Rujuta Purohit

I am a graduate student in Astronomy at Boston University. My research interests are in galaxy and black hole co-evolution, intermediate-mass black holes, AGN population statistics, and large-scale structure of the Universe.

I graduated from Dartmouth College in 2024 where I majored in Physics and Astronomy. I worked on intermediate-mass black holes with Professor Ryan Hickox.

My CV can be found here. Some highlights of my projects are listed below.

(Mature Manuscript) Lowest-mass X-ray selected AGNs in the Bootes Field

We present a multi-wavelength analysis of three candidate active galactic nuclei (AGNs) in low-mass galaxies in the Bootes field with the aim of improving constraints on the occupation fraction of low-mass black holes (BHs). Galaxies with low stellar masses are particularly interesting hosts for AGNs as they may contain BHs that have not grown significantly since the epoch of their formation in the early Universe. Using archival data from the Chandra X-ray Observatory, we find three X-ray luminous low-mass galaxies and assess whether they host AGNs. We find one of these sources to be variable in the X-ray and compute its X-ray light curve and spectrum.

Binary black hole mergers in dense star clusters with gravitational runaway

One of the proposed mechanisms for IMBH formation is a collisional runaway process in dense young star clusters. This seed IMBH could then grow further through binary mergers with other stellar-mass BHs. Here we investigate the gravitational-wave (GW) signals produced during these later IMBH--BH mergers. We use a state-of-the-art semi-analytic approach to study the stellar dynamics and to characterize the rates and properties of IMBH--BH mergers. We also study the prospects for detection of these mergers by current and future GW observatories. DOI

Galaxy Cluster Environments of Bent, Double-Lobed Radio Sources as Seen in the X-ray with eROSITA

Bent, double-lobed radio sources driven by active galactic nuclei (AGN) are usually associated with clusters of galaxies but are sometimes found in less rich environments. This raises the question of how their environments impact their formation and evolution. We correlate a large sample of bent, double-lobed radio sources over a wide range of redshifts with X-ray data from eROSITA. In particular, we match the radio sources with the eROSITA galaxy cluster catalog of Bulbul et al. 2024 to examine their surroundings. We calculate the physical offset between the radio sources and the cluster centers found from the X-ray. Studying these bent radio sources is important to understanding the formation and evolution of galaxies across cosmic time.