Feedback from growing central supermassive black holes, also known as active galactic nuclei (AGN), is considered a part of the life cycle of most galaxies, linking the black hole mass and star formation. Two modes of AGN feedback can come into play: (1) quasar or radiative mode; and (2) radio or kinetic mode. Examining the connection between the radio AGN with the host galaxy and the circumgalactic medium connects the two modes of AGN feedback with the environment. The citizen science project, Radio Galaxy Zoo (RGZ) has identified some green galaxies in SDSS that may be associated with double radio sources AGNs (DRAGNs). The green optical appearance of these galaxies originate from the strong OIII emission line and can be indicators of intense star formation occurring within the host galaxy. If these green galaxies host AGN, then we have a set of galaxies in a certain phase of formation as we believe that AGN can suppress star formation, tying into the whole debate of how black holes and galaxies co-evolve.
The specific aims for this project are:
1. Process the follow-up radio continuum observations from the Jansky Very Large Array (JVLA) in New Mexico in order to study the radio galaxies that are actively growing their central supermassive black holes. We also have spectroscopic/IFS follow-up observations as well as HST imaging for a few of these galaxies.
2. Connect the radio AGN phase with the source of ionisation in the host galaxy in order to determine the type of ‘feedback’ that growing supermassive black holes have on the interstellar medium and circumgalactic medium of their host galaxies.
3. Compare the evolutionary phase of these green DRAGNs to other types of green classes of galaxies such as the “voorwerpjes”, the “green peas” or the “green beans”. Determine the implication that this class of object has on how galaxies grow their central supermassive black holes and evolve.
Candidate green DRAGN that may also be the host of a Hybrid Morphology Radio Source (HyMoRS; Kapinska et al 2017).
Professor Lister Staveley-Smith
Director, Science (UWA)Read More