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. =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{deg}), using the ATNF Pulsar Catalog1 (Manchester et al., 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: -------------------------------------------------------------------------------- FileName Lrecl Records Explanations -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- Byte-by-byte Description of file: tableb1.dat -------------------------------------------------------------------------------- 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 --- l_e_DMHBA 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) -------------------------------------------------------------------------------- Note (1): References as follows: 1 = Hobbs et al. (2004, Cat. J/MNRAS/353/1311) 2 = Sayer et al. (1997ApJ...474..426S) 3 = Hassall et al. (2012A&A...543A..66H) 4 = Janssen & Stappers (2006A&A...457..611J) 5 = Lommen et al. (2000ApJ...545.1007L) 6 = Lewandowski et al. (2004ApJ...600..905L) 7 = Hamilton & Lyne (1987MNRAS.224.1073H) 8 = Camilo & Nice (1995ApJ...445..756C) Note (2): Notes as follows: b = Observations from the LOTAAS survey (Coenen et al. 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. -------------------------------------------------------------------------------- Byte-by-byte Description of file: tableb2.dat -------------------------------------------------------------------------------- Bytes Format Units Label Explanations -------------------------------------------------------------------------------- 1- 10 A10 --- PSR PSR Name 11- 12 A2 --- n_PSR IP indicates pulsars with an interpulse 16- 20 F5.2 --- d50 ?=- Spectral index {delta} 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 {delta} 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 -------------------------------------------------------------------------------- Note (1): modelled as W({nu}}{prop.to}{{nu}^{delta}^. Note (2): s: where scattering affects the measurement, no spectrum was produced. -------------------------------------------------------------------------------- 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 -------------------------------------------------------------------------------- History: From electronic version of the journal ================================================================================ (End) Patricia Vannier [CDS] 07-Apr-2016