Thesis Topic: Multi-wavelength studies of blazars


Thesis Supervisors: Paolo Padovani




Blazars are a class of Active Galactic Nuclei (AGN) distinguished by the fact that their non-thermal, strongly anisotropic emission is believed to be coming from material moving at relativistic speed pointing in our direction. Once considered rare sources, blazars are now being detected in increasingly large numbers at mm and gamma-ray energies by the Wilkinson Microwave Anisotropy Probe(WMAP), the Planck, and Fermi satellites. Faint blazars are also being detected as serendipitous sources in SWIFT-XRT(X-ray) images and the recently released WISE (near-IR) data promise to be extremely interesting for blazar studies as well.

Studies of blazars allow astronomers to touch upon a variety of topics, including the disk - jet relationship in AGN, jet physics, AGN feedback, radio source evolution, etc. In partnership with Paolo Giommi, who's director of the ASI Science Data Center (ASDC) located at ESRIN, in Frascati, Italy, and is heavily involved with the SWIFT, Planck, and Fermi missions, I am proposing a range of thesis topics, including:

  • blazar survey WISE-based (the largest blazar sample ever):
    • efficiency optimization
    • optical identifications
    • spectral energy distribution (SED) characterization
    • sample building and cleaning
    • astrophysical results (e.g., number counts, luminosity functions, evolution, thermal/non-thermal ratio)
  • blazar contribution to the hard X-ray/gamma-ray/micro-wave backgrounds:
    • blazar SED characterization: how different types contribute in the hard X-ray and gamma-ray bands
    • Planck sources and the micro-wave background
  • blazar studies in the time domain: correlations between light curves in different bands
  • unified schemes at low fluxes/powers: blazar/radio-galaxy transition
  • AGN/host galaxy relationship
  • All of the above are truly multi-wavelength studies, which will use radio, WMAP, Planck, Sloan, XMM, SWIFT, Rosat, Fermi, (and more) catalogues and data. Follow-up and/or optical identification observations with ESO telescope will also be needed. The thesis can be tailored to the student's preference and skills.

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