데이터셋 상세
호주
Ayan Biswas - LBA observations for project V653 semester 2024APRS
Roughly 1 in 10 O stars have been found to harbour extremely stable, ordered (usually dipolar) magnetic fields, which are of ~kG strength. The presence of such organized surface magnetic fields can channel and confine the outflowing stellar winds, creating a magnetosphere that can radiate in various wavebands. Several attempts were made to detect radio emissions from magnetic O-type stars at low frequencies. However, no detection was found, which can be explained by the absorption of non-thermal emission in sub-GHz frequencies due to the dense wind of such high mass-loss rate systems. The first exception to this scenario is the detection of sub-GHz radio emission with the upgraded Giant Metrewave Radio Telescope (uGMRT) from a binary O-star system HD 148937. The 325 MHz detection of this target makes it the lowest frequency detection of any magnetic massive star. The observed emission is non-thermal in nature, with radio luminosity much higher than expected. We attribute the possible emission mechanism to be either synchrotron emission from wind-wind collision, or Electron Cyclotron Maser Emission (ECME) from the magnetic primary. Given the extreme and unique nature of the radio emission from this system, we plan to follow up this target and make use of the high resolution of the LBA to pinpoint the emission region and the corresponding mechanism.
데이터 정보
연관 데이터
Marlon Bause - Parkes observations for project P1356 semester 2025APRS 17
공공데이터포털
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.
Mengting Liu - Parkes observations for project P1219 semester 2025APRS 15
공공데이터포털
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.
Fernando Camilo - Long-term project observations for project P885 semester 2025APRS 10
공공데이터포털
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.
Fernando Camilo - Long-term project observations for project P885 semester 2025APRS 14
공공데이터포털
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.
Fernando Camilo - Long-term project observations for project P885 semester 2025OCTS 01
공공데이터포털
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.
Fernando Camilo - Long-term project observations for project P885 semester 2025OCTS 02
공공데이터포털
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.
Runchao Chen - Parkes observations for project P1380 semester 2025OCTS 01
공공데이터포털
The association of FRB 200428 with the Galactic magnetar SGR 1935+2154 confirms that magnetars can power fast radio bursts (FRBs). However, FRB 200428 is 4 to 8 orders of magnitude less energetic than the typical population of cosmological FRBs. This discrepancy is likely due to the moderate magnetic field strength and evolved age of SGR 1935+2154. In contrast, newborn extragalactic magnetars, such as those formed in gamma-ray burst (GRB) central engines, are expected to have much stronger magnetic fields, more rapid spin-down, and highly dynamic magnetospheres, all of which favor the production of brighter and more frequent FRBs. We propose a targeted search for FRBs from the recently localized GRB 230307A, a long-duration GRB with evidence suggesting the formation of a young magnetar. Given the source's relatively close distance (291 Mpc) and possible youth (less than 3 years), it offers a compelling opportunity to test FRB generation mechanisms during the early evolution of a magnetar. We request 30 hours of observing time with the Parkes 64-m Murriyang telescope using the ultra-wideband low-frequency (UWL) receiver. Our plan includes one 10-hour long-duration session to detect rare or clustered bursts, and ten 2-hour sessions spread over 2-3 months to sample temporal variability. Data will be processed with state-of-the-art pipelines for single-pulse searches and coherent dedispersion. A detection would strongly support magnetar-origin FRB models and provide key constraints on the early-time activity of GRB-formed neutron stars.
Runchao Chen - Parkes observations for project P1380 semester 2025OCTS 02
공공데이터포털
The association of FRB 200428 with the Galactic magnetar SGR 1935+2154 confirms that magnetars can power fast radio bursts (FRBs). However, FRB 200428 is 4 to 8 orders of magnitude less energetic than the typical population of cosmological FRBs. This discrepancy is likely due to the moderate magnetic field strength and evolved age of SGR 1935+2154. In contrast, newborn extragalactic magnetars, such as those formed in gamma-ray burst (GRB) central engines, are expected to have much stronger magnetic fields, more rapid spin-down, and highly dynamic magnetospheres, all of which favor the production of brighter and more frequent FRBs. We propose a targeted search for FRBs from the recently localized GRB 230307A, a long-duration GRB with evidence suggesting the formation of a young magnetar. Given the source's relatively close distance (291 Mpc) and possible youth (less than 3 years), it offers a compelling opportunity to test FRB generation mechanisms during the early evolution of a magnetar. We request 30 hours of observing time with the Parkes 64-m Murriyang telescope using the ultra-wideband low-frequency (UWL) receiver. Our plan includes one 10-hour long-duration session to detect rare or clustered bursts, and ten 2-hour sessions spread over 2-3 months to sample temporal variability. Data will be processed with state-of-the-art pipelines for single-pulse searches and coherent dedispersion. A detection would strongly support magnetar-origin FRB models and provide key constraints on the early-time activity of GRB-formed neutron stars.