• "Eta-Catarina-Nebula"

Paul Ray Burd

Email: paul.r.burd@astro.uni-wuerzburg.de

Phone: +49931/3188711

I am interested in studying active galactic nuclei (AGN), particularly Blazars, where the emission is dominated by relativistic Doppler beaming due to small inclination angles. I utilize data products from different observation methods to analyze the smallest resolvable (pc) scales as well as the largest (kpc-Mpc) scales in a morphological, kinematic and spectral sense. Furthermore, my studies involve time-domain analysis of these sources.

Blazars on pc-scales:

I utilize VLBI data to analyze the innermost observable jets of AGN to study the jet geometry (transitions therein), magnetic fields and brightness temperature. Such parameter studies aim to understand the scaling of these parameters within a jet and also may be used to learn about the launching mechanism of jets (Blandford-Znajek mechanism).

Blazars on kpc-scales:

Data from telescopes like the VLA, GMRT, and LOFAR are used to study blazars on kpc-scales. At low radio frequencies (MHz - low GHz regime) the unbeamed emission of the extended structures becomes optically thin and the radio spectrum of these sources steepens in contrast to the core dominated flat spectrum in the higher GHz regime. Different properties of these objects on kpc-scales like morphology and luminosity can be studied to test the unification scheme of AGN. Also, an understanding of the scaling behavior of quantities like the diameter of a jet (and possible breaks of such parameters) from pc to kpc scales can help to understand the resulting morphologies of AGN on large scales.

Time series data from AGN:

Autoregressive (AR) processes are known to mimic several phenomena in physics (e.g. Brownian motion, the noise pattern of currents in wires and also light curves from AGN in different energy bands and on different time scales). Thereby, known physical properties (e.g. power density spectra which define the color of correlated noise, flux distribution, and rise- and decay times) can be produced. I study the possibility to simulate light curves (LCs) of AGN (e.g. gamma lightcurves from Fermi/LAT) with simple AR processes. A special focus lies on the Ornstein-Uhlenbeck (OU) process, and how to map parameters, obtained from measured LCs to the parameters relevant in the OU process, which in turn produce synthetic LCs. 

  • 2014-2017: teaching assistant and tutorials for classical mechanics and electrodynamics
  • 2016: teaching assistant for a basic lab course
  • 2015-current: teaching assistant for the VLBI lab course
  • 2016-current: teaching assistant for Introduction to astronomy and Astrophysics

  • 2011: Abitur at Schiller Gymnasium Hof
  • 2014: Bachelor of Science at university of Würzburg
  • 2017: Master of Science at university of Würzburg
  • 2017: Radio Astronomy School at the National Centre for Radio Astrophysics, Pune, India
  • 2017 - current: PhD student at the university of Würzburg