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Showing results for: [ Bhat, Ramesh ]
We propose timing observations of a new pulsar discovered with the MWA. Thanks to the interferometric advantages of the MWA and the unique design of our survey we were able to determine the pulsar's p... moreosition to <1 arcminute precision, thereby providing an opportunity for accelerated convergence of its timing solution and determine its spin and astrometric parameters. With an estimated luminosity ~0.1 mJy kpc^2 at 1.4 GHz, this may turn out to be a low-luminosity pulsar, of which only a handful are currently known. Observations with the ultra-wide band low-frequency receiver will help us further investigate this in detail through measurements flux densities and spectral index. We will also undertake polarimetric analysis of the new pulsar to better constrain the pulsar's geometry and emission properties.less
Australia Telescope National Facility - P1080 - Timing and polarimetry of PSR J0036-1033 - Published 15 Jan 2021
We propose timing observations of the relativistic pulsar - white-dwarf binary, PSR J1141$-$6545. This unique system offers access to a wide range of physics, from relativistic phenomena through pulsa... morer emission cone studies, to the structure and distribution of interstellar plasma along our line-of-sight. The Parkes Ultra Wide Band Low Frequency (UWL) receiver has opened up the possibility of performing the first-ever studies of its orbital dynamics at high temporal resolution. Our analysis of data obtained to date suggests that the pulsar will precess away from our line-of-sight before 2023. Hence, regular observations are crucial to maximize science outcomes with this source.less
Australia Telescope National Facility - P971 - Orbital dynamics and the intra-binary medium of PSR J1141-6545 - Published 15 Jan 2021
This is a request for observing time for the timing campaign of new pulsar discoveries and follow-up of expected new potential pulsars from the re-processing of the low-latitude Galactic plane section... more of the HTRU survey (P630). We have now completed the first pass re-processing of the 62 % of the survey with GPU based coherent acceleration search and template bank search pipelines, and have discovered 51 previously unknown pulsars. Interesting science can usually only be derived from a new pulsar after confirmation and a follow-up timing campaign is carried out. One year of initial timing is the minimum timespan required to fully characterise any newly-discovered pulsars, essential for deriving pulsar parameters such as the characteristic age, magnetic field strength, spin-down rate, as well as to detect any unexpected behaviour of the pulsar which might result from emission instabilities. This timing project is necessary for following up on any interesting pulsar systems discovered from the HTRU Galactic plane survey. Since all of the pulsars on the observing list here have been confirmed in the current 2020APRS semester, the follow-up timing will produce completely new and exciting results. In addition, this timing project will enable a large-scale examination of the Galactic plane pulsar population, exploring the true boundaries of pulsar parameter space in the galactic plane.less
Australia Telescope National Facility - P1050 - Initial Follow-up of Potential Pulsar Discoveries from Re-processing of the HTRU-S LowLat Galactic Plane Survey - Published 12 Jan 2021
The Parkes Pulsar Timing Array (PPTA) project has three primary goals: (a) detection of gravitational waves from astronomical sources, (b) establishment of a pulsar timescale, and (c) improvement of o... moreur understanding of Solar-system dynamics. The PPTA is the oldest of three international pulsar timing groups. We have the smallest telescope and the smallest group, but the best measurements and the best results. Our bound on the strength of the incoherent gravitational wave background is the only bound which significantly constrains theoretical models. We have maintained our leading position because: we have the southern sky; we have a small but well-focussed group; we have the best-calibrated receivers; and we have been able to observe with an almost regular cadence of 15 to 20 days over a wide bandwidth. With this proposal we aim to maintain our pre-eminent position in the field. Unlike most observing proposals, this is a continuing proposal for which the observations will continue to improve bounds on ultra-low-frequency gravitational waves until they are finally detected. Continued Parkes observations will remain valuable at least until the first stage of the SKA is able to improve on our sensitivity and observing cadence. Even after the gravitational wave background is detected we will want to continue observations in support of the nascent field of gravitational wave astronomy!less
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 12 Jan 2021
Australia Telescope National Facility - P1050 - Initial Follow-up of Potential Pulsar Discoveries from Re-processing of the HTRU-S LowLat Galactic Plane Survey - Published 08 Jan 2021
Australia Telescope National Facility - P1050 - Initial Follow-up of Potential Pulsar Discoveries from Re-processing of the HTRU-S LowLat Galactic Plane Survey - Published 05 Jan 2021
Australia Telescope National Facility - P1080 - Timing and polarimetry of PSR J0036-1033 - Published 05 Jan 2021
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 05 Jan 2021
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 03 Jan 2021
Australia Telescope National Facility - P1050 - Initial Follow-up of Potential Pulsar Discoveries from Re-processing of the HTRU-S LowLat Galactic Plane Survey - Published 01 Jan 2021
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 23 Dec 2020
This is a request for observing time for the initial follow-up of pulsar discoveries from the re-processing of the low-latitude Galactic plane section of the HTRU survey (P630). We have now completed ... morea first pass re-processing of the 60 % of the survey with GPU based coherent acceleration search and template bank search pipelines, and have discovered potential 54 previously unknown pulsars. Interesting science can usually only be derived from a new pulsar after confirmation and a follow-up timing campaign is carried out. One year of initial timing is the minimum timespan required to fully characterise any newly-discovered pulsars, essential for deriving pulsar parameters such as the characteristic age, magnetic field strength, spin-down rate, as well as to detect any unexpected behaviour of the pulsar which might result from emission instabilities. This follow-up and timing project is necessary for following up on any interesting pulsar systems discovered from the HTRU Galactic plane survey. Since all of the pulsars on the observing list here are being followed-up for the first time, they will produce completely new and exciting results. In addition, this timing project will enable a large-scale examination of the Galactic plane pulsar population, exploring the true boundaries of pulsar parameter space.less
Australia Telescope National Facility - P1050 - Initial Follow-up of Potential Pulsar Discoveries from Re-processing of the HTRU-S LowLat Galactic Plane Survey - Published 22 Dec 2020
After five decades of study, the physics of radio wave emission and propagation in the pulsar magnetosphere remains poorly understood. This is largely due to the wide variety of dynamic phenomena obs... moreerved in pulsar signals that are neither predicted nor explained by current theory, the limited window of the pulsar spectrum that previously could be studied simultaneously, and the biased sample of the pulsar population that has been studied to date. To address these limitations, we have developed pioneering statistical methods that provide new interpretive insights and enable us to study the dynamics of the radio pulsar signal on short time scales (e.g. drifting and quasi-periodic sub-pulse structure, transitions between orthogonally polarized modes of emission, nulling, etc.) even when individual pulses cannot be detected. Using our novel methods and the ultra-wide bandwidth receiver at Parkes, we will undertake a large-scale survey of pulsar radio emission statistics and explore two previously inaccessible regions where pulsar flux densities are typically much lower: the pulsar spectrum above 2 GHz, and the recycled pulsar population. Measuring the instantaneous bandwidth of impulsive emission events will yield new constraints on the physical conditions in the pulsar magnetosphere, such as the spatial scale of strong turbulence in the magnetospheric plasma. The breadth of our sample, from millisecond pulsars to magnetars, will enable us to study the evolution of emission and propagation physics over four orders of magnitude in magnetospheric size and seven orders of magnitude in magnetic field strength.less
Australia Telescope National Facility - P1052 - Pulsar Radio Emission Statistics Survey (PRESS) - Published 21 Dec 2020
We propose timing observations of the relativistic pulsar - white-dwarf binary PSR J1141-6545. This unique system offers access to a wide range of physics, from relativistic phenomena through pulsar e... moremission cone studies, to the structure and distribution of interstellar plasma along our line-of-sight. The recently installed Parkes Ultra Wide Band Low Frequency (UWL) receiver has opened up the possibility of performing first-ever studies of its orbital dynamics at high temporal resolution and study of the effects of the intra-binary medium on the dispersion and polarisation of the pulse profile. Our analysis of data obtained to date suggests that the pulsar would precess away from our line-of-sight in the next 3-5 years. Hence, regular observations are crucial to maximizing its science outcomeless
Australia Telescope National Facility - P971 - Orbital dynamics and the intra-binary medium of PSR J1141-6545 - Published 20 Dec 2020
Since the year 2005, the Parkes Pulsar Timing Array (PPTA) project has been placing ever more stringent constraints on the amplitude of a gravitational wave background signal. Such upper bounds on th... moree amplitude of the gravitational wave signal are currently dominated by a single pulsar: PSR J1909-3744. The upper bound with this pulsar alone already cuts into the range of tenable theoretical models. Further reducing the amplitude bound (by continued regular observations of this pulsar) will significantly narrow that range. The first evidence of gravitational waves in the pulsar data are likely to be observed in the timing for PSR J1909-3744, but with only a single pulsar we will not be able to make an unambiguous detection. However, knowledge of the likely signal strength (derived from this pulsar) will help to optimise the observing strategy for the detection of the gravitational wave signals with existing or future pulsar timing arrays.less
Australia Telescope National Facility - P895 - Where are the gravitational waves? - Published 19 Dec 2020
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 19 Dec 2020
Australia Telescope National Facility - P971 - Orbital dynamics and the intra-binary medium of PSR J1141-6545 - Published 08 Dec 2020
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 07 Dec 2020
Australia Telescope National Facility - P1050 - Initial Follow-up of Potential Pulsar Discoveries from Re-processing of the HTRU-S LowLat Galactic Plane Survey - Published 03 Dec 2020
Australia Telescope National Facility - P895 - Where are the gravitational waves? - Published 01 Dec 2020
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 30 Nov 2020
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 28 Nov 2020
Australia Telescope National Facility - P1050 - Initial Follow-up of Potential Pulsar Discoveries from Re-processing of the HTRU-S LowLat Galactic Plane Survey - Published 03 Nov 2020
Australia Telescope National Facility - P456 - A millisecond pulsar timing array - Published 02 Nov 2020
Australia Telescope National Facility - P1050 - Initial Follow-up of Potential Pulsar Discoveries from Re-processing of the HTRU-S LowLat Galactic Plane Survey - Published 31 Oct 2020
