J/A+A/644/A73 Nulling of 20 pulsars (Wang+, 2020)
Jiamusi pulsar observations: III. Nulling of 20 pulsars.
Wang P.F., Han J.L., Han L., Cai B.Y., Wang C., Wang T., Chen X., Zhou D.J.,
Yu Y.Z., Han J., Xu J., Gao X.Y., Hong T., Hou L.G., Dong B.
<Astron. Astrophys. 644, A73 (2020)>
=2020A&A...644A..73W 2020A&A...644A..73W (SIMBAD/NED BibCode)
ADC_Keywords: Interstellar medium ; Pulsars
Keywords: pulsars: general
Abstract:
Most of pulsar nulling observations were conducted at frequencies
lower than 1400MHz. We aim to understand the nulling behaviors of
pulsars at relatively high frequency, and to check if nulling is
caused by a global change of pulsar magnetosphere.
20 bright pulsars are observed at 2250MHz with unprecedented lengths
of time by using Jiamusi 66m telescope. Nulling fractions of these
pulsars are estimated, and the null and emission states of pulses are
identified. Nulling degrees and scales of the emission-null pairs are
calculated to describe the distributions of emission and null lengths.
Three pulsars, PSRs J0248+6021, J0543+2329 and J1844+00, are found to
null for the first time. The details of null-to-emission and
emission-to-null transitions within pulse window are first observed
for PSR J1509+5531, which is a small probability event. A complete
cycle of long nulls for hours is observed for PSR J1709-1640. For
most of these pulsars, the K-S tests of nulling degrees and nulling
scales reject the hypothesis that null and emission are of random
processes at high significance levels. Emission-null sequences of
some pulsars exhibit quasi-periodic, low-frequency or featureless
modulations, which might be related to different origins. During
transitions between emission and null states, pulse intensities have
diverse tendencies for variations. Significant correlations are found
for nulling fraction, nulling cadence and nulling scales with the
energy loss rate of the pulsars. Combined with the nulling fractions
reported in literatures for 146 nulling pulsars, we found that
statistically large nulling fractions are more tightly related to
pulsar period than to characteristic age or energy loss rate.
Description:
20 pulsars (PSRs J0034-0721, J0248+6021, J0304+1932, J0332+5434,
J0528+2200, J0543+2329, J0826+2637, J0908-1739, J0922+0638,
J0953+0755, J1136+1551, J1239+2453, J1509+5531, J1709-1640, J1844+00,
J1932+1059, J2022+5154, J2048-1616, J2313+4253, and J2321+6024) were
observed at 2250MHz (S-band) with a bandwidth of about 140MHz by the
Jiamusi 66 m telescope from 2015 to 2018. The pulse sequences are
formed with single pulses or every 2, 4, 8, 16, or 32 pulses.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tablec1.dat 75 214 Nulling fractions for 214 pulsars
refs.dat 73 52 References
list.dat 125 54 List of fits files
fits/* . 54 Individual fits files
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See also:
J/A+A/618/A186 : Dynamic spectra of 10 pulsars (Wang+, 2018)
Byte-by-byte Description of file: tablec1.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- JName J Name (JHHMM+DDMM)
11 A1 --- n_JName [+] + for Intermittent pulsars
13- 21 A9 --- BName B name (BHHMM+DDf)
23- 27 F5.3 s Per Period
29- 33 F5.1 pc/cm3 DM Dispersion measure
37- 41 F5.2 % fn ? Null fraction
44- 75 A32 --- Ref Reference
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Byte-by-byte Description of file: refs.dat
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Bytes Format Units Label Explanations
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1- 6 A6 --- Ref Reference code
10- 28 A19 --- BibCode BibCode
30- 51 A22 --- Aut Author's name
53- 73 A21 --- Com Comments
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Byte-by-byte Description of file: list.dat
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Bytes Format Units Label Explanations
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1- 14 A14 --- Name PSR name
16- 17 I2 h RAh Right ascension (J2000)
19- 20 I2 min RAm Right ascension (J2000)
22- 28 F7.4 s RAs Right ascension (J2000)
29 A1 --- DE- Declination sign (J2000)
30- 31 I2 deg DEd Declination (J2000)
33- 34 I2 arcmin DEm Declination (J2000)
36- 41 F6.3 arcsec DEs Declination (J2000)
43- 46 I4 --- Nx Number lines for the spectrum
48- 66 A19 "datime" Obs.date Observation date
68- 72 I5 Kibyte size Size of FITS file
74- 85 A12 --- FileName Name of FITS file, in subdirectory fits
87-125 A39 --- Title Title of the FITS file
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Acknowledgements:
PengFei Wang, pfwang(at)nao.cas.cn
JinLin Han, hjl(at)nao.cas.cn
References:
Han et al., Paper I 2016MNRAS.456.3413H 2016MNRAS.456.3413H
Wang et al., Paper II 2018A&A...618A.186W 2018A&A...618A.186W, Cat. J/A+A/618/A186
(End) PengFei Wang [NAOC, China], Patricia Vannier [CDS] 21-Sep-2020