The goal was to test the orientation-only model of AGN unification from a cosmological perspective, by modelling the halo occupation of SDSS + WISE selected obscured and unobscured quasars, using their clustering data (top and bottom panels). We found no statistically significant evidence for a halo mass dependence, but there was a hint of obscured quasars residing in more massive haloes.

We predicted that with additional or improved data in future one could potentially find higher masses and higher satellite fraction for obscured quasars.

Later, Grayson C. Petter, et al. (2023), using the clustering data but also including quasar position-CMB lensing cross-correlation measurements, conclusively proved one of our predictions: that obscured quasars indeed reside in higher mass haloes. However, they did not conclude a significant difference in satellite fraction. Still, it is key evidence in favour of an evolutionary model of obscured and unobscured quasars, as opposed to the orientation-only hypothesis.

I developed a model for relativistically beamed jets of blazars in a multi-zone leptonic model. It simulates multiple shock-fronts travelling down the jet, energizing the electrons, which subsequently cool via Synchrotron and Inverse Compton (IC) processes. The Inverse Compton up-scatters photons from disk and torus, called External Compton (EC), and the synchrotron photons produced in the jet, called Synchrotron Self-Compton (SSC).

As a key improvement compared to previous work, I included up-scattering in such a way that the SSC in each "cell" of the jet up-scatters synchrotron photons from all other cells in the multi-zone jet, while properly accounting for correct photon travel-time delays.

This was crucial to generate realistic features of blazar light-curves, across all energies: radio to gamma rays. The jet simulation code produces realistic blazar spectral energy distribution (SED), as shown in the second panel with the classic 2-hump SED.

The key aspect of the code was generating light-curves with realistic blazar variability power-spectrum, realistic flaring time delays between different wavelengths, and the existence of "orphan flares". The third and fourth panels show infrared and X-ray lightcurves for reasonable simulation parameters.

We have used this jet simulation code across multiple projects to probe and explain observed features of blazar jets. For example the last panel shows simulated RMS-flux relation, an interesting feature of observed blazar variability. The relation just demonstrates the observed fact that blazars in high flaring states (increased flux) also demonstrates higher fluctuation in their emission (increased root-mean square or RMS of their variability). My jet simulation code naturally predicts this observed trend, and we can predict how the trend changes for different wavelengths and for different jet simulation paramaters.