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Parkes observations for project P976 semester 2018APRS_12
Spider pulsars - black widows (BW) and redbacks (RB) - reside in incredibly tight orbits with low-mass stellar companions. The close proximity of the two orbiting bodies leads to heavy irradiation of the companion by the pulsar wind, causing material to be driven from its surface. This excess material is not gravitationally bound to the star, and t... morehe extent to which it reaches can only be constrained by observing the duration of eclipses of the radio pulsar emission that it causes. Little information about these systems is set in stone: the physical processes behind the eclipses, the dimensions, densities and magnetic properties of the eclipse medium, mass loss rates and subsequent evolution of the companions, are all unknown. Previous radio studies of a handful of spider systems have highlighted the importance of high-time resolution and large frequency coverage in constraining their properties. Measurement of the flux density, dispersion measure, rotation measure and depolarisation of the pulsars, as a function of the orbits, directly probes the eclipse process and properties of the medium causing it. All of these measurables are frequency dependent, thus with ultra-wideband observations we will have access to an unparalleled insight into spider pulsar systems. We plan to observe three eclipses for each of three BWs and two RBs in order to constrain variability between the two classes, multiple systems within each class, and the eclipses in an individual system. In addition, such observations will demonstrate and help to optimise the capabilities of the new UWL receiver. less
Astronomical and Space Sciences not elsewhere classified
01 Apr 2018
31 Mar 2021
Creative Commons Attribution 4.0 International Licence
Polzin, Elliott; Johnston, Simon; Roberts, Mallory; Oslowski, Stefan; Sobey, Charlotte; Breton, Rene (2018): Parkes observations for project P976 semester 2018APRS_12. v1. CSIRO. Data Collection.
All Rights (including copyright) CSIRO 2018.
Access to this collection's metadata and/or files (if any) are restricted until 30 Mar 2020.
Australia Telescope National Facility
P976 - Wide-band characterisation of the radio eclipses of black widows and redbacks
Millisecond pulsars are remnants of supernova explosions that, despite being only 20 km in diameter, are more massive than the Sun. Their name arises from the fact that they spin so fast as to complete a rotation once every few milliseconds. Beams of radio waves are emitted from their magnetic poles, which we can detect on Earth as a pulse as the b... moreeam passes over us every rotation of the pulsar. Here we are observing a millisecond pulsar in a binary system with a more light-weight companion star. The two bodies orbit so close to one another that the companion star is evaporated by the wind from the pulsar, causing a cloud of material to surround the companion star that can eclipse the radio waves that we usually detect. These eclipses happen once every orbit, and we aim to determine the properties of the evaporated material, and the mechanisms through which it eclipses the pulsar beams. less