I'm a fourth-year physics PhD student at MIT. I am fortunate to be advised by Erin Kara and work closely with Kevin Burdge and Riccardo Arcodia.
I was an undergrad at Columbia, where I worked with Frits Paerels on X-ray astronomy and David Kipping on extrasolar planets, graduating in 2022. Before that, I grew up in Edison, New Jersey.
e-mail: joheen(at)mit(dot)edu
Research Interests:
My research is in high-energy astrophysics, which provides a remarkable diversity of mysterious and exciting phenomena to explore. I study compact objects (e.g. black holes, white dwarfs) using data primarily from X-ray telescopes (e.g. NICER, XMM-Newton) and ideas/models from plasma physics, atomic physics, relativity, and radiative transfer. The overarching goal of this work is to understand how compact objects and binaries form, evolve, influence their surroundings, and produce electromagnetic and gravitational radiation to power some of the most energetic phenomena in nature. A mostly accidental theme of my current work is electromagnetic emission from low-frequency (~μHz-mHz) gravitational wave sources, and I am excited by their potential for multi-messenger astrophysics. Some topics I work on are:
-Quasi-Periodic Eruptions (QPEs), a newly discovered type of recurring X-ray transient which may be the first-known electromagnetic counterparts to EMRIs. An enticing possibility is using QPE timings to map general relativistic precession effects within ~hundred gravitational radii of supermassive black holes (see e.g. the effects of frame-dragging and apsidal precession). My hope is that QPEs will enable new direct measurements of orbital dynamics in galaxy nuclei, and teach us something about supermassive black holes in the process.
-Ultracompact binaries, which are the dominant millihertz gravitational wave sources for upcoming space-based gravitational wave detectors. I study their orbital evolution as a probe of angular momentum transport during mass-transfer, and am curious what we may learn from multi-messenger study of their accretion disks.
-Tidal Disruption Events, which provide a unique laboratory to study the formation and evolution of turbulent accretion flows around supermassive black holes.
-X-ray astronomy, high performance computing, large-scale data analysis, Bayesian inference.
Selected publications:
My first-/second-author papers are listed below. You can find all of my papers on ADS, arXiv, or Google Scholar.
Prospects for EMRI/MBH parameter estimation using Quasi-Periodic Eruption timings: short-timescale analysis
Joheen Chakraborty*, Lisa Drummond*, Matteo Bonetti, Alessia Franchini, Shubham Kejriwal, et al. (*equal contribution)
Accepted to The Astrophysical Journal
[Paper]
[Code]
Rapidly varying ionization features in a Quasi-periodic Eruption: a homologous expansion model for the spectroscopic evolution
Joheen Chakraborty, Peter Kosec, Erin Kara, Giovanni Miniutti, et al.
Astrophysical Journal, May 2025
[Paper]
[Press]
[Summary]
Discovery of extreme Quasi-Periodic Eruptions in a newly accreting massive black hole
Lorena Hernández-García, Joheen Chakraborty, Paula Sánchez-Sáez, Claudi Ricci, et al.
Nature Astronomy, Apr. 2025
[Paper]
[Press]
[Summary]
Discovery of Quasi-periodic Eruptions in the Tidal Disruption Event and Extreme Coronal Line Emitter AT2022upj: implications for the QPE/TDE fraction and a connection to ECLEs
Joheen Chakraborty, Erin Kara, Riccardo Arcodia, Johannes Buchner, et al.
Astrophysical Journal Letters, Apr. 2025
[Paper]
[Summary]
Expanding the ultracompacts: gravitational wave-driven mass transfer in the shortest-period binaries with accretion disks
Joheen Chakraborty, Kevin Burdge, Saul Rappaport, James Munday, et al.
Astrophysical Journal, Dec. 2024
[Paper]
Testing EMRI models for Quasi-periodic Eruptions with 3.5 years of monitoring eRO-QPE1
Joheen Chakraborty, Riccardo Arcodia, Erin Kara, Giovanni Miniutti, Margherita Giustini, et al.
Astrophysical Journal, Apr. 2024
[Paper]
[Summary]
[Talk]
Transit duration and timing variations from binary planets
Joheen Chakraborty, David Kipping
Astrophysical Journal, Feb. 2023
[Paper]
Possible X-ray Quasi-periodic Eruptions in a tidal disruption event candidate
Joheen Chakraborty, Erin Kara, Megan Masterson, Margherita Giustini, Giovanni Miniutti, Richard Saxton
Astrophysical Journal Letters, Nov. 2021
[Paper]
[Press]
[Talk]
Hundreds of new periodic signals detected in the first year of TESS with the weirddetector
Joheen Chakraborty, Adam Wheeler, David Kipping
Astrophysical Journal, Dec. 2020
[Paper]
