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Natasha Hurley-Walker - Finding more ultra-long-period transients (ULPMs)
- Natasha's slides can be found here
- Writing Discovery project for funding to do this work
- Building on GLEAM-X J162759.5-523504.3 discovery. This may be the brightest case as is traditional in astronomy discoveries.
- There will be fainter examples
- Differencing visibilities and making images - limited by ionosphere - working on better techniques
- Plan to run Quasi real-time data processing to find targets that are "on", which we would follow up with every instrument and observing mode.
- Theoretical predictions of ULPMs - there should be lots of them but we shouldn't expect to see them as they won't produce radio emission.
- Feasible periods between 10 and 10^4 seconds
- Small amount of DM smearing but not so much at higher frequencies at ~200 MHz for similar durations (20-30s). This means we can get good detection sensitivity without having to do DM trials
- The compromise between sensitivity and FOV is 154 MHz
- Survey design - simulated pulsar distribution - used as this GLEAM source is much further off the plane without an SNR, which is unusual for magnetars.
- 10 pointings - 92% of pulsar population
- Timestep images - adopt IPS techniques
- Less processing than IPS as not interested in such short timescales
- Summer student testing filtering algorithms
- Working on the sensitivity to determine flux density limit that we are sensitive to
- Not sure how much time to apply for - Dwell time of 30 mins per pointing. These pointings also overlap.
- More time means it is less feasible to take observations and reduce these data
- As sources are visible for a few months we only need to do monitoring on a weekly basis.
- Potential for requesting longer dwell times of 60 or 120 mins.
- Not much FTE - could bump up dwell times and requests if on top of data analysis and the MWA time is undersubscribed
- If we actually find a ULP transient then we will drop everything and look at it using all possible observing modes. - Just DDT for VCS and picket fence observations.
- Q Gemma: Think of this as a pilot survey and get pipelines working so 30 mins is fine and justifiable for the initial request.
- Q Joe: Scatter broadening in Galaxy?
- John: It would have to be enormous to dominate over the intrinsic width of the burst
- Natasha: If the pulse is smeared to twice the width then the pulse wont be detectable. If faint even a small bit of scattering will be bad.
- Sensitive to long period transients - sets the dwell time but could pick up medium length timescales (minutes)
- The images could be searched in other dimensions too.
- Many synergies are available for people to work on - contact Natasha!
- We currently have small resources so will try to set things up so people can use the data for other science cases.
- Sensitivity for the extragalactic sky should be 1 mJy but GP will be worse. Would not want to do long extragalactic studies on these fields.
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