Studies of the kilo-parsec scale radio and optical emission from X-ray jets in active galactic nuclei
Abstract
This dissertation is composed of three main contributions to the study of jets in Active Galactic Nuclei (AGN). Several new cases of optical-emitting AGN jets and hotspots were discovered by searching through archival Hubble Space Telescope data. Utilizing multi-frequency radio data, the optical emission is attributed to synchrotron radiation from very high energy electrons (Lorentz factors of ∼105 ). The dependence of the estimated synchrotron break frequency and magnetic field of the hotspots fit the expected behavior from simple shock acceleration theory. A search for radio counterparts of the proposed X-ray jets in two high-redshift quasars yielded the radio detection of a jet in the z = 4.3 quasar GB 1508+5714, and a strong upper limit in the z = 5.99 quasar SDSS 1306+0356. The high X-ray to radio monochromatic luminosity ratio of the GB 1508+5714 jet, in comparison to known cases at lower redshift, support the interpretation of the X-rays as inverse Compton scattered emission off the CMB by electrons in the jet emitting radiation at lower (radio) frequencies. Multi-band radio (VLA and MERLIN) imaging and polarimetry observations of a sample of 17 bright AGN jets are presented. These radio jets were targeted in a joint Chandra X-ray Observatory and Hubble Space Telescope survey program aimed at detecting their X-ray and optical counterparts. The data allowed us to identify X- ray/optical emission associated with the radio jets, to determine the emission mechanism responsible for the higher energy emission, and the combined multi-wavelength data allowed us to set some unique constraints on the physics of these jets.
- Publication:
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Ph.D. Thesis
- Pub Date:
- September 2004
- Bibcode:
- 2004PhDT........11C
- Keywords:
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- Physics: Astronomy and Astrophysics