My research focuses on the formation and early evolution of stars, particularly the interaction between jets, circumstellar disks, and their surrounding environments. I use multi-wavelength data from JWST and ALMA to study a diverse population of protostars from deeply embedded Class 0 systems to more evolved Class II sources like T Tauri and Herbig Ae/Be stars. My goal is to understand how these systems evolve over time, how their structures differ across environments, and how accretion and outflow are linked to the formation of the stars and planets.
My thesis centers on studying protostellar outflows, circumstellar disks, and their envelopes during the earliest stages of star formation. By combining JWST and ALMA observations, I am examining a broad sample of young stellar objects to understand how jets evolve across Class 0–II systems and how these processes regulate angular momentum, accretion, and chemical enrichment. A key advantage of JWST is its ability to provide both spectral and spatial information simultaneously, revealing nested outflow structures traced by molecular lines (e.g., H₂, CO) and atomic fine-structure lines (e.g., [Fe II], [Ni II]). Using these diagnostics, I aim to connect excitation conditions, whether driven by irradiation, shocks or cosmic rays with the dynamics of mass loss and disk evolution.
One of the protostars I’ve been especially interested in is TMC1A, a Class I object with a bipolar jet embedded within a large-scale envelope. Thanks to the incredible sensitivity of JWST, the jet was detected through the dense envelope for the first time (Harsono et al. 2023). We later found that the jet was bipolar and asymmetric, with one side more prominently visible (Assani et al. 2024). In a follow-up study, we modeled the jet's intrinsic emission based on these observations. By comparing the predicted and observed spectra, we inferred the wavelength-dependent opacity of the envelope (Assani et al. 2025). The goal for this is to learn about the composition and size distribution of dust grains in the surrounding material that feeds the accretion disk where planets will grow and ultimately the forming star. Our study showed that mid-infrared attenuation towards protostars might be larger than predicted by typical background star-light studies of dark clouds. This suggests that dust grains undergo substantial growth between dark clouds and dense protostellar environments, providing new evidence for the long-standing puzzle of how micron-sized particles eventually become planets.
To follow up, I am leading a program as Principal Investigator of JWST GO 8872, “The Dark Side of the Force: Unraveling Protostellar Jet Asymmetry by Probing TMC1A’s Fainter Red-shifted Outflow with JWST.” In this project, we aim to map the southern, redshifted lobe of the outflow in greater detail, exploring why many protostellar jets appear asymmetric. This asymmetry may result from geometric or environmental factors, such as increased obscuration along one line of sight, or from intrinsic differences in the launching mechanisms themselves. The proposal was one of the few accepted in JWST’s highly competitive Cycle 3, where only about 11% of proposals were selected out of more than 75,000 requested hours. Access to such a powerful and sensitive instrument is rare, and this project represents a unique opportunity to push our understanding of outflow physics!
In parallel, I continue my long-standing collaboration with Dr. Mike Sitko, Professor Emeritus at the University of Cincinnati. Together, we study Class II and Herbig Ae/Be stars using the SpeX spectrometer on the NASA Infrared Telescope Facility (IRTF) to explore how accretion evolves in these systems. Our work has focused on infrared variability and disk evolution, focusing especially on accretion signatures traced by hydrogen lines (Paβ, Brγ, and Brα). These emission lines offer a window into how accretion changes over time as the protostar transitions toward becoming a full-fledged star—where hydrogen fusion begins but still remains surrounded by a circumstellar disk. Unlike the more embedded Class 0/I sources, these systems represent a more evolved phase of star formation, where accretion is less intense but still critical to shaping stellar and disk properties.
Earlier in my graduate training, I also pursued theoretical work related to planet formation, where I used 3D radiation hydrodynamics simulations on supercomputers to model how rocky planets form in disk environments. That experience helped grow my interest in how stars and planets form together and gave me a strong foundation in computational astrophysics and large exa-scale high-performance computing.
Overall, my research combines observational and computational techniques to explore the processes that govern how stars and planets take shape, evolve, and interact with the environments they form in. The era of JWST and ALMA is opening up remarkable new ways to answer these questions, and I’m excited to be part of it.
I have not included future publications in the lists below. To show activity in research, but refrain from sharing unpublished and competitive work, I will note the following:
- Lead Author: 2 Ongoing Papers focused on multi-source outflow analysis and cosmic ray rates in disk regions (to be submitted).
- Co-Authorships: 3 Papers for variability/inner disk structure around herbig Ae/Be & T Tauri Stars (to be submitted). 2 Papers focused on Outflows with JOYS+ collaboration (to be submitted). 1 Letter on PAH and scattered light structure (submitted)
A total of ~8 papers should be published within next year.
For more details, visit my Google Scholar profile.