My (virtual) ESO Summer Research Programme

Early last year I was selected to attend ESO’s 2020 Summer Research Programme, which is an opportunity for university students who are not yet enrolled in a PhD programme and are interested in astronomy to obtain research experience alongside astronomers based at ESO Headquarters (HQ) in Garching, Germany. While the pandemic meant that the programme could not to be held in-person, I was lucky enough to get to complete my research project remotely in the Australian summer, and have a fantastic experience working online with researchers at ESO.

The aim of my project was to investigate the properties of the interstellar medium of a galaxy that hosts a highly luminous quasar (the quasar is 3C 273, the first quasar ever to be identified!). In particular, the project involved imaging ALMA calibration data from the ALMACAL survey, which compiles data that is essentially collected for free during science observations. Through analysis of Carbon Monoxide (CO) line emission data from various ALMA calibration observations, we discovered an unusually shaped rotating disk of molecular gas in the host galaxy of 3C 273. We were also able to detect that the gas closer to the central regions of the galaxy was more excited than the gas at the outskirts (see left figure below). This could indicate that some physical process is heating the inner regions of the CO disk, which led us to check whether this excitation could be due to physical proximity to the radio jet. Through a combination of our ALMACAL images and VLA data (which allowed us to plot the radio jets associated with 3C 273) we saw that it seems likely that the radio jets are interacting with the disk of molecular gas, causing gas excitation! (right figure below)