Magnetars are neutron stars with exceptionally high magnetic fields. From the 30 known magnetars, only six have had radio emission detected so far. The remaining 24 magnetars are generally only searched for radio emission after an X-ray outburst. This added a strong selection bias to whether magnetars are radio loud or not. From the known six radio loud magnetars, we know that the radio emission changes quickly with time and for the magnetar XTE J1810-197, it has been observed that the radio flux increases strongly without an enhancement in X-ray flux. Thus, it remains unclear whether the radio quiet magnetars are in fact radio quiet and the radio X-ray relation appears to be rather complex. In this proposal, we propose a regular monitoring campaign of 4 radio quiet magnetars with bi-weekly observations using the Parkes UWL receiver. For 3 of the sources, we will have accompanying X-ray observations and thus, this will give an unique data set to probe the relation between radio and X-ray independent outbursts. Any detection of radio emission, i.e. single pulses or folded profiles, would be a major discovery and help to constrain the emission mechanisms of magnetars. This will also help to improve the understanding of the emission mechanism of fast radio bursts. However, also a non-detection of radio emission will provide upper limits that serve as a baseline before any future outburst of the observed magnetars as well as allow to constrain the formation process of magnetars in contrast to pulsars.

Magnetars are neutron stars with exceptionally high magnetic fields. From the 30 known magnetars, only six have had radio emission detected so far. The remaining 24 magnetars are generally only searched for radio emission after an X-ray outburst. This added a strong selection bias to whether magnetars are radio loud or not. From the known six radio loud magnetars, we know that the radio emission changes quickly with time and for the magnetar XTE J1810-197, it has been observed that the radio flux increases strongly without an enhancement in X-ray flux. Thus, it remains unclear whether the radio quiet magnetars are in fact radio quiet and the radio X-ray relation appears to be rather complex. In this proposal, we propose a regular monitoring campaign of 4 radio quiet magnetars with bi-weekly observations using the Parkes UWL receiver. For 3 of the sources, we will have accompanying X-ray observations and thus, this will give an unique data set to probe the relation between radio and X-ray independent outbursts. Any detection of radio emission, i.e. single pulses or folded profiles, would be a major discovery and help to constrain the emission mechanisms of magnetars. This will also help to improve the understanding of the emission mechanism of fast radio bursts. However, also a non-detection of radio emission will provide upper limits that serve as a baseline before any future outburst of the observed magnetars as well as allow to constrain the formation process of magnetars in contrast to pulsars.

We propose a modest program to continue monitoring 4 of the 6 known radio magnetars in order to achieve three primary science goals. The first is to characterise magnetar outbursts over long timescales, for which tracking their rotational, flux density, and polarisation properties provide a clear view of the impulse response of their magnetic fields. Second, understanding the links between magnetars the mysterious fast radio burst phenomenon through the discovery of rare emission and propagation effects, shared spectro-temporal phenomenology, and connections to high-energy (X-ray/gamma-ray) phenomena. Lastly, our continued monitoring has enormous benefit to the wider magnetar community, providing rapid alerts to changes in activity, adding context to unusual behaviour detected by high-enery observations, and a host of supplementary science through the teams extensive collaborative networks. The project and its precursors have been running since 2007 and have contributed to 21 publications since then. We are seeking to convert the project to long-term status, thereby also carrying these investigations into the SKA era.

We propose a modest program to continue monitoring 4 of the 6 known radio magnetars in order to achieve three primary science goals. The first is to characterise magnetar outbursts over long timescales, for which tracking their rotational, flux density, and polarisation properties provide a clear view of the impulse response of their magnetic fields. Second, understanding the links between magnetars the mysterious fast radio burst phenomenon through the discovery of rare emission and propagation effects, shared spectro-temporal phenomenology, and connections to high-energy (X-ray/gamma-ray) phenomena. Lastly, our continued monitoring has enormous benefit to the wider magnetar community, providing rapid alerts to changes in activity, adding context to unusual behaviour detected by high-energy observations, and a host of supplementary science through the teams extensive collaborative networks. The project and its precursors have been running since 2007 and have contributed to 21 publications since then. We are seeking to convert the project to long-term status, thereby also carrying these investigations into the SKA era.

Dynamics Explorer 1 Magnetic Field Observations Triaxial Fluxgate Magnetometer at 6 second resolution.

Parker Solar Probe FIELDS Instrument Suite Fluxgate Magnetometer, MAG, Data: The time resolution of the MAG time series data varies with instrument mode ranging from 2.289 samples/s to 292.9 samples/s. These two data sampling rates corresponding to 2 samples or 256 samples per 0.874 s where 0.874 s is equal to 2^25 divided 38.4 MHz. See reference [2] for a complete explanation of the MAG instrument sampling methodology. The Magnetometer has four ranges: ±1024 nT, ±4096 nT, ±16,384 nT, and ±65,536 nT. The Magnetometer Range is selected by an algorithm based on the strength of the ambient magnetic field. The magnetic field measurement precision is ±15 bits, based on the 16-bit Analog to Digital Converter, ADC.References:* 1. Fox, N.J., Velli, M.C., Bale, S.D. et al. Space Sci Rev (2016) 204: 7. https://doi.org/10.1007/s11214-015-0211-6* 2. Bale, S.D., Goetz, K., Harvey, P.R. et al. Space Sci Rev (2016) 204: 49. https://doi.org/10.1007/s11214-016-0244-5

Magnetic fields are fundamental in regulating star formation and the evolution of molecular clouds. Zeeman splitting offers a unique method to directly measure line-of-sight magnetic field strengths in interstellar environments, from the diffuse ISM to dense cores. Observations of HI and OH absorption toward pulsars provide an unprecedented opportunity to measure magnetic fields with high precision, benefiting from pulsars' small angular sizes and reliable Stokes V spectra unaffected by instrumental effects. Our recent tentative Zeeman splitting detections in OH absorption toward PSR J1644-4559 with Parkes reveal magnetic field strengths that suggest magnetically subcritical states, where magnetic pressure counteracts gravity. This challenges conventional theories of subcritical cold neutral medium (CNM) transitioning to supercritical star-forming molecular clouds, emphasizing the need for detailed investigation. We propose a continuation of Zeeman splitting studies through high-sensitivity OH and HI absorption observations of pulsars PSR J1644-4559, J1721-3532, and J1852+0031 using Parkes. By employing an innovative phase-resolved spectral technique and extending integration times, we aim to enhance Zeeman detection sensitivity and study magnetic field transitions in the CNM and quiescent molecular clouds. This work will refine our understanding of subcritical-to-supercritical transitions in star formation, establish pulsar absorption as a robust probe of interstellar magnetic fields, and advance observational techniques critical to star formation studies.

Magnetic fields are fundamental in regulating star formation and the evolution of molecular clouds. Zeeman splitting offers a unique method to directly measure line-of-sight magnetic field strengths in interstellar environments, from the diffuse ISM to dense cores. Observations of HI and OH absorption toward pulsars provide an unprecedented opportunity to measure magnetic fields with high precision, benefiting from pulsars' small angular sizes and reliable Stokes V spectra unaffected by instrumental effects. Our recent tentative Zeeman splitting detections in OH absorption toward PSR J1644-4559 with Parkes reveal magnetic field strengths that suggest magnetically subcritical states, where magnetic pressure counteracts gravity. This challenges conventional theories of subcritical cold neutral medium (CNM) transitioning to supercritical star-forming molecular clouds, emphasizing the need for detailed investigation. We propose a continuation of Zeeman splitting studies through high-sensitivity OH and HI absorption observations of pulsars PSR J1644-4559, J1721-3532, and J1852+0031 using Parkes. By employing an innovative phase-resolved spectral technique and extending integration times, we aim to enhance Zeeman detection sensitivity and study magnetic field transitions in the CNM and quiescent molecular clouds. This work will refine our understanding of subcritical-to-supercritical transitions in star formation, establish pulsar absorption as a robust probe of interstellar magnetic fields, and advance observational techniques critical to star formation studies.