J/A+A/445/243 Pulsar subpulse modulation properties at 21cm (Weltevrede+, 2006)
The subpulse modulation properties of pulsars at 21 cm.
Weltevrede P., Edwards R.T., Stappers B.W.
<Astron. Astrophys. 445, 243 (2006)>
=2006A&A...445..243W 2006A&A...445..243W
ADC_Keywords: Pulsars ; Radio lines
Keywords: stars: pulsars: general
Abstract:
We present the results of a systematic, unbiased search for subpulse
modulation of 187 pulsars performed with the Westerbork Synthesis
Radio Telescope (WSRT) in the Netherlands at an observing wavelength
of 21cm. Using new observations and archival WSRT data we have
increased the list of pulsars that show the drifting subpulse
phenomenon by 42, indicating that at least one in three pulsars
exhibits this phenomenon. The real fraction of pulsars that show the
drifting phenomenon is likely to be larger than 55%. The majority of
the analysed pulsars show subpulse modulation (170), of which the
majority were not previously known to show subpulse modulation and
30 show clear systematic drifting. The large number of new drifters we
have found allows us, for the first time, to do meaningful statistics
on the drifting phenomenon.
Description:
This table contains the subpulse modulation properties (at an
observing wavelength of 21cm) of the radio pulsars in the survey
conducted using the Westerbork Synthesis Radio Telescope. One can
find in this table properties like the measured modulation index and
the horizontal and vertical driftband separation.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
table2.dat 128 192 The subpulse modulation properties of the pulsars
in the survey (at an observing wavelength of 21cm)
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Byte-by-byte Description of file: table2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- Name Name of pulsar
12- 15 A4 --- Class The classification we made (1)
17- 22 F6.4 s P0 Pulse period
24- 31 E8.1 --- dP/dt Spin down parameter
33- 38 I6 --- NPulses Number of pulses in observation
40- 44 I5 --- S/R Signal to noise ratio
46- 50 F5.3 --- m ? Modulation index
52- 56 F5.3 --- e_m ? Uncertainty on the m
58- 61 F4.2 --- mthr Threshold value for detection m
63- 68 F6.1 deg P2 ? Centroid P2 value
69 A1 --- u_P2 [?] Flag for unknown value
71- 75 F5.1 deg E_P2 ? Positive uncertainty on P2
77- 81 F5.1 deg e_P2 ? Negative uncertainty on P2
83- 88 F6.3 --- P3 ? Centroid P3 value, in units of P0
90- 95 F6.3 --- e_P3 ? Uncertainy on P3, in units of P0
97-102 F6.1 deg P22 ? Centroid P2 value (2)
103 A1 --- u_P22 [?] Flag for unknown value
105-109 F5.1 deg E_P22 ? Positive uncertainty on P2 (2)
111-115 F5.1 deg e_P22 ? Negative uncertainty on P2 (2)
117-122 F6.3 --- P32 ? Centroid P3 value, in units of P0 (2)
124-128 F5.3 --- e_P32 ? Uncertainy on P3, in units of P0 (2)
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Note (1): Classification as follows:
Coh = coherent drifter
Dif = diffuse drifters with drift features which are clearly
separated from the alias borders
Dif* = diffuse drifters without drift features which are clearly
separated from the alias borders
Lon = pulsars showing longitude stationary subpulse modulation
Note (2): These values are for the second component of the pulse profile,
see the paper for details.
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Acknowledgements: Patrick Weltevrede, wltvrede(at)science.uva.nl
(End) Patricia Vannier [CDS] 05-Sep-2005