Southern Pulsars Research Articles

A Search for Optical Pulsations from Two Young Southern Pulsars

We report on high-speed optical photometry of the radio positions of two young rotation-powered pulsars. No pulsations were detected from the optical counterpart proposed by Caraveo et al. for PSR B1509-58, with a 2 σ upper limit on the pulsed fraction of less than 12%, significantly lower than that measured in the five known optical pulsars. Given its low pulsed fraction, high optical luminosity, and significant (8%) chance coincidence probability, we suggest that this candidate is not associated with the pulsar. We also find that the still unidentified optical counterpart of PSR B1706-44 has R18 and lies within 3'' of an R=16.6 star.

Polarization observations of 66 southern pulsars

Mean pulse profiles and polarization parameters at 435, 660 or 1500 MHz obtained using the ATNF Parkes radio telescope are presented for 66 southern pulsars. About half of these pulsars were discovered in the Parkes southern pulsar survey and most have no previously published polarization parameters. Where possible, beam impact parameters and inclination angles are computed assuming a circular beam geometry and the rotating-vector model. Implications of the results for models of the pulse emission mechanism are briefly discussed.

Long-term timing observations of four southern pulsars

Pulse arrival-time measurements made during the period 1987-1994 at the Mt Pleasant Observatory have revealed the first observed glitch in PSR B1727-47 and a continuation of the known high glitch rate in PSR B1737-30. The observations also show an unusual sequence of alternating microjumps in the rotation rate of PSR B1240-64 and the possibility of free precession in PSR B0959-54. The observations and results are discussed in terms of current neutron star theories. © 1997 RAS.

Power spectrum analysis of the timing noise in 18 southern pulsars

Power spectra of the timing noise observed in 18 southern pulsars have been derived using a novel technique, based on the CLEAN algorithm. Most of the spectra are well described by a single- or double-component power-law model. Some of these spectra can be interpreted in the context of one or more of the current timing noise models. The results combined with those obtained from the time-domain analyses of the timing activity in these pulsars are used to assess the viability of the various theoretical models of pulsar timing noise.

Polarimetric observations of southern pulsars at 800 and 950 MHz

Polarimetric data are presented for a total of 82 (mostly southern) pulsars at observing frequencies of 800 MHz (18 pulsars) and 950 MHz (82 pulsars). 32 of the sources were observed using a high-speed integrator with milliperiod resolution. For many of the pulsars observed, there is no published polarimetry and, for most, these observations constitute the only data between 630 and 1612 MHz. Faraday rotation measurements for 24 pulsars are also presented. Most of the pulsars examined show properties that are readily explicable in terms of core and conal components. Notable results include integrated profile mode-changing identified for the first time in PSR B1358 - 63, confirmation of high inclinations between magnetic and rotation axes in the interpulsars PSR B1055 - 52 and PSR B1702 - 19, and significant rotation measure changes in PSR B1556 - 44 and PSR B1727 - 47. © 1997 RAS.

Kinematic distances for southern pulsars: Gum & Carina

We have observed 21-cm absorption and emission spectra in the direction of about 20 southern pulsars with the Parkes telescope to derive their kinematic distances and to study the interstellar medium. In each case we thoroughly investigated the environment of each pulsar as well as sources along the line of sight which may contribute to the pulsars’ dispersion measure (DM).Some of the results, which are published in Koribalski et al. (1995) and Johnston et al. (1996), are included in the compilation of Hi absorption measurements by Joel Weisberg in this volume. In the following we present a detailed discussion on pulsars toward 1) the Gum Nebula and 2) the Carina Arm.

The timing noise of 45 southern pulsars

The timing noise of 45 southern pulsars

Polarization and Faraday rotation measurements of southern pulsars

Polarization and Faraday rotation measurements of southern pulsars

H I line measurements of eight southern pulsars

H I line measurements of eight southern pulsars

Timing observations of southern pulsars - 1987 to 1991

Pulse arrival time measurements made over a 4-yr period have been used to determine timing parameters for 45 southern pulsars. Improved periods, period derivatives, positions and dispersion measures are tabulated, and a preliminary analysis of timing irregularities is described

Mean pulse polarization of southern pulsars at 1560 MHz

Mean pulse total intensity and polarization data at 1560 MHz are presented for 45 southern pulsars. The observations were made during 1988 at Parkes using a filter-bank polarimeter system. The results are discussed in terms of the rotating vector model for pulse polarization. Notable results include a highly polarized interpulse pulsar and several pulsars with very wide mean pulse profiles

Polarization of Southern Pulsars

Polarization of Southern Pulsars

Mean Pulse Polarizations of 8 Southern Pulsars at 1560 MHz

AbstractWe present the results of mean pulse polarization observations at 1560 MHz of 8 pulsars with high southern latitude, large values of dispersion measure, short period and low flux density. All of these pulsars have strong linear polarization with a mean value of 47% and no previously published polarization data.

Polarization observations of four southern pulsars at 1560 MHz

We present some interesting results from the mean pulse polarization observations of four southern pulsars made at the Australian National Radio Astronomy Observatory, Parkes, using the 64-m telescope in June and July, 1988. The 2 × 16 × 5 MHz filter system from Jodrell Bank has proved excellent in de-dispersing the pulse signals and measuring their polarization properties. We give the data for the four pulsars in some detail and discuss their spectral behaviour.

Polarization observations of 17 southern pulsars at 600 MHz

Pulse profiles of 17 pulsars showing the polarization characteristics at frequencies near 600 MHz are presented. Sixteen of these pulsars were discovered in the second Molonglo survey, while PSR 0539−66 is a pulsar in the Large Magellanic Cloud. The polarization data were analysed to determine the rotation measures of the pulsars

A search for interpulses from southern pulsars

Les resultats d'une recherche des interpulsations de 38 pulsars observables de l'hemisphere sud sont presentes. Une interpulsation a ete decouverte dans PSR 1702-19 et des observations sur une grande etendue de frequences suggerent que son axe magnetique est perpendiculaire a son axe de rotation. La pulsation principale et l'interpulsation de ce pulsar paraissent provenir du centre de la region de la calotte polaire

Cooperation in astronomy between Indonesia and Japan

The cooperation programme in astronomy between Indonesia and Japan is presented as an example of a well-coordinated bilateral cooperation between Asian countries. This cooperation has started in 1979, in the fields of galactic astronomy and stellar physics. The form of the cooperation is principally the exchange of persons between both countries for the purposes of collaborative works in some specific fields, the training of young astronomers, and technical cooperation. The main subjects of collaborative works are: (1) survey of red giants in the galactic center region, (2) survey of Hα-emission stars in some areas of the sky, (3) theoretical study of the dynamical evolution of stellar systems, (4) photoelectric observations of southern close binaries, (5) X-ray binaries and pulsars, (6) Be stars, and (7) other topics. The organization and main results of these works are presented, along with a future aspect of the cooperation.

Optical observations of southern pulsars

Optical observations of southern pulsars

A Search for Pulsed Gamma Emission from Two Pulsars

We have recently used the atmospheric air-shower Cerenkov technique in an attempt to observe pulsed gamma radiation from two southern pulsars, PSR 0833—45 and MP 0959. Northern hemisphere observers do not agree whether the pulsars CP 0950, CP 1133 and CP 1919 are sources of gamma emission, either pulsed or uniform in time.

Discovery of Two Southern Pulsars

Two southern pulsars have been discovered by observations at the Molonglo Radio Observatory. One is within 3° of the direction of the galactic centre. Preliminary values for the positions and pulse periods are given in Table 1.