RAiSE HD: Lagrangian particle based model for extended AGNs at radio and X-ray wavelengths
Dr. Ross Turner
Radio-frequency surveys using new generation telescopes are providing observations of millions of previously undiscovered galaxies by probing ever deeper into the universe. However, at most a few percent of active galactic nuclei (AGNs) that will be detected in these surveys will have optical spectroscopy or photometry. Turner & Shabala (2019) showed the distance to nearby AGNs can be accurately measured using only radio-frequency observations by making use of the Radio AGNs in Semi-analytic Environments (RAiSE) astrophysical fluid dynamics model (Turner & Shabala 2015). Turner et al. (2020b) used this new approach to constrain the distances for a modest sample of 15 AGNs up to 11.9 million light-years away and found excellent agreement (<10% error) with spectroscopic redshifts. However, the existing RAiSE code will (in a few months) be superseded by a Lagrangian particle based analytic model that considers the evolutionary histories of individual packets of synchrotron-emitting electrons. With the extra precision of the new model, the measured distances to AGNs with known spectroscopic redshifts can instead be used to constrain cosmological constants; with good coverage to high redshifts (z > 5) this method may help resolve the current tension in Hubble constant measurements. This research may also benefit from X-ray observations to find candidate high-redshift extended AGNs. Turner et al. (2020a) previously found a factor of ten more remnants can be detected using X-ray wavelengths over radio frequencies at z > 2.2, increasing to a factor of 100 for redshifts z > 3.1.
Location: Online
https://cesnet.zoom.us/j/91257675260?pwd=M1FxNkNqcEszRU5SSVpZbFpLMm9rZz09 Passcode: 232356 Meeting ID: 912 5767 5260