J/A+A/586/A92 Pulse profiles of 100 radio pulsars (Pilia+, 2016)
Wide-band, low-frequency pulse profiles of 100 radio pulsars with LOFAR.
Pilia M., Hessels J.W.T., Stappers B.W., Kondratiev V.I., Kramer M.,
van Leeuwen J., Weltevrede P., Lyne A.G., Zagkouris K., Hassall T.E.,
Bilous A.V., Breton R.P., Falcke H., Griessmeier J.-M., Keane E.,
Karastergiou A., Kuniyoshi M., Noutsos A., Oslowski S., Serylak M.,
Sobey C., Ter Veen S., Alexov A., Anderson J., Asgekar A., Avruch I.M.,
Bell M.E., Bentum M.J., Bernardi G., Birzan L., Bonafede A., Breitling F.,
Broderick J.W., Brueggen M., Ciardi B., Corbel S., De Geus E., De Jong A.,
Deller A., Duscha S., Eisloeffel J., Fallows R.A., Fender R., Ferrari C.,
Frieswijk W., Garrett M.A., Gunst A.W., Hamaker J.P., Heald G.,
Horneffer A., Jonker P., Juette E., Kuper G., Maat P., Mann G., Markoff S.,
McFadden R., McKay-Bukowski D., Miller-Jones J.C.A., Nelles A., Paas H.,
Pandey-Pommier M., Pietka M., Pizzo R., Polatidis A.G., Reich W.,
Roettgering H., Rowlinson A., Schwarz D., Smirnov O., Steinmetz M.,
Stewart A., Swinbank J.D., Tagger M., Tang Y., Tasse C., Thoudam S.,
Toribio M.C., van der Horst A.J., Vermeulen R., Vocks C., van Weeren R.J.,
Wijers R.A.M.J., Wijnands R., Wijnholds S.J., Wucknitz O., Zarka P.
<Astron. Astrophys., 586, A92-92 (2016)>
=2016A&A...586A..92P 2016A&A...586A..92P (SIMBAD/NED BibCode)
ADC_Keywords: Pulsars ; Radio sources
Keywords: stars: neutron - pulsars: general
Abstract:
LOFAR offers the unique capability of observing pulsars across the
10-240MHz frequency range with a fractional bandwidth of roughly 50%.
This spectral range is well suited for studying the frequency
evolution of pulse profile morphology caused by both intrinsic and
extrinsic effects such as changing emission altitude in the pulsar
magnetosphere or scatter broadening by the interstellar medium,
respectively. The magnitude of most of these effects increases rapidly
towards low frequencies. LOFAR can thus address a number of open
questions about the nature of radio pulsar emission and its
propagation through the interstellar medium. We present the average
pulse profiles of 100 pulsars observed in the two LOFAR frequency
bands: high band (120-167MHz, 100 profiles) and low band (15-62MHz, 26
profiles). We compare them with Westerbork Synthesis Radio Telescope
(WSRT) and Lovell Telescope observations at higher frequencies (350
and 1400MHz) to study the profile evolution. The profiles were aligned
in absolute phase by folding with a new set of timing solutions from
the Lovell Telescope, which we present along with precise dispersion
measures obtained with LOFAR. We find that the profile evolution with
decreasing radio frequency does not follow a specific trend; depending
on the geometry of the pulsar, new components can enter into or be
hidden from view. Nonetheless, in general our observations confirm the
widening of pulsar profiles at low frequencies, as expected from
radius-to-frequency mapping or birefringence theories.
Description:
The observed sample of pulsars was loosely based on a selection of the
brightest objects in the LOFAR-visible sky (declination >-30°),
using the ATNF Pulsar Catalog1 (Manchester et al.,
2005AJ....129.1993M 2005AJ....129.1993M) for guidance.
We observed 100 pulsars using the high-band antennas (HBAs) in the six
central "Superterp" stations (CS002-CS007) of the LOFAR core.
File Summary:
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FileName Lrecl Records Explanations
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ReadMe 80 . This file
tableb1.dat 123 100 List of the 100 pulsars and their rotational
and derived parameters
tableb2.dat 181 100 Width of the full profile and duty cycle
tableb3.dat 127 29 Peak ratios
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Byte-by-byte Description of file: tableb1.dat
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Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1- 10 A10 --- PSR PSR Name (BHHMM+DD or JHHMM+DDMM)
12- 16 F5.3 s P Spin period
18- 26 E9.4 s/s dP/dt Period derivative
28- 32 I5 d Epoch Reference epoch of the rotational ephemeris
that was used to fold the data (MJD)
34- 38 I5 d EpochL ? Lofar LBA observation epoch (MJD)
40- 44 I5 d EpochH Lofar HBA observation epoch (MJD)
46- 53 F8.4 pc/cm3 DMeph Dispersion measure used to dedisperse the
observations at higher frequencies
55- 60 F6.4 pc/cm3 e_DMeph rms uncertainty on DMeph
63 I1 --- r_DMeph Reference for DMeph (1)
66- 73 F8.4 pc/cm3 DMHBA Best dispersion measure obtained from the
fit of the HBA LOFAR observations
76 A1 --- leDMHBA Limit flag on DMHBA
77- 82 F6.4 pc/cm3 e_DMHBA rms uncertainty on DMHBA
85- 88 F4.2 [yr] logtau Pulsar spin-down age
90- 94 F5.2 [gauss] logB Magnetic field strength
96-100 F5.2 [10-7W] logdE/dt Spin-down luminosity as derived from the
rotational parameters
103-109 A7 --- Obs1 Note on observation
111 A1 --- n_Obs1 [bcd] Note for Obs1 (2)
112 A1 --- --- [,]
114-120 A7 --- Obs2 Note on observation
123 A1 --- n_Obs2 [bcd] Note for Obs2 (2)
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Note (1): References as follows:
1 = Hobbs et al. (2004, Cat. J/MNRAS/353/1311)
2 = Sayer et al. (1997ApJ...474..426S 1997ApJ...474..426S)
3 = Hassall et al. (2012A&A...543A..66H 2012A&A...543A..66H)
4 = Janssen & Stappers (2006A&A...457..611J 2006A&A...457..611J)
5 = Lommen et al. (2000ApJ...545.1007L 2000ApJ...545.1007L)
6 = Lewandowski et al. (2004ApJ...600..905L 2004ApJ...600..905L)
7 = Hamilton & Lyne (1987MNRAS.224.1073H 1987MNRAS.224.1073H)
8 = Camilo & Nice (1995ApJ...445..756C 1995ApJ...445..756C)
Note (2): Notes as follows:
b = Observations from the LOTAAS survey (Coenen et al. 2014A&A...570A..60C 2014A&A...570A..60C)
c = Year of the P- and/or L-band data from WSRT observations. L-band data
were obtained from Lovell observations in all but the three cases where
the year of the WSRT observations is indicated. All the L-band
observations using the Lovell telescope were performed between October
2011 and November 2013.
d = Where P-band data were available from Weltevrede et al. (2005,
Cat. J/A+A/445/243), but no absolute reference was available to align
the data with LOFAR data, reference is made to their paper as WES and
the corresponding profile in Fig. B.1 was aligned by eye. For
completeness, where the pulsar was not in WES, then EPN indicates that
the profile in P-band was obtained from the EPN pulsar database and was
also only aligned by eye. In this latter case, the observations are not
later than 2002.
In the cases where nothing is specified, for the P-band the profile is
either missing in all the databases used here or the Lovell data were used
and the profile aligned with the standard procedure as described in the
text.
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Byte-by-byte Description of file: tableb2.dat
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Bytes Format Units Label Explanations
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1- 10 A10 --- PSR PSR Name
11- 12 A2 --- n_PSR IP indicates pulsars with an interpulse
16- 20 F5.2 --- d50 ?=- Spectral index δ of the evolution
of W50 with observing frequency (1)
22- 24 F3.2 --- e_d50 ?=- rms uncertainty on d50
27- 31 F5.2 --- d10 ?=- Spectral index δ of the evolution
of W10 with observing frequency (1)
33- 35 F3.2 --- e_d10 ?=- rms uncertainty on d10
40- 42 A3 --- Band1 [LBA]
45- 48 F4.1 deg W50LBA ?=- LBA-band full width at half maximum, W50
50- 52 F3.1 deg e_W50LBA ? rms uncertainty on W50LBA
54- 57 F4.1 deg W10LBA ?=- LBA-band width of the full profile, W10
59- 61 F3.1 deg e_W10LBA ? rms uncertainty on W10LBA
63- 67 F5.2 % W10/PLBA ? LBA-band duty cycle of the pulse, W10/P,
indicated as percent age of the total profile
69- 72 F4.2 % e_W10/PLBA ? rms uncertainty on W10/PLBA
74 A1 --- SatLBA [s] s for saturated (2)
76- 78 A3 --- Band2 [HBA]
80- 83 F4.1 deg W50HBA ?=- HBA-band full width at half maximum, W50
85- 87 F3.1 deg e_W50HBA ? rms uncertainty on W50HBA
89- 92 F4.1 deg W10HBA ?=- HBA-band width of the full profile, W10
94- 96 F3.1 deg e_W10HBA ? rms uncertainty on W10HBA
98-102 F5.2 % W10/PHBA ? HBA-band duty cycle of the pulse, W10/P,
indicated as percent age of the total profile
104-107 F4.2 % e_W10/PHBA ? rms uncertainty on W10/PHBA
109 A1 --- SatHBA [s] s for saturated (2)
111 A1 --- Band3 [P]
113-117 F5.2 deg W50P ?=- P-band full width at half maximum, W50
119-122 F4.2 deg e_W50P ? rms uncertainty on W50P
124-129 F6.2 deg W10P ?=- P-band width of the full profile, W10
131-135 F5.2 deg e_W10P ? rms uncertainty on W10P
137-141 F5.2 % W10/PP ? P-band duty cycle of the pulse, W10/P,
indicated as percent age of the total profile
143-146 F4.2 % e_W10/PP ? rms uncertainty on W10/PP
149 A1 --- Band4 [L]
151-155 F5.1 deg W50L ?=- L-band full width at half maximum, W50
157-159 F3.1 deg e_W50L ? rms uncertainty on W50L
161-165 F5.1 deg W10L ?=- L-band width of the full profile, W10
167-169 F3.1 deg e_W10L ? rms uncertainty on W10L
172-176 F5.2 % W10/PL ? L-band duty cycle of the pulse, W10/P,
indicated as percent age of the total profile
178-181 F4.2 % e_W10/PL ? rms uncertainty on W10/PL
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Note (1): modelled as W(ν∝{νδ.
Note (2): s: where scattering affects the measurement, no spectrum was produced.
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Byte-by-byte Description of file: tableb3.dat
--------------------------------------------------------------------------------
Bytes Format Units Label Explanations
--------------------------------------------------------------------------------
1 A1 --- Flag [pn] p for previously studied cases and
and n for new
3- 12 A10 --- PSR PSR Name
13- 14 A2 --- n_PSR IP indicates pulsars with an interpulse
17- 19 A3 --- Band1 [LBA]
21- 24 F4.2 --- P1LBA ? LBA-band amplitude of the most prominent
peak normalised to the amplitude of the main
peak of the profile
26- 29 F4.2 --- P2LBA ? LBA-band amplitude of the second most
prominent peak normalised to the amplitude
of the main peak of the profile
31- 34 F4.2 --- phi1LBA ? LBA-band spin phase of the most prominent
peak
36- 39 F4.2 --- phi2LBA ? LBA-band spin phase of the second most
prominent peak
41- 44 F4.2 --- P2/P1LBA ? LBA-band P2/P1 ratio
46- 48 A3 --- Band2 [HBA]
50- 53 F4.2 --- P1HBA ? HBA-band amplitude of the most prominent
peak normalised to the amplitude of the main
peak of the profile
55- 58 F4.2 --- P2HBA ? HBA-band amplitude of the second most
prominent peak normalised to the amplitude
of the main peak of the profile
60- 63 F4.2 --- phi1HBA ? HBA-band spin phase of the most prominent
peak
65- 68 F4.2 --- phi2HBA ? HBA-band spin phase of the second most
prominent peak
70- 73 F4.2 --- P2/P1HBA ? HBA-band P2/P1 ratio
75 A1 --- Band3 [P]
77- 80 F4.2 --- P1P ? P-band amplitude of the most prominent peak
normalised to the amplitude of the main peak
of the profile
82- 85 F4.2 --- P2P ? P-band amplitude of the second most
prominent peak normalised to the amplitude
of the main peak of the profile
87- 90 F4.2 --- phi1P ? P-band spin phase of the most prominent peak
92- 95 F4.2 --- phi2P ? P-band spin phase of the second most
prominent peak
97-100 F4.2 --- P2/P1P ? P-band P2/P1 ratio
102 A1 --- Band4 [L]
104-107 F4.2 --- P1L ? L-band amplitude of the most prominent peak
normalised to the amplitude of the main peak
of the profile
109-112 F4.2 --- P2L ? L-band amplitude of the second most
prominent peak normalised to the amplitude
of the main peak of the profile
114-117 F4.2 --- phi1L ? L-band spin phase of the most prominent peak
119-122 F4.2 --- phi2L ? L-band spin phase of the second most
prominent peak
124-127 F4.2 --- P2/P1L ? L-band P2/P1 ratio
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History:
From electronic version of the journal
(End) Patricia Vannier [CDS] 07-Apr-2016