from 28 June 2015 to 3 July 2015 (Africa/Johannesburg)
Africa/Johannesburg timezone
SAIP2015 Proceeding published on 17 July 2016
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Optical spectroscopic observations of unclassified Active Galactic Nuclei in the Fermi-2LAC catalogue

Presented by Ms. Lizelke KLINDT on 3 Jul 2015 from 11:50 to 12:10
Type: Oral Presentation
Session: Astro
Track: Track D1 - Astrophysics


Blazars constitute the most violent astronomical objects with relativistic jets emitting radiation at all frequencies. The 2nd Fermi-LAT catalogue of AGN contains 157 sources which are classified as unknown type. All sources lie at high galactic latitudes (|b| > 10◦) with candidate optical and/or radio counterparts within the Fermi 95% error circle. We are undertaking a multi-wavelength campaign to classify a selected number of these sources which exhibit blazar-like characteristics by establishing their optical spectra, Spectral Energy Distributions and searching for variability. We present preliminary optical spectroscopic observations of 15 of these sources obtained with the SAAO 1.9-m telescope and the Southern African Large Telescope (SALT). The low-resolution spectra are mainly featureless as are expected for BL Lac objects, however Ca II K&H, MgIb and/or NaD absorption lines appear to be present, allowing for a first estimation of the redshift range 0.1 < z < 0.8. The strength of non-thermal jet emission is determined from the depth of the Ca II depression, which is a good indicator whether the targets are potential blazars. Keywords: BL Lacertae objects: general, galaxies: distances and redshifts






Dr. B van Soelen University of the Free State, Department of Physics





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