데이터셋 상세
호주
Mengting Liu - Parkes observations for project P1219 semester 2025APRS 02
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.
데이터 정보
연관 데이터
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.
Reynier Squillace - Parkes observations for project P1386 semester 2025OCTS 01
공공데이터포털
J0045-7319 is a B star/pulsar binary in the Small Magellanic Cloud (SMC) with an orbital period of 51 days. The system is highly eccentric, with a closest approach of only 6 B-star radii, and it offers an unusual probe into massive stars in the SMC. Although similar systems exhibit strong dispersion measure (DM) variation during periastron arising from the stellar wind, observations in 1996 on the Parkes 70 cm receiver found no evidence of a wind from the B star. We propose a new set of observations on the Ultra-Wide Low-frequency receiver (UWL) designed to measure the wind. A null result will decrease the known upper limit on the B-star wind's contribution to DM by a factor of 9.
Reynier Squillace - Parkes observations for project P1386 semester 2025OCTS 02
공공데이터포털
J0045-7319 is a B star/pulsar binary in the Small Magellanic Cloud (SMC) with an orbital period of 51 days. The system is highly eccentric, with a closest approach of only 6 B-star radii, and it offers an unusual probe into massive stars in the SMC. Although similar systems exhibit strong dispersion measure (DM) variation during periastron arising from the stellar wind, observations in 1996 on the Parkes 70 cm receiver found no evidence of a wind from the B star. We propose a new set of observations on the Ultra-Wide Low-frequency receiver (UWL) designed to measure the wind. A null result will decrease the known upper limit on the B-star wind's contribution to DM by a factor of 9.
Reynier Squillace - Parkes observations for project P1386 semester 2025OCTS 03
공공데이터포털
J0045-7319 is a B star/pulsar binary in the Small Magellanic Cloud (SMC) with an orbital period of 51 days. The system is highly eccentric, with a closest approach of only 6 B-star radii, and it offers an unusual probe into massive stars in the SMC. Although similar systems exhibit strong dispersion measure (DM) variation during periastron arising from the stellar wind, observations in 1996 on the Parkes 70 cm receiver found no evidence of a wind from the B star. We propose a new set of observations on the Ultra-Wide Low-frequency receiver (UWL) designed to measure the wind. A null result will decrease the known upper limit on the B-star wind's contribution to DM by a factor of 9.
Akash Anumarlapudi - Parkes observations for project P1382 semester 2025OCTS 08
공공데이터포털
The prevalence of millisecond pulsars (MSPs) in and around the Galactic center and the bulge has been one of the key questions in pulsar astronomy. In addition to finding more exotic and interesting binary systems at and around the Galactic center and bulge due to the enhanced density of stars/stellar remnants, MSPs are also proposed to be one of the candidates to explain the observed Fermi gamma-ray excess. However, most of the MSPs discovered so far are field (disk) MSPs or those in globular clusters. Initial steps towards addressing the question of Galactic center/bulge MSPs were made with the discovery of the first MSPs in a Galactic filament, but more progress comes from the discovery of a sample of MSPs around the Galactic center. Blind surveys targeting MSPs can suffer from many observational biases that smear the pulses due to binary acceleration, scattering from the enhanced density, and so on, which increases the parameter space for discovery and can sometimes make the problem intractable. However, if pulsar candidates can be identified reliably from imaging surveys, then targeted observations can make the problem tractable in identifying the pulsations. We followed up a sample of polarized sources identified in the MeerKAT bulge imaging survey and discovered a sample of 16 new MSPs. Here we request the timing observations of 8 interesting MSPs (a subset of our discovery sample), to study the binary nature of these sources and their potential inclusion in pulsar timing array efforts.
Akash Anumarlapudi - Parkes observations for project P1382 semester 2025OCTS 01
공공데이터포털
The prevalence of millisecond pulsars (MSPs) in and around the Galactic center and the bulge has been one of the key questions in pulsar astronomy. In addition to finding more exotic and interesting binary systems at and around the Galactic center and bulge due to the enhanced density of stars/stellar remnants, MSPs are also proposed to be one of the candidates to explain the observed Fermi gamma-ray excess. However, most of the MSPs discovered so far are field (disk) MSPs or those in globular clusters. Initial steps towards addressing the question of Galactic center/bulge MSPs were made with the discovery of the first MSPs in a Galactic filament, but more progress comes from the discovery of a sample of MSPs around the Galactic center. Blind surveys targeting MSPs can suffer from many observational biases that smear the pulses due to binary acceleration, scattering from the enhanced density, and so on, which increases the parameter space for discovery and can sometimes make the problem intractable. However, if pulsar candidates can be identified reliably from imaging surveys, then targeted observations can make the problem tractable in identifying the pulsations. We followed up a sample of polarized sources identified in the MeerKAT bulge imaging survey and discovered a sample of 16 new MSPs. Here we request the timing observations of 8 interesting MSPs (a subset of our discovery sample), to study the binary nature of these sources and their potential inclusion in pulsar timing array efforts.
Akash Anumarlapudi - Parkes observations for project P1382 semester 2025OCTS 02
공공데이터포털
The prevalence of millisecond pulsars (MSPs) in and around the Galactic center and the bulge has been one of the key questions in pulsar astronomy. In addition to finding more exotic and interesting binary systems at and around the Galactic center and bulge due to the enhanced density of stars/stellar remnants, MSPs are also proposed to be one of the candidates to explain the observed Fermi gamma-ray excess. However, most of the MSPs discovered so far are field (disk) MSPs or those in globular clusters. Initial steps towards addressing the question of Galactic center/bulge MSPs were made with the discovery of the first MSPs in a Galactic filament, but more progress comes from the discovery of a sample of MSPs around the Galactic center. Blind surveys targeting MSPs can suffer from many observational biases that smear the pulses due to binary acceleration, scattering from the enhanced density, and so on, which increases the parameter space for discovery and can sometimes make the problem intractable. However, if pulsar candidates can be identified reliably from imaging surveys, then targeted observations can make the problem tractable in identifying the pulsations. We followed up a sample of polarized sources identified in the MeerKAT bulge imaging survey and discovered a sample of 16 new MSPs. Here we request the timing observations of 8 interesting MSPs (a subset of our discovery sample), to study the binary nature of these sources and their potential inclusion in pulsar timing array efforts.
Prajwal Voraganti Padmanabh - Parkes observations for project P1381 semester 2025OCTS 02
공공데이터포털
The Galactic bulge is theorized to host a rich population of millisecond pulsars (MSPs), but direct detections have been severely hampered by high interstellar scattering, dispersion, and background noise near the Galactic center. These MSPs, if confirmed, would serve as powerful tools for testing gravity, studying dense matter, and probing gravitational waves. A key indirect tracer of this population is the Fermi GeV excess (FGE), an unresolved gamma-ray signal possibly originating from thousands of faint MSPs. However, the lack of direct detections has limited our ability to test this hypothesis. The MeerKAT Galactic Bulge Survey (MGBS) is the most sensitive pulsar search yet of this region, targeting the bulge MSP population. Early results from MGBS have already revealed several promising MSP candidates. We propose to use Murriyang to conduct targeted follow-up observations of three of the most compelling candidates from MGBS. Our goals are to confirm the pulsations, refine key parameters such as spectral indices and orbital characteristics, and strengthen their association with the bulge. Confirming even a handful of bulge MSPs would have wide-reaching impact: constraining the origin of the FGE, testing dark matter interpretations, refining models of Galactic structure, and improving predictions for low-frequency gravitational wave backgrounds. This proposal is a critical next step toward establishing a long-sought bulge MSP population and unlocking new physics from the inner Galaxy.
Akash Anumarlapudi - Parkes observations for project P1382 semester 2025OCTS 03
공공데이터포털
The prevalence of millisecond pulsars (MSPs) in and around the Galactic center and the bulge has been one of the key questions in pulsar astronomy. In addition to finding more exotic and interesting binary systems at and around the Galactic center and bulge due to the enhanced density of stars/stellar remnants, MSPs are also proposed to be one of the candidates to explain the observed Fermi gamma-ray excess. However, most of the MSPs discovered so far are field (disk) MSPs or those in globular clusters. Initial steps towards addressing the question of Galactic center/bulge MSPs were made with the discovery of the first MSPs in a Galactic filament, but more progress comes from the discovery of a sample of MSPs around the Galactic center. Blind surveys targeting MSPs can suffer from many observational biases that smear the pulses due to binary acceleration, scattering from the enhanced density, and so on, which increases the parameter space for discovery and can sometimes make the problem intractable. However, if pulsar candidates can be identified reliably from imaging surveys, then targeted observations can make the problem tractable in identifying the pulsations. We followed up a sample of polarized sources identified in the MeerKAT bulge imaging survey and discovered a sample of 16 new MSPs. Here we request the timing observations of 8 interesting MSPs (a subset of our discovery sample), to study the binary nature of these sources and their potential inclusion in pulsar timing array efforts.
Akash Anumarlapudi - Parkes observations for project P1382 semester 2025OCTS 07
공공데이터포털
The prevalence of millisecond pulsars (MSPs) in and around the Galactic center and the bulge has been one of the key questions in pulsar astronomy. In addition to finding more exotic and interesting binary systems at and around the Galactic center and bulge due to the enhanced density of stars/stellar remnants, MSPs are also proposed to be one of the candidates to explain the observed Fermi gamma-ray excess. However, most of the MSPs discovered so far are field (disk) MSPs or those in globular clusters. Initial steps towards addressing the question of Galactic center/bulge MSPs were made with the discovery of the first MSPs in a Galactic filament, but more progress comes from the discovery of a sample of MSPs around the Galactic center. Blind surveys targeting MSPs can suffer from many observational biases that smear the pulses due to binary acceleration, scattering from the enhanced density, and so on, which increases the parameter space for discovery and can sometimes make the problem intractable. However, if pulsar candidates can be identified reliably from imaging surveys, then targeted observations can make the problem tractable in identifying the pulsations. We followed up a sample of polarized sources identified in the MeerKAT bulge imaging survey and discovered a sample of 16 new MSPs. Here we request the timing observations of 8 interesting MSPs (a subset of our discovery sample), to study the binary nature of these sources and their potential inclusion in pulsar timing array efforts.