DRAO Seminar Series Fall 2019


Time & Date Speaker Title
14:00 Thu Oct 10 Scott Tilley Optical and Radio based satellite tracking using astrometrical position and Doppler analysis to determine orbital elements and spacecraft characteristics.
14:00 Thu Oct 10 Ryan Shannon
Swinburne
Finding and localizing fast radio bursts with ASKAP
14:00 Thu Oct 10 Katia Moskvitch
WIRED, UK
Science Journalism: Errors = Media x Confusion^2
14:00 Wed Nov 06 Doris Arzoumanian
Institute of Astrophysics and Space Sciences, Porto
Understanding the Observed Properties of Interstellar Filaments

Finding and localizing fast radio bursts with ASKAP

Ryan Shannon (Swinburne)

Enabled by new wide-field facilities, rapid progress is being made in understanding fast radio bursts (FRBs). These bright millisecond flashes of radio emission and cosmological distances imply an unusual and extremely energetic emission mechanism. As the bursts show the imprint of passage through all ionized plasma long their lines of sight, they also promise to be a valuable probe of the intergalactic medium. Key to understanding both is the direct localization of a sample of bursts to arcsecond precision. In this talk, I will present the results of searches for fast radio bursts with the Australian Square Kilometre Array Pathfinder (ASKAP). I will review the fast-transient search systems employed on the telescope, which are capable of localizing fast radio bursts to 100 milliarcsecond precision. I will present the results of the multi-wavelength follow-up campaigns to identify FRB host galaxies and characterize FRB emission. I will conclude with the implications of the hosts and distances for both understanding burst progenitors and their use as a probe of the intergalactic medium.

Optical and Radio based satellite tracking using astrometrical position and Doppler analysis to determine orbital elements and spacecraft characteristics.

Scott Tilley

Details will be provided of a tracking system designed to obtain both optical and radio based astrometrical and radio based Doppler characteristics of spacecraft in low Earth orbit (LEO), high Earth orbit (HEO), Geosynchronous Earth orbit (GEO) and missions around and in the vicinity of the Moon. The system consists of multiple S-band antennas mounted coaxially with various optical sensors allowing for detection and tracking of objects optically and by radio simultaneously. Radio is used primarily to enable visual tracking of targets by refining their trajectories until such time as they are constrained enough to allow for visual acquisition. Using visual acquisition the station in concert with other observers can constrain orbital details to allow for reliable tracking and orbital element generation for categorization. A description of the hardware and software used will be provided along with the operational techniques that allowed for the recovery of IMAGE [2000-13A, 26113] as well as various other missions.

Science Journalism: Errors = Media x Confusion^2

Katia Moskvitch (WIRED UK)

Whenever there is a story in the media that gets a researcher’s paper horribly wrong, scientists are quick to blame the journalist. And it’s true that journalists make mistakes: science is hard, and even a science journalist won’t be an expert in all areas of science, let alone a regular reporter who covers politics today, sports tomorrow and science on the weekend. But when your research is misinterpreted all over the internet, it’s not good for your reputation – and just as bad for the reputation of the journalist; believe it or not, most journalists actually do care about getting facts right. Some mistakes are due to press offices overhyping the research, some – to journalists not checking their facts properly, and some – to the scientists themselves who fail to work with the media in the right way. So how can we all work together to improve the quality of science journalism? Because at the end of the day, it’s not just about the scientists and the media, but also about the public that often gets terribly misinformed. And it’s not that difficult to make it better. This talk, hopefully, will lead to a lively discussion, so that collaboratively we can find ways of improving the quality of science journalism.

Understanding the Observed Properties of Interstellar Filaments

Doris Arzoumanian (IA Porto)

The highly filamentary structure of the interstellar medium is impressively revealed by the unprecedented quality and sky coverage of Herschel and Planck images tracing the Galactic cold dust emission. These observations provide the required data to describe in detail the properties of the filamentary structures observed in both quiescent clouds and in star forming regions, where the densest filaments appear to be the main sites of star formation. The omnipresence of filaments in observations as well as in numerical simulations suggests that the formation of filamentary structures is a natural product of the interplay between interstellar shock waves, gravity, and magnetic fields. The detailed description of their observed properties is important to improve our understanding of their formation and evolution.

I will present what we have learned about the properties of the filamentary structures derived from dust continuum data in total and polarized intensity and molecular line observations, and I will discuss the observational constraints on the formation and evolution of molecular filaments, and their role in the star formation process.