Periodic Reporting for period 4 - MeerTRAP (Discovering Fast Transients and Pulsars with MeerKAT for Cosmology and to Test the Laws of Gravity)
Período documentado: 2021-04-01 hasta 2022-09-30
The goal of the MeerTRAP project is to undertake commensal observations of the radio sky with the MeerKAT telescope to find new fast radio transients and pulsars. The short duration bursts of radio emission from these sources can be used to study the extremes of physics. The pulses detected from the rapidly spinning and highly magnetised pulsars can be used to understand the physics of the emission process, perform tests of gravity and to probe the ultra-dense matter equation of state. Transient and/or short-duration bursts of radio emission have been proposed to originate in a wide range of explosive events such as merging neutron stars, black hole formation and gamma-ray bursts and thus are excellent tools with which to study these phenomena. If these bursts occur at sufficient distances then they can also be used to understand the nature of the intervening material and also potentially the physical state of the Universe. In all cases these astrophysical objects provide us with tools to explore physics that cannot be studies in the laboratory.
To achieve this we use the extremely sensitive MeerKAT telescope to perform commensal radio observations. This provides us with the on-sky time needed to find these rare objects. In parallel we carry out optical searches using MeerLICHT to form unique radio-optical transient data sets. We also designed, build, and commission, the large compute cluster and associated software that is required to search the up to 800 simultaneous views of the sky. We generate triggers from these transients to capture data directly from MeerKAT which we can use to accurately localise them. MeerKAT is a pre-cursor telescope for the international SKAO project to build the world's largest radio telescope.
The innovative software that we are developing for processing, controlling and interpreting our data, including pipeline management, sifting algorithms and machine learning classifiers, will have applications beyond our field and we are therefore making them as public and user friendly as we can.
The overall objectives of MeerTRAP are:
- Discover and localise large numbers of FRBs over a wide range of redshifts to ascertain their nature through an understanding of their host galaxies and environments.
- Use these objects to study the intergalactic medium.
- Probe the nature of the transient and variable radio sky on many timescales to reveal new populations of radio transient objects.
- Perform multi-wavelength studies of these transients, uniquely including simultaneous data from MeerLICHT, as well as follow up with other facilities.
- Discover new radio pulsars, in particular those that might vary on all sorts of timescales due to emission, formation or binary properties and those with long periods.
To achieve this we use the extremely sensitive MeerKAT telescope to perform commensal radio observations. This provides us with the on-sky time needed to find these rare objects. In parallel we carry out optical searches using MeerLICHT to form unique radio-optical transient data sets. We also designed, build, and commission, the large compute cluster and associated software that is required to search the up to 800 simultaneous views of the sky. We generate triggers from these transients to capture data directly from MeerKAT which we can use to accurately localise them. MeerKAT is a pre-cursor telescope for the international SKAO project to build the world's largest radio telescope.
The innovative software that we are developing for processing, controlling and interpreting our data, including pipeline management, sifting algorithms and machine learning classifiers, will have applications beyond our field and we are therefore making them as public and user friendly as we can.
The overall objectives of MeerTRAP are:
- Discover and localise large numbers of FRBs over a wide range of redshifts to ascertain their nature through an understanding of their host galaxies and environments.
- Use these objects to study the intergalactic medium.
- Probe the nature of the transient and variable radio sky on many timescales to reveal new populations of radio transient objects.
- Perform multi-wavelength studies of these transients, uniquely including simultaneous data from MeerLICHT, as well as follow up with other facilities.
- Discover new radio pulsars, in particular those that might vary on all sorts of timescales due to emission, formation or binary properties and those with long periods.
We have undertaken detailed simulation work to ascertain that show that the properties of the present FRB observations cannot definitively rule out a single population of repeating bursts. We also simulated the number of FRBs one would need to be able to determine when the epoch of Helium reionization occurred. These works are both published.
We have carried out detailed studies of some known FRBs and magnetars and published them. We detected a periodicity in the burst rate for the first repeating FRB ever to be discovered. This could be indicative of a binary orbit for example and thus can help constrain the type of source, and emission mechanism, for some FRBs.
We discovered a very long period radio emitting neutron star that has revolutionised our understanding of the types of neutron stars which can emit radio emission and was published in Nature Astronomy. We since discovered sources spinning with periods of 10 and 17s establishing a population of the slowest spinning radio emitting neutron stars known and showing their may be a significant population.
We have detected 75 short-duration radio transients that are located in our Galaxy that are likely part of the population of radio emitting neutron stars known as RRATs, an increase of about 30%. We have published the first dozen and are working on publications of the remainder. We will be able to get accurate positions and also measure their spin parameters helping us to better characterise the nature of the RRAT population.
At the time of writing we have detected 36 FRBs which represents a large number of sources of interest because of the luminosity of our discoveries, dispersion measure/redshift range that we are able to probe and multiple frequencies. We have been able to localise a number of them and study the host galaxies, a crucial part of understanding FRBs and using them for cosmological studies. The first of our FRBs have been published and our first study of our population is currently with the referees. Our first precisely localised FRB and its probable host galaxy is in preparation. We are also pursuing optical follow up of the FRBs that we have been able to localise in images and are preparing associated publications.
We developed machine learning tools to classify transients in real time. Our triggering software enabled us to capture raw telescope data and accurately localise any new transients. We designed and built the pipeline to image these data sets and localise FRBs and transients. We developed a methodology and software to localise transients without the raw data. We also wrote a set of new software (and mathematical description) for removing Radio Frequency Interference. We established a new fast-folding algorithm which greatly enhances the sensitivity to searches for long-period radio pulsars and used it for a number of surveys. All our software is public and we have written associated publications.
We have carried out detailed studies of some known FRBs and magnetars and published them. We detected a periodicity in the burst rate for the first repeating FRB ever to be discovered. This could be indicative of a binary orbit for example and thus can help constrain the type of source, and emission mechanism, for some FRBs.
We discovered a very long period radio emitting neutron star that has revolutionised our understanding of the types of neutron stars which can emit radio emission and was published in Nature Astronomy. We since discovered sources spinning with periods of 10 and 17s establishing a population of the slowest spinning radio emitting neutron stars known and showing their may be a significant population.
We have detected 75 short-duration radio transients that are located in our Galaxy that are likely part of the population of radio emitting neutron stars known as RRATs, an increase of about 30%. We have published the first dozen and are working on publications of the remainder. We will be able to get accurate positions and also measure their spin parameters helping us to better characterise the nature of the RRAT population.
At the time of writing we have detected 36 FRBs which represents a large number of sources of interest because of the luminosity of our discoveries, dispersion measure/redshift range that we are able to probe and multiple frequencies. We have been able to localise a number of them and study the host galaxies, a crucial part of understanding FRBs and using them for cosmological studies. The first of our FRBs have been published and our first study of our population is currently with the referees. Our first precisely localised FRB and its probable host galaxy is in preparation. We are also pursuing optical follow up of the FRBs that we have been able to localise in images and are preparing associated publications.
We developed machine learning tools to classify transients in real time. Our triggering software enabled us to capture raw telescope data and accurately localise any new transients. We designed and built the pipeline to image these data sets and localise FRBs and transients. We developed a methodology and software to localise transients without the raw data. We also wrote a set of new software (and mathematical description) for removing Radio Frequency Interference. We established a new fast-folding algorithm which greatly enhances the sensitivity to searches for long-period radio pulsars and used it for a number of surveys. All our software is public and we have written associated publications.
We have been able to significantly increase the number of known intermittently radio emitting neutron stars in our galaxy. With our ability to localise them and monitor them this will be a significant contribution to understanding how neutron stars evolve and emit.
We have found a very long period radio emitting neutron star and shown that it was not expected to be radio emitting. It challenges theories on radio emission from neutron stars and links with the magnetars and Fast Radio Bursts. We have also found a couple of other long period radio emitting sources which are starting to form a population.
We have discovered a significant number of FRBs and these have properties, such as their luminosity and redshift which make them an important contribution to our understanding of the overall population of FRBs.
We have been able to localise a number of FRBs and determine the nature of their host galaxies, adding important input for determining the origin, or origins of FRBs.
We found that one of the well known repeating FRBs has an activity period, i.e. where it bursts, of 160 days, which challenges ideas about what is the origin of these systems and of their emission.
We performed simulation work that provided important input on the question of whether all FRBs are repeating sources or not and also how many FRBs we need to study the cosmological event of Helium reionisation.
We developed new and improved algorithms and the associated (freely available) software to: localise transient sources in beamformed data (SeeKAT), remove radio frequency RFI (IQRM), identify radio transients using machine learning (FRBID), identify optical transients from other events (MeerCRAB) and a Fast Folding Algorithm for finding pulsars (riptide).
We have found a very long period radio emitting neutron star and shown that it was not expected to be radio emitting. It challenges theories on radio emission from neutron stars and links with the magnetars and Fast Radio Bursts. We have also found a couple of other long period radio emitting sources which are starting to form a population.
We have discovered a significant number of FRBs and these have properties, such as their luminosity and redshift which make them an important contribution to our understanding of the overall population of FRBs.
We have been able to localise a number of FRBs and determine the nature of their host galaxies, adding important input for determining the origin, or origins of FRBs.
We found that one of the well known repeating FRBs has an activity period, i.e. where it bursts, of 160 days, which challenges ideas about what is the origin of these systems and of their emission.
We performed simulation work that provided important input on the question of whether all FRBs are repeating sources or not and also how many FRBs we need to study the cosmological event of Helium reionisation.
We developed new and improved algorithms and the associated (freely available) software to: localise transient sources in beamformed data (SeeKAT), remove radio frequency RFI (IQRM), identify radio transients using machine learning (FRBID), identify optical transients from other events (MeerCRAB) and a Fast Folding Algorithm for finding pulsars (riptide).