Thesis

The First Radio Galaxies in the Universe

Details

  • Call:

    IDPASC Portugal - PHD Programme 2015

  • Academic Year:

    2015 / 2016

  • Domains:

    Cosmology | Astrophysics

  • Supervisor:

    José Afonso

  • Co-Supervisor:

    Mario Santos

  • Institution:

    Faculdade de Ciências - Universidade de Lisboa

  • Host Institution:

    Faculdade de Ciências - Universidade de Lisboa

  • Abstract:

    Recent observations of the highest redshift quasars and radio galaxies pinpoint the early growth of supermassive black holes (SMBH) that trigger the formation of active galactic nuclei (AGNs) at redshifts greater than 7. It is anticipated that radio emission can be detected from such early AGN, although its characteristics are still quite undeterminated. The importance of such detection, however, is extremely high. It will: (a) provide us with a lighthouse that reveals the physics of the first accretion episodes to the first SMBHs in the Universe; (b) allow the direct study of the neutral gas throughout the Epoch of Reionisation itself with the next generation of radio telescopes, through the observation and study of the HI 21cm forest against such early AGN; (c) allow us to trace the early growth of Large Scale Structure in the Universe. After decades of laborious work, trying to understand the deepest radio observations, the conditions are now finally right to develop a project that can make us understand where are the “first radio galaxies” and how to find them with upcoming radio telescopes. In this thesis, the student will understand the current knowledge about powerful radio sources and their evolution out to the very highest currently observable redshifts (z~5-6). He will assemble different models of structure formation that handle the formation and evolution of the first SMBH in the Universe and confront theory and observations. With this process, he will aim to (a) identify flaws and difficulties in the models of structure formation, pinpointing improvements needed in the light of the deepest radio observations; (b) predict the properties and observable characteristics of the first radio-bright SMBHs, with the particular objective of improving the SKA development (frequency coverage, sensitivity and resolution, for example) towards the detections of this first generation of radio galaxies. Implications for the upcoming generation of deep radio surveys like EMU and WODAN will be also considered within this thesis.