Projects
Active Galactic Nuclei (AGN) are energetic astrophysical objects powered by accretion onto supermassive black holes (SMBH) in the center of active galaxies. These powerful sources emit in the full electromagnetic spectrum, and each of the wavelength ranges provides information on the physics of different sub-structures in the AGN such as the relativistic jet (if any), the dusty torus, accretion disk, the corona as well as the environment of the AGN itself.
AGN plays key roles in the formation and evolution of their host galaxies. It can inject significant amounts of energy into its surroundings, through mechanisms such as jet outflows, winds, and radiation pressure. This energy can heat and disperse gas within the galaxy, potentially quenching star formation by preventing the gas from cooling and condensing into new stars. However, under certain conditions, AGN activity can also compress gas clouds, triggering star formation in a process known as “positive feedback.”
During my studies, I developed a method to select high-redshift quasar candidates using custom-made SED fitting code (available on my github) for the 4MOST Chilean AGN/Galaxy Evolution Survey (ChANGES). This resulted in a catalog of around 6,000 high-redshift quasar candidates that 4MOST will observe, with spectroscopic confirmations of some of them already underway.
My second project focuses on quasars with powerful radio jets at z>3.6, using VLT/MUSE data. I have completed the data reduction and analysis, investigating Lyman Alpha Halos and comparing them to those in similar redshift quasars without strong radio jets. We recover 10 new LAHs, suggesting that such extended Lyα emission is more common around RL quasars than around RQ ones at the same redshifts. We have also found that the high-redshift blazars show higher Lyα luminosities and a turbulent nature. We are planning to investigate this further together with Satenik Margaryan, a student from Shanghai Jiao Tong University.
I am involved in the LSST AGN Science Collaboration with Prof. Assef, developing methods to identify AGN photometric properties in future LSST datasets. This project includes creating a training set based on photometric and spectroscopic data from fields such as COSMOS.
Finally, building on the 4MOST/ChANGES candidate selection, I am co-supervising Edgar Harutyunyan (Leipzig University) on the radio characterization and radio SED fitting of the radio-detected high-redshift candidates. Together with the existing IR and optical data, this will produce a multiwavelength SED fit to rank the most promising radio-loud quasar candidates for spectroscopic follow-up, following the recent confirmation of 3 radio-loud quasars at z>5 with Palomar and Gemini North.
More details about each project
Selection of high redshift quasars with SED fitting for 4MOST
Searching for Lya halos around high-redshift radio-loud quasars
Simulating a dataset of AGN with LSST
Characterization and Radio SED fitting of radio-loud high-redshift quasars
