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The paucity of known intermittent pulsars makes individual studies valuable from the perspective of understanding how these pulsars emit and how that emission is changing in time and as a function of ... more frequency. The inherent difficulty in detecting these objects implies that their small population may well simply be a sampling bias, thus studying individual examples in details is fundamentally important in developing a complete understanding of the Galactic population. The Ultra-Wide-Band receiver and the MEDUSA backend provide unprecedented frequency coverage and will allow us to study the emission of the intermittent pulsar J1107-5907 in great detail. In particular, we will focus on the spectral characteristics of the emission, the frequency dependence of emission rates and the time scales on which the emission state switching occurs. By constraining the intermittency time scales we will be able to comment on model predictions, while the spectral index analysis will provide insights into the emission mechanism itself.less
Australia Telescope National Facility - P1013 - An ultra-wide-band study of the intermittent pulsar J1107-5907 - Published 10 Oct 2019
Stellar flares and coronal mass ejections (CMEs) may significantly impact the habitability of their planetary companions. M-dwarfs are particularly interesting in this regard, as they are known to fla... more re more frequently and powerfully than the Sun, and a large fraction of them are likely to host planets within their habitable zones. To fully characterise the impact of stellar activity and space weather events on companion planets, a sustained, multi-wavelength campaign is required to trace particle acceleration and energisation occurring in distinct regions of the stellar magnetosphere. The discovery of an Earth-like exoplanet orbiting within the ‘habitable zone’ of the active M-dwarf Proxima Centauri has spurred renewed interest of this system in the literature. At just 1.3 pc away, this system is ideal for developing our understanding of the impact of space weather events on Earth-like planets around active stars. As part of a large, multi-wavelength international campaign we are proposing 60 hours of Parkes Radio Telescope observations targeting Proxima Centauri, using the new UWL receiver. The large instantaneous bandwidth and high time-resolution capability of the Parkes UWL receiver will allow us to comprehensively characterise radio bursts at gigahertz frequencies. This will provide important diagnostics of the magnetospheric environment of this star, and may enable direct observation of space weather events such as CMEs. If successful, these observations will be a key part of an extensive campaign that will significantly improve our understanding of our nearest stellar neighbour.less
Australia Telescope National Facility - P1018 - Wide-band radio monitoring of space weather on Proxima Centauri - Published 10 Oct 2019
The spatial distribution of neutral gas is important for understanding the interstellar medium (ISM) evolution and star formation. However, the distribution of Tiny Scale Atomic Structures (TSAS), esp... more ecially the extremely small scale structures with spatial scales ranging from a few to hundreds of AU are largely unexplored. The formation and evolution of TSAS are still on an active debate. Multi-epoch observations of HI absorption against pulsars are a tested, practical observational method to probe the TSAS, due to pulsar’s nature on-off state and proper motions of 1 to 100 AU per year. The new Parkes UWL receiver has a powerful capability to simultaneously observe not only the HI line, but nearly all the CH lines, the four L-band OH lines, several dozen C and H recombination lines, and possibly even denser tracers such as ammonia and formaldehyde. Detecting any of those along with the HI absorption would represent a major leap in our understanding of TSAS. A particularly interesting possibility is that we might discover molecular absorption associated with TSAS, which would then imply that TSAS are not transient structures. We thus propose two epoch observations, which are separated by about five months, for four bright pulsars with the new Parkes UWL receiver using multiple spectral windows for probing structures ranging from 0.5 to 500 AU, monitoring the evolution of a known TSAS traced by PSR B1557-50, and try and detect other interstellar molecules in the TSAS.less
Australia Telescope National Facility - P1014 - A Search For Small Scale Structures in the ISM (Few to Hundreds of AU Scales) Using the new Parkes UWL Receiver - Published 10 Oct 2019
This proposal intends to confirm 10 candidate pulsars in a certain dispersion measures (DMs) range. Using new machine learning ranking and image processing methods, we have identified new candidates (... more with relatively low dispersion measures) in the Parkes Multibeam Pulsar Survey (PMPS) data. The initial processing of the multibeam survey was so successful that relatively low S/N candidates were placed in a "tier 2" category and never followed-up for re-observation. We, therefore, expect that a large number of relatively weak pulsars with S/N ratios around 8 will later be identified as "real" pulsars. We have already shown, with previous observations, that two of our ranked candidates are pulsars that were missed by the previous processing of the survey and wish to carry out confirmation observation of the next ten of our top-ranked candidates. The new discoveries of low-DM pulsars will significantly improve our understanding of the nearby neutron star population, which may generate a gamma-ray background affecting all related experiments. Additionally, it will also improve our knowledge of the completeness of low DM pulsars in existing surveys, and in turn, help improve the design and performance of further pulsar search surveys. In the last round we were allocated 5 hours, but unfortunately, these were canceled because of the NASA Voyager Voyager tracking.less
Australia Telescope National Facility - P1012 - Confirming a Certain Dispersion Measures Range of Pulsar Candidates - Published 09 Oct 2019
We propose Parkes NAPA radio observations of PSR B1055-52 to be carried out simultaneously with approved X-ray observations by XMM-Newton. We will look for radio-X-ray correlations in the pulse behavi... more or. In particular, we will search for a correlation of the X-ray pulse intensity with the very unusual quasi-periodic on/off change in the radio pulse intensity. These quasi-periodic changes on short timescale (about 20 periods) are also phase-locked between interpulse and main pulse, indicating global magnetospheric rearrangements. While radio-X-ray correlations have been detected in two older pulsars, they occur on much longer timescales. PSR B1055-52 provides a rare opportunity to search for the short-term manifestations of similar global processes in the radio and X-ray light curves. This radio- and X-ray- bright pulsar also shows some interesting long-term flux variability which we will investigate.less
Australia Telescope National Facility - P1010 - Probing for radio - X-ray correlations in the pulse profile of PSRB1055-52 - Published 09 Oct 2019
We propose to conduct observations of PSRs J1812-15 and J1831-04, a pair of 1-s pulsars which exhibit both nulling behaviour and clear evidence of acceleration, suggesting that they are in binary syst... more ems. Binary pulsars are valuable objects of scientific study, allowing for a wide range of applications, including tests of gravity, probes of the neutron star equation of state and fossil records of stellar evolution. Long spin-period pulsars in binary systems are generally much rarer than faster-spinning recycled pulsars, and represent an under-explored region of pulsar binary evolution.
Due to the nulling behaviour of both PSRs J1812-15 and J1831-04, determination of an orbital or phase-connected solution has so far proved impossible, but both of these steps are vital in allowing for their continued study. We propose a targeted, high-cadence observing campaign designed to map the orbits of these pulsars while simultaneously factoring in the redundancy required in order to overcome their nulling behaviour. By studying these pulsars, we hope to provide new insight into an unusual class of pulsar binary, as well to constrain the nulling properties of both pulsars.less
Australia Telescope National Facility - P1005 - Mapping the orbits of two nulling, long spin-period pulsars - Published 09 Oct 2019
Pulsars with features in their radio spectra, such as curvature or breaks seem to be special cases among the known pulsar population, with only about 20 per cent exhibiting them. Unfortunately, reliab... more le flux density measurements besides at 1.4 GHz are often unavailable, so that their spectral morphologies and features cannot be determined accurately. We propose to utilize the unique capabilities of the newly commissioned UWL receiver at the Parkes telescope, its extremely wide instantaneous frequency coverage from about 700 to 4000 MHz together with its high sensitivity, to determine the spectra of 26 radio pulsars. These have previously been identified to exhibit spectral features or show hints thereof. The new Parkes data are crucial to determine their spectral morphologies in that frequency range, to characterize their spectral features and to resolve these within the recorded bandwidth. Our aim is to understand the physical origin of the features, namely, whether these are perhaps intrinsic to the pulsar emission in these sources, are caused by absorption processes inside the pulsar's magnetosphere, or along the line of sight.less
Australia Telescope National Facility - P1011 - A wideband survey of pulsars with spectral features - Published 08 Oct 2019
Recently, extreme plasma lensing of pulsar emission has been observed in two eclipsing binaries, PSR B1957+20 and PSR B1744-24A. These lensing events are an extremely sensitive probe of pulsar emissi... more on, resolving physical scales of ~10 km at the pulsar, and can be used to measure the magnetization of the intrabinary material, and constrain outflow velocities and mass-loss rates of the binaries. We propose to observe the 5 brightest eclipsing pulsars (B1718-19, J1723-2837, B1744-24A, B1957+20, J2051-0827), to search for the effects of plasma lensing, and to make use of the new Parkes Ultra Wide Band Low Frequency (UWL) receiver, which will allow us to resolve lensing events in frequency and time, which is crucial for constraining physical parameters. This study will help determine how ubiquitous the effects of plasma lensing are in eclipsing binaries, put improved physical scales on the locations of pulsar emission, and help shed light on the nature of eclipses and evolutionary pathways of these systems.less
Australia Telescope National Facility - P1007 - An Ultra Wide-Band study of plasma lensing in eclipsing binaries - Published 08 Oct 2019
Magnetic field measurements of the Solar wind (SW) are extremely challenging, especially at close angular distances from the Sun. If they are obtained by measuring Faraday rotation of the radiation of... more background sources like active galactic nuclei, they are typically dependent on models of the electron density distribution in the heliosphere. However, pulsars can provide simultaneous, model-independent measurements of the electron density along the line-of-sight, along with Faraday Rotation estimates, and thus direct measurements of the SW magnetic field.
Moreover, high-precision pulsar timing experiments such as Pulsar Timing Arrays (PTAs) can be strongly affected by the free electron distribution in the SW, and it is fundamentally important to understand, model and mitigate its influence on PTAs signals.
With this proposal we aim to obtain high-cadence and precise measurements of the magnetic field and the electron density distribution of the SW by tracking three pulsars with low- to mid-ecliptic latitudes during their Solar approaches, and to reconstruct the SW dependence on the heliographic latitude. This will allow us to characterise the magnetic field of the SW and to collect precious information about the short-term fluctuations in the electron density that can appear as correlated noise in PTAs.less
Australia Telescope National Facility - P1008 - Tracking the Solar wind with pulsars - Published 08 Oct 2019
We propose observations with the ultra-wide-bandwidth, low-frequency receiver installed at the Parkes telescope to carry out the first ultra-high time resolution, coherently de-dispersed search for pu... more lsars in globular clusters. We have chosen the 11 most likely clusters for new discoveries. These clusters all have at least three pulsars already known allowing us to have a precise estimate of the pulsar dispersion measures and our observations will provide the first ultra-wide-bandwidth observation of these pulsars. Our observing strategy will enable us to search for extremely narrow pulsars and even pulsars with sub-millisecond periods.less
Australia Telescope National Facility - P1006 - The first ultra-high time resolution coherently de-dispersed search for new pulsars in globular clusters - Published 08 Oct 2019
A fundamental property of any astronomical source is its flux density. The new Parkes ultra-widebandwidth receiver is ideal for studying pulsar profiles and measuring flux densities over wide bands. ... more We have identified pulsars that can be observed by Parkes, but have no flux density measurements in the catalogue. Our proposal is simple - we wish to measure the pulsar flux densities, publish them and then later use those measurements to study pulsar populations, luminosities and to aid planning new pulsar surveys and commissioning activities.less
Australia Telescope National Facility - P1004 - Wide-band receiver observations of bright pulsars: Flux density measurements - Published 08 Oct 2019
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... more e 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 07 Oct 2019
This project is to continue timing and profile studies of the first double-pulsar system, a unique laboratory for gravitational physics. Recent results, including the first measurements of higher-orde... more r light-propagation effects and of the relativistic deformation of the orbit, highlight the importance of a long term observational campaign for this remarkable system. The main aims of this proposal are to provide the strongest tests to date for general relativity and to measure for the first time the moment-of-inertia of a neutron star. Additionally, we will determine the system geometry and map the pulsar beams via geodetic precession. Whenever possible, we will exploit the high sensitivity of the new UWL receiver.less
Australia Telescope National Facility - P455 - Timing & geodetic precession in the double pulsar and two
relativistic binaries - Published 07 Oct 2019
This project is to continue timing and profile studies of the first double-pulsar system, a unique laboratory for gravitational physics. Recent results, including the first measurements of higher-orde... more r light-propagation effects and of the relativistic deformation of the orbit, highlight the importance of a long term observational campaign for this remarkable system. The main aims of this proposal are to provide the strongest tests to date for general relativity and to measure for the first time the moment-of-inertia of a neutron star. Additionally, we will determine the system geometry and map the pulsar beams via geodetic precession. Whenever possible, we will exploit the high sensitivity of the new UWL receiver.less
Australia Telescope National Facility - P455 - Timing & geodetic precession in the double pulsar and two
relativistic binaries - Published 07 Oct 2019
Magnetic field measurements of the Solar wind (SW) are extremely challenging, especially at close angular distances from the Sun. If they are obtained by measuring Faraday rotation of the radiation of... more background sources like active galactic nuclei, they are typically dependent on models of the electron density distribution in the heliosphere. However, pulsars can provide simultaneous, model-independent measurements of the electron density along the line-of-sight, along with Faraday Rotation estimates, and thus direct measurements of the SW magnetic field.
Moreover, high-precision pulsar timing experiments such as Pulsar Timing Arrays (PTAs) can be strongly affected by the free electron distribution in the SW, and it is fundamentally important to understand, model and mitigate its influence on PTAs signals.
With this proposal we aim to obtain high-cadence and precise measurements of the magnetic field and the electron density distribution of the SW by tracking three pulsars with low- to mid-ecliptic latitudes during their Solar approaches, and to reconstruct the SW dependence on the heliographic latitude. This will allow us to characterise the magnetic field of the SW and to collect precious information about the short-term fluctuations in the electron density that can appear as correlated noise in PTAs.less
Australia Telescope National Facility - P1008 - Tracking the Solar wind with pulsars - Published 07 Oct 2019
Magnetic field measurements of the Solar wind (SW) are extremely challenging, especially at close angular distances from the Sun. If they are obtained by measuring Faraday rotation of the radiation of... more background sources like active galactic nuclei, they are typically dependent on models of the electron density distribution in the heliosphere. However, pulsars can provide simultaneous, model-independent measurements of the electron density along the line-of-sight, along with Faraday Rotation estimates, and thus direct measurements of the SW magnetic field.
Moreover, high-precision pulsar timing experiments such as Pulsar Timing Arrays (PTAs) can be strongly affected by the free electron distribution in the SW, and it is fundamentally important to understand, model and mitigate its influence on PTAs signals.
With this proposal we aim to obtain high-cadence and precise measurements of the magnetic field and the electron density distribution of the SW by tracking three pulsars with low- to mid-ecliptic latitudes during their Solar approaches, and to reconstruct the SW dependence on the heliographic latitude. This will allow us to characterise the magnetic field of the SW and to collect precious information about the short-term fluctuations in the electron density that can appear as correlated noise in PTAs.less
Australia Telescope National Facility - P1008 - Tracking the Solar wind with pulsars - Published 07 Oct 2019
We propose to continue the PULSE@Parkes project in which high school students from Australia and around the World use the Parkes radio telescope in a remote observing model to observe and analyse puls... more ar data. The data from some PULSE@Parkes observations are used to support the FERMI Gamma ray mission, other observations supplement the P456 Pulsar Timing Array project and the remainder were chosen in order to make a detailed analysis of pulsar timing irregularities and intermittency.less
Australia Telescope National Facility - P595 - PULSE@Parkes (Pulsar Student Exploration at Parkes) - Published 07 Oct 2019
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... more ur 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 07 Oct 2019
This proposal relates to time purchased by the Chinese Academy of Sciences for Parkes follow-up confirmation and timing of FAST discoveries. As the observing time has been purchased this proposal (an... more d the related PX501) does not require TAC grading. The primary reason for submitting a proposal is to ensure an outreach statement and that the proposal is entered into OPAL for the data archive to access. The Chinese team have two time requests. The time scheduled for the first, relating to this proposal, will be allocated in blocks of 24 hours and the data will become available in the data archive with an 18 month embargo period. The second type of time will be scheduled in shorter blocks and the data archived with a 10 year embargo.less
Australia Telescope National Facility - PX500 - FAST: category 1 purchased time - Published 07 Oct 2019
SUPERBx looks at the highest Galactic latitudes in a search for pulsars and fast radio bursts (FRBs). We use optimised GPU codes and supercomputing to search for these, making discoveries in real time... more . Handling our data as it comes in is essential for the SKA Phase I era so this work applies directly to the high-data rates of next generation telescopes. Our pulsar discoveries are typically nearby scintillating sources, intermittent sources and those in interesting binary systems. Our FRB discoveries have discovery lags of ~1 second, rather than months/years and these feed rapid alerts to the world-wide follow-up community via a dedicated VOEvent format an Astronomer's Telegrams. The goal of this is to allow localisation of the discovered FRBs. This is key for identifying FRB host galaxies, so as to solve the mystery of their progenitors and to exploit their many uses as tools for precision cosmology measurements.less
Australia Telescope National Facility - P892 - SUPERBx - The SUrvey for Pulsars & Extragalactic Radio Bursts Extension - Published 07 Oct 2019
This is a request for observing time for the initial follow-up of pulsar discoveries from the low-latitude Galactic plane section of the HTRU survey (P630). We have now completed a first pass processi... more ng of the entire survey with our periodicity search algorithm as well as the partially-coherent segmented acceleration search pipeline, and have discovered 106 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 ?eld strength, spin-down rate, as well as to detect any unexpected behaviour of the pulsar which might result from emission instabilities.
This follow-up 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 - P860 - Initial Follow-up of Pulsar Discoveries from the HTRU Galactic Plane Survey - Published 06 Oct 2019
This proposal intends to confirm 10 candidate pulsars in a certain dispersion measures (DMs) range. Using new machine learning ranking and image processing methods, we have identified new candidates (... more with relatively low dispersion measures) in the Parkes Multibeam Pulsar Survey (PMPS) data. The initial processing of the multibeam survey was so successful that relatively low S/N candidates were placed in a "tier 2" category and never followed-up for re-observation. We, therefore, expect that a large number of relatively weak pulsars with S/N ratios around 8 will later be identified as "real" pulsars. We have already shown, with previous observations, that two of our ranked candidates are pulsars that were missed by the previous processing of the survey and wish to carry out confirmation observation of the next ten of our top-ranked candidates. The new discoveries of low-DM pulsars will significantly improve our understanding of the nearby neutron star population, which may generate a gamma-ray background affecting all related experiments. Additionally, it will also improve our knowledge of the completeness of low DM pulsars in existing surveys, and in turn, help improve the design and performance of further pulsar search surveys. In the last round we were allocated 5 hours, but unfortunately, these were canceled because of the NASA Voyager Voyager tracking.less
Australia Telescope National Facility - P1012 - Confirming a Certain Dispersion Measures Range of Pulsar Candidates - Published 06 Oct 2019
Fast radio bursts (FRBs) continue to raise more questions than they answer. Until a few months ago, only one burst – the only one known to repeat - had been localized to a bright radio nebula (either... more a young supernova remnant or pulsar wind nebulae) in a distant dwarf galaxy.
Over the last year searches with the Australian Square Kilometre Array Pathfinder (ASKAP) have detected 28 bursts, two of which have been localised to host galaxies at redshifts > 0.3. These bursts and their hosts are very unlike the repeater, suggesting there may be a dichotomy in the population. Over the next six months we expect to detect another 12 FRBs, which will also have sub-arcsecond localisations. Here we propose to search this population for repeats. Our comprehensive sample and a dense monitoring campaign of well localised bursts, at a fluence limit more than 60 times lower than that of their detections, will either confirm the presence of additional repeating FRBs or the uniqueness of FRB 121102 amongst the population.less
Australia Telescope National Facility - P958 - Searching for repetition from ASKAP fast radio bursts - Published 06 Oct 2019
SUPERBx looks at the highest Galactic latitudes in a search for pulsars and fast radio bursts (FRBs). We use optimised GPU codes and supercomputing to search for these, making discoveries in real time... more . Handling our data as it comes in is essential for the SKA Phase I era so this work applies directly to the high-data rates of next generation telescopes. Our pulsar discoveries are typically nearby scintillating sources, intermittent sources and those in interesting binary systems. Our FRB discoveries have discovery lags of ~1 second, rather than months/years and these feed rapid alerts to the world-wide follow-up community via a dedicated VOEvent format an Astronomer's Telegrams. The goal of this is to allow localisation of the discovered FRBs. This is key for identifying FRB host galaxies, so as to solve the mystery of their progenitors and to exploit their many uses as tools for precision cosmology measurements.less
Australia Telescope National Facility - P892 - SUPERBx - The SUrvey for Pulsars & Extragalactic Radio Bursts Extension - Published 06 Oct 2019
SUPERBx looks at the highest Galactic latitudes in a search for pulsars and fast radio bursts (FRBs). We use optimised GPU codes and supercomputing to search for these, making discoveries in real time... more . Handling our data as it comes in is essential for the SKA Phase I era so this work applies directly to the high-data rates of next generation telescopes. Our pulsar discoveries are typically nearby scintillating sources, intermittent sources and those in interesting binary systems. Our FRB discoveries have discovery lags of ~1 second, rather than months/years and these feed rapid alerts to the world-wide follow-up community via a dedicated VOEvent format an Astronomer's Telegrams. The goal of this is to allow localisation of the discovered FRBs. This is key for identifying FRB host galaxies, so as to solve the mystery of their progenitors and to exploit their many uses as tools for precision cosmology measurements.less
Australia Telescope National Facility - P892 - SUPERBx - The SUrvey for Pulsars & Extragalactic Radio Bursts Extension - Published 05 Oct 2019
