DRAO Seminar Series 2023


Time & Date Speaker Title
11:00 Wed Feb 1 Vyacheslav Zakharenko
Institute of Radio Astronomy NAS Ukraine
Remote Talk: A decameter pulsar/transient «blind» survey of the northern sky. Results of transient searching
14:00 Wed Feb 15 Lyla Jung
Australian National University
Remote Talk: Search for magnetized high-velocity clouds using Faraday rotation

Remote Talk: A decameter pulsar/transient «blind» survey of the northern sky. Results of transient searching

Vyacheslav Zakharenko (Institute of Radio Astronomy NAS Ukraine)

This report presents a detailed description of the Decameter pulsar/ transient survey of the northern sky, which was performed using the world’s largest low-frequency radio telescope at decameter wavelengths – UTR-2. This large-scale survey covers the northern sky with an inclination of -10 degrees to +80 degrees, a temporal resolution of 8 ms, and dispersion measure up to 30 pc/cm3.
The main advantage of the decameter range is a wide relative frequency band in which the dispersion delay reaches tens and hundreds of seconds, which allows us to distinguish cosmic pulse signals, and RFI and to determine the dispersion measure with very high accuracy.
380 transients were detected. The conducted tests show that the detected signals cannot be explained by the scintillation of the ionosphere.

Remote Talk: Search for magnetized high-velocity clouds using Faraday rotation

Lyla Jung (Australian National University)

High-velocity clouds (HVCs) around the Milky Way provide direct evidence of ongoing gas accretion that could fuel the future star formation activity of the Galaxy. Theories and numerical simulations predict that the magnetic field significantly affects the efficiency of the mixing at the cloud-halo interface, which could in the long run affect the survival of the clouds. There have been active searches for magnetized HVCs using polarization observations. In this presentation, I will discuss possible obstacles in detecting magnetized HVCs using Faraday rotation and how future polarization surveys will improve the situation. We test the conditions of the detection using the IllustrisTNG50 suite of cosmological simulation. This presentation will provide insight on how to find magnetized HVCs as the first step towards understanding the role of magnetic fields on the evolution of gas clouds around the Galaxy.