.30 33.51 2 1E2259+586 6.98 7.3 10 -13 34.90 31.93 3 4U0142+61 8.69 3 10 -12 34.90 32.26 4 RXSJ170849-4009 11.00 3 10 -11 35.95 32.95 5 1E1841-045 11.77 4.7 10 -11 35.48 33.06 6 AXJ1845.0-0258 6.97 34.70 7 XTEJ1810-197 5.54 1 10 -11 36 33.6

8 CXOU J0110043.1-721134 8.0 9 1E 1547.0-5408 2.07 2.3 10 -11 35.00 SGR

1 SGR0526-66 8.1 8.3 10 -13 36 – 37

2 SGR1806-20 7.48 1.1 10 -10 35.30 33.79

3 SGR1900+14 5.16 1.23 10-10 34.48 34.50

4 SGR1627-41 6.4? 35

5 SGR1801-23

XDINS 1 J1856.5-3754 (RX 1856) 7.055 2 J0720.4-3125 (RX 0720) 8.39 31.48 3 1RXSJ130848.6+212708 10.31 (0.7 - 2.0) 10 -11 32.61 33.30 – 33.76 4 J1605.3+3249 (RBS 1556) 6.88

5 J0806.4-4123 (RX 0806) 11.37

6 J0420-5022 (RX 0420) 3.45 7 1 RXS J214303.7+065419 9.44 (28 – 31) (31.0)

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Main problemMain problem

None of the AXPs and SGRs show the evidence of a binary companion and the main problem is the source of their energies, because their X-ray luminosities are much higher than can be provided by the rotational kinetic-energy losses.

The most popular magnetar model of Thompson & Duncan (1996) proposes the enormous surface magnetic fields 1014 - 1015 G and the absence of radio emission from these objects (Baring & Harding 1998).

Many attempts have been made to detect radio emission, for example Gaensler et al. (2001).

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LPA: 111.5 ± 1.5 МHz,

3.3 m / cos , Aef 20 000 m2

Cross Type Radio Telescope: 87 МHz, 62 МHz, 42 MHz

15 m / cos , Aef 5 – 8 103 m2

Receivers: 64 20 kHz, t = 25.6 ms, 51.1 ms, 61.9 ms

Digital receivers at 111 and 42 MHz: 511 5 kHz

4U 0142+61Recording of 46 periods or 23 double periods

ObservationsObservations

Cairo 2009Large Phased ArrayLarge Phased Array

Cairo 2009Cross Type Radio TelescopeCross Type Radio Telescope

Cairo 2009

(A) 4U 0142+61

(B) 1RXS 1708-4009

(C) 1E 2259.1+586

An optical counterpart for 4U 0142+61

(R = 24.98)

F. Hulleman et al., Nature 408, 689, 2000.

Optical pulsations (27%)

B.Kern, C.Martin, Nature 417, 527, 2002.

Average pulse profiles of the AXPs:

Cairo 2009

• The observations were started in 1999

• Pulse profile obtained when the observing window equals twice the apparent period (p = 6.978 s). The summing of 12 days was made with the superposition of visible pulses at the phase ~ 0.58 (red arrow). Second pulse shows up at the phase 1.58 (blue arrow). The mean profile for one period obtained by the folding of data (lower).

111.23 MHz111.23 MHzMalofeev et al 2001,2004,2005

Sum of 12 days

312 periods

624 periods

S/n = 10

1E2259+5861E2259+586

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XTE J1810-197XTE J1810-197

F.Camilo et al., Nature, 442, 892, 2006.

Cairo 2009

1E 1547.0 - 54081E 1547.0 - 5408

p = 2.069 c

p’ = (2.318±0.005)·10-11

Camilo et al., Astrophys.J, 666, 2007

Cairo 2009

4U 0142+614U 0142+61

• Pulse profile obtained when the observing window equals twice the apparent period (p = 8.69 s). The summing of 2 days was made with the superposition of visible pulses at the phase ~ 0.4 (red arrow). Second pulse shows up at the phase 1.4. The mean profile for one period obtained by the folding of data (lower).

Cairo 2009

111.23 MHz111.23 MHz4U 0142+614U 0142+61

Pulse profile obtained when the observing window equals twice the apparent period (p = 8.69 s). The summing of 24 days was made with the superposition of visible pulses at the phase ~ 0.17. Second pulse shows up at the phase 1.17. The mean profile for one period obtained by the folding of data (lower).

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4U 0142+614U 0142+61111.23 MHz111.23 MHz

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4U 0142+614U 0142+6140.96 MHz40.96 MHz

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2310+422310+42

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

• 375 groups

470 chan = 111.88 MHz

10 chan = 109.59MHz

101108_2310+42_00 SNR=11.4

Номер точки в окне12512011511010510095908580757065605550454035302520151050

Мощ

ност

ь

523

522

521

Pulse phase (ms)

Rel

ativ

e fl

ux d

ensi

ty

Cairo 2009

4U 0142+614U 0142+61

Sum of 9 days

(february – march 2006)

Sum of 67 groups

S/n = 9.4

109.59 – 111.88 MHz

Sample = 50,99 ms

111 MHz111 MHzСуммарный профиль

16.00014.00012.00010.0008.0006.0004.0002.0000

1.003

1.003

1.002

1.002

1.001

1.001

1

1

0.999

Pulse phase (ms)

Rel

ativ

e fl

ux d

ensi

ty

Cairo 2009

4U 0142+614U 0142+61

Sum of 3 days (16, 18, 21.09.08)

Sum of 16 groups

S/n = 6.7

41.86 - 42.66 MHz

Sample = 50,99 ms

42 MHz42 MHz

Суммарный профиль

16,00014,00012,00010,0008,0006,0004,0002,0000

1.007

1.006

1.005

1.004

1.003

1.002

1.001

1

0.999

0.998

0.997

Pulse phase (ms)

Rel

ativ

e fl

ux d

ensi

ty

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4U 0142+614U 0142+61

Arrival time residuals for 4U 0142+61

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Pulse frequency history for 4U 0142+61, Kaspi et al. 2002

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Parameters of AXPs at 111 MHzParameters of AXPs at 111 MHz

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ConclusionsConclusions There is radio emission from AXP, SGR and XDINS at low radio

frequencies. We have obtained independent estimates of the distances to pulsars,

which are within the intervals of distances determined using other methods.

The main difference between the radio from the X-ray pulsed emission is that the integrated radio pulses of all objects are much narrower, including AXP 4U0142+61.

The discovery of radio emission from AXP(Malofeev et al. 2001, 2005, 2007), SGR (Shitov et al. 2000) together with the detection of transient pulsed radio emission from AXP XTE J1810-197, 1E 1547.0 - 5408 (Camilo et al. 2006, 2007) and from radio pulsar with p = 6.7 s and p• = 1.3 ·10-12 s/s (McLaughlin et al. 2003) gives a reason to revise either the radio emission mechanisms in the “magnetar” model or the “magnetar” model itself.