I am interested about understanding galaxy formation and evolution. With recent developments in technology and telescopes spanning over complete spectrum of light deep into the sky, we have been able to take significant strides towards a detailed picture of evolution of the galaxies. It is well known that most of the observed galaxies harbour supermassive black holes (SMBH.) Most of these SMBH's have an active core and are called active galactic nuclei (AGN.) AGNs affect the evolution of galaxy via complex sets of processes called feedback both positively and negatively.
Under the supervision of Prof. Ravi Joshi, we are studying the impact of AGN on the galaxy in a spatially resolved manner. We have developed an end-to-end pipeline to determine the physical properties and complete spectrum of a galaxy using multiwavelength data available. By taking advantage of optical observations from Subaru 8-m telescope, PANNSTARS and SDSS, we have developed a novel technique to determine the emission line flux maps of any galaxy. Subsequently, we bin the galaxy and fit the SED of the galaxy in order to determine various physical parameters such as star formation rate, stellar mass, etc to directly understand the impact of the outflows/jets on the galaxy and its evolution.
Understanding the earliest galaxies formed in the Universe within a billion years of the Big Bang poses a significant challenge in cosmology, as these galaxies are pivotal in the cosmic phase transition known as Cosmic Reionization and in enriching the intergalactic medium with heavy elements. Recent technological advancements, notably with instruments like the JWST and ALMA interferometer, have allowed us to delve deeper into space and scrutinize these early galaxies with unprecedented detail. Observations from JWST have pushed our sight beyond z > 10, while ALMA has offered insights into galaxies beyond z > 7. However, these observations have unveiled exceptionally bright sources at z > 10, which challenge the prevailing ΛCDM model of large-scale structure formation, prompting inquiries into the rapid mass accumulation of these galaxies shortly after the Big Bang.
Recent research has led towards explaining these conflicting observations. Dust has an important role in figuring out the evolution of above galaxies. During my MS Thesis, I worked under the supervision of Prof. Andrea Ferrara (SNS Pisa) to determine the relationship between dust obscuration and star formation rate of the galaxies. Subsequently, it allowed us to explain the overabundance of such sources as observed by JWST. However, there has been recent developments via ALMA REBELS observations. On follow up to these galaxies, no dust signature was obtained to explain the potential dust obscuration. This poses further thorny questions such as where did the dust produced go - was it blown away by AGN feedback? I am interested in figuring out the evolution of dust and metal which could potential help us understand the process of galaxy evolution.
During my thesis, we also observed that the theoretical infrared luminosity function (IR LF calculated in thesis) does not coincide with the observed one. Further questions arose from such an observation. There could be multiple potential explanations to the above questions namedly a. multiphase distribution of dust disallowing the detection of these galaxies b. such galaxies are completely obscured by dust. For able to answer the question, we determined the number density of the galaxies using a simple theoretical model which needs to be tested with upcoming blind, deep surveys.