Speaker
Please indicate whether<br>this abstract may be<br>published online<br>(Yes / No)
Yes
Level for award<br> (Hons, MSc, <br> PhD, N/A)?
MSc
Abstract content <br> (Max 300 words)<br><a href="http://events.saip.org.za/getFile.py/access?resId=0&materialId=0&confId=34" target="_blank">Formatting &<br>Special chars</a>
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
Main supervisor (name and email)<br>and his / her institution
Dr. B van Soelen
vansoelenb@ufs.ac.za
University of the Free State, Department of Physics
Apply to be<br> considered for a student <br> award (Yes / No)?
Yes
Would you like to <br> submit a short paper <br> for the Conference <br> Proceedings (Yes / No)?
Yes
