AstroWIT (noun): mental sharpness and inventiveness in astrophysics; keen intelligence.

Postdoctoral Researchers

Dr. Massissilia Hamadouche

Postdoctoral Researcher

Massi (she/her) is an expert in studying the star formation histories, stellar populations, and dynamics of quiescent galaxies at cosmic noon. Here at UMass, she is leading the JWST Deep Dive Project, a Cycle 2 program targeting 11 massive quiescent galaxies at z>3. With this premiere data set, we are reducing and modeling the spectrophotometry in collaboration with PI Francesco Valentino (faculty at the Cosmic Dawn Center in Copenhagen) to constrain the timescales of their rapid star formation, metal enrichment, and quenching.

Professional Webpage: https://massi-hamadouche.carrd.co

Dr. Samantha Berek

NSF Astronomy & Astrophysics postdoctoral Fellow

Sam (she/her) is an expert in globular clusters and dwarf galaxies. Her research focuses on understanding large, clustered star formation in the early universe through both direct high redshift observations and analysis of evolved star clusters in the local universe. At UMass, she is working to expand globular cluster and stellar clump datasets across redshift while developing comprehensive empirical models to link these data into an evolutionary sequence of massive star cluster formation from high redshift stellar clumps to local globular clusters.

Professional Webpage: https://samberek.github.io/samberek/index.html

PhD Students

Sarah Bodansky

PHD Thesis

Sarah (she/her) is a 4th year graduate student working on studying the evolution of dust mass in galaxies out to cosmic noon. Using data from the upcoming Toltec/LMT Ultra Deep Survey, Sarah will help us understand if the lack of evolution in the mean dust obscuration fraction (i.e., the ratio of the obscured star formation rate to total star formation rate in galaxies) with stellar mass and redshift is related to a lack of evolution in their dust masses. Alternatively, it may be that the dust geometry is complex. A careful analysis of this data will have us build a more complete empirical picture. Sarah is also interested in understanding the cold dust properties of quiescent galaxies across cosmic time using the same data set. Sarah completed an Independent Research Project with myself and Prof. Alex Pope working on this same topic. Sarah is also a former Astrobites writer; check out some of her work below!

Astrobites Articles: https://astrobites.org/author/sbodansky/

Aubrey Medrano

PHD Thesis

Aubrey (she/her) is a 3rd year graduate student wrapping up their project together with myself and Prof. Mauro Giavalisco on measuring the spatially resolved properties of galaxies selected from the James Webb Space Telescope PRIMER survey. Aubrey used the Prospector emulator Bayesian framework to fit spatially resolved stellar populations of massive galaxies at cosmic noon based on the PRIMER multi-wavelength photometric data set. She comes with vast experience from her time working within the CEERS collaboration with Prof. Steve Finkelstein, and will continue to develop her working knowledge of data from NASA’s current flagship mission. Aubrey is starting her PhD work in Fall 2025.

Will Jarvis

Independent Research Project

Will (he/him) is a 1st year graduate student working together with myself and Prof. Alexandra Pope on completing a systematic search for globular clusters in early massive quiescent galaxies in the James Webb Space Telescope MINERVA Treasury Program. In the context of the hierarchical merger paradigm, globular cluster populations give us important information to distinguish in-situ formation channels form ex-situ mergers and and accretion. Such an independent measure of the star formation history is invaluable when compared to the properties of the host galaxies, giving us important clues about the formation and assembly of massive galaxies.

Professional Webpage: https://wills-astro.github.io/

Undergraduate Researchers

Ayesha Abdullah*

Jalen Cortes*

Regine Henry*

Kevin Lin*

Easie Ow*

*Member of AstroTROUP

Affiliated Postdoctoral Researchers

Dr. Jacqueline Antwi-Danso

Banting postdoctoral fellow

Jacqueline (she/her) is an expert on the stellar populations and chemical properties of the first massive, quiescent galaxies. Jacqueline is PI of a Cycle 2 JWST program to acquire spectroscopic follow-up of a premier sample of quiescent galaxy candidates at z>3 using JWST/NIRSpec multi-object spectroscopy. She has a full-time position at the University of Toronto through the prestigious Banting Fellowship, spending roughly 25% of her time visiting UMass Amherst, with a joint affiliation.

Professional Webpage: https://antwi-danso.carrd.co/

Other Academic Family Members

** otherwise known as former Astrowhit group members

Postdoctoral Scholars

Dr. Sinclaire Manning (UMass Amherst 2021-2025; NASA Hubble Postdoctoral Fellow) - current Assistant Professor at UMass Amherst
Dr. John Weaver (UMass Amherst 2022-2025; Photometric Catalog lead for the JWST UNCOVER Survey) - current Brinson Prize Postdoctoral Fellow at MIT
Dr. Mimi Song (UMass Amherst 2019-2023; Lead of the 3D-Herschel NASA/ADAP program)

Graduate Students

Aidan Cloonan (UMass Amherst, 2023-2025, Independent Research Project co-advised with Dr. Sinclaire Manning) — current PhD student at UMass
Dr. Sam Cutler (UMass Amherst, 2019-2025, PhD Thesis) — current MINERVA Postdoctoral Research Associate at Tufts
Yanzhe (Jenny) Zhang (UMass Amherst, 2022-2024, Independent Research Project co-advised with Prof. Houjun Mo) — current PhD student at UMass
Joyce Caliendo (UMass Amherst, 2021-2022, Independent Research Project co-advised with Prof. Alex Pope)
Maike Clausen (Exchange student from MPIA, 2021-2022) — current PhD student at the University of Edinburgh
Roxana Popescu (UMass Amherst, 2019-2022, 2nd year project) — current PhD student at UMass
Dr. Mohammad Akhshik (University of Connecticut, 2016-2022, PhD Thesis) — Senior Quantitative Analyst in Finance/Energy at Quant in Baltimore MD
Jonathan Mercedes Feliz (University of Connecticut, 2018-2019) — current Postdoctoral Research Associate at UConn

Undergraduate Students

Seamus McNulty (UMass Spring 2020 - Spring 2024; Honors Thesis; Post-bac Researcher 2024-2026) - currently working in industry
Hope Roundcount (UMass Fall 2023 - Spring 2025) - current UMass Astronomy undergraduate
David Marroquin (UMass Fall 2023 - Spring 2025; AstroTROUP) - Middle School Science Teacher
Zachary Webb (UMass Spring 2020 - Spring 2024; Honors Thesis) - Lab Technician at Spectral Solutions Inc.
Lillian Wright (UMass Fall 2019 - Spring 2023) - current SNU graduate student
Ananya Sreelekha (UMass, Spring 2022-Spring 2023; Honors Independent Project) - UToledo graduate student
Seth Martin (UMass, Spring 2022-Spring 2023; Honors Thesis)
Leonardo Drake (UMass, Spring 2022 - Summer 2022) - UMass Physics masters student
Joyce Caliendo (University of Connecticut, 2018-2021)
Tyler Metivier (University of Connecticut, 2016-2020) — UNH graduate student
Sam Cutler (University of Connecticut, 2016-2019)
Alexandra Cain (University of Connecticut, 2018-2019)
Rochelle Horanzy (University of Connecticut, 2016-2018)
Mohammad Ashas (University of Connecticut, 2016-2018) — science teacher at Fairmont Private Schools, finishing a masters degree at Cal State Long Beach
Warren Sharpp (UMass Amherst/FCAD Internship, June-August 2016)
Daniel Lange-Vagle (Tufts University, 2014 - 2016)
Michael Alburger (NASA/GSFC Summer Internship, June-August 2014)

Aidan Cloonan (who recently completed an independent research project, co-advised with Prof. Manning) submitted a paper to the Astrophysical Journal investigating the UV-to-optical morphologies of “Little Red Dots,” a newly discovered population of compact, very red sources in the early universe. Using PANORAMIC survey data, Aidan identifies two groups of Little Red Dots distinguished by their UV sizes, providing new clues about the relative roles of starlight and active black holes in powering their emission. This work offers fresh insight into the physical nature of these intriguing JWST sources.

*Cloonan, A., Whitaker, K.E., Manning, S., Williams, C., Greene, J., Oesch, P., Weibel, A., Brammer, G., de Graaff, A., Hviding, R., Dayal, P., Jespersen, C., Ji, Z., Labbe, I., Xiao, M., Zhang, Y.,* *A PANORAMIC of UV-optical morphologies of "Little Red Dots": Two groups of LRDs distinguished by UV half-light radius, 2026, arXiv:2603.24700*

Seamus McNulty (a post-baccalaureate researcher and former Honors Thesis undergraduate group member) recently submitted a paper to the Astrophysical Journal introducing 3D-Herschel, a catalog that incorporates far-infrared (FIR) data from Herschel into existing galaxy surveys. The work shows that while basic galaxy properties can often be measured without FIR data, accurately capturing dust emission requires it, and that commonly used infrared conversions depend on stellar mass.

*McNulty, S., Song, M., Whitaker, K.E., Leja, J., Medrano, A., Mathews, E., Dickinson, M., Inami, H., Labbé, I., Marchesini, D., Pope, A., Shivaei, I.,* *3D-Herschel: Constraining Dust Emission with Panchromatic Modeling of 3D-HST Galaxies, 2026, arXiv:2602.22384.*

Massi Hamadouche (current postdoctoral researcher in the group) submitted a paper to the Astrophysical Journal that goes on a deep dive into the physics of the first quenched galaxies. Massi unveils new insights into how massive galaxies in the early universe rapidly formed their stars and shut down star formation on short timescales. The work highlights a diversity of evolutionary pathways and provides new constraints on the processes driving galaxy quenching in the first few billion years of cosmic history.

Hamadouche, M., Whitaker, K.E., Valentino, F., Antwi-Danso, J., Ito, K., Beverage, A., Zhu, P., Brammer, G., Kokorev, V., de Lucia, G., Baker, W., Farcy, M., Gallazzi, A., Gillman, S., Gottumukkala, R., Hirschmann, M., Jespersen, C., Kakimoto, T., Lee, M., Onodera, M., Shimakawa, R., Tanaka, M., Weaver, J., Wu, P.-F., *DeepDive: Tracing the early quenching pathways of massive quiescent galaxies at z>3 from their star-formation histories and chemical abundances, 2026, arXiv:2602.02485.*

Sarah Bodansky (current PhD student in the group) led a paper, now accepted for publication in the Astrophysical Journal, that combines JWST and ALMA imaging to study the morphologies of dusty star-forming galaxies relative to similar mass galaxies. Sarah finds compelling evidence that these galaxies may serve as the missing evolutionary link to the quiescent phase.

Bodansky, S., Whitaker, K.E., Abdullah, A., Lin, J., Oesch, P., Pope, A., Xiao, M., Covelo-Paz, A., Cutler, S., Garcia Diaz, C., Lee, M., Manning, S., Meyer, R., Narayanan, D., Nelson, E., Shivaei, I., van Dokkum, P., *JWST+ALMA reveal the build up of stellar mass in the cores of dusty star-forming galaxies at Cosmic Noon, 2025, arXiv:2507.19472.*

Sam Cutler (group member from 2017–2025) recently published a paper in the Astrophysical Journal exploring the structure and evolution of low-mass quiescent galaxies in dense cluster environments. Using JWST imaging of the Abell 2744 galaxy cluster, Sam finds increased diversity in galaxy sizes compared to similar systems in the field. The results suggest these galaxies quenched at later times and evolved through dynamical interactions, rather than being initially shut down by their environment.

Cutler, S., Weaver, J., Whitaker, K.E., Greene, J., Setton, D., Webb, Z, Abdullah, A., Medrano, A., Bezanson, R., Brammer, G., Feldmann, R., Furtak, L., Glazebrook, K., Labbe, I., Leja, J., Marchesini, D., Miller, T., Mitsuhashi, I., Nanayakkara, T., Nelson, E., Pan, R., Price, S., Suess, K., Wang, B., *The Structure and Formation Histories of Low-mass Quiescent Galaxies in the A2744 Cluster Environment, 2025, ApJ, 993, 169.*

Maike Clausen (group member from 2022-2025) recently published a paper in the Astrophysical Journal studying the mass- versus light-weighted sizes of recently quenched and older quiescent galaxies at cosmic noon. The results show that infrared-based sizes closely trace the underlying stellar mass distribution, while optical measurements can systematically overestimate galaxy sizes, and point to a combination of progenitor bias and minor mergers driving size growth over time. Maike is now a PhD student at the University of Edinburgh.

*Clausen, M, Momcheva, I, Whitaker, K.E., Cutler, S., Bezanson, R., Dunlop, J., Grogin, N., Koekemoer, A., McLeod, R., McLure, R., Miller, T., Nelson, E., van der Wel, A., Wake, D., Wuyts, S.,* *The Evolution of Half-mass Radii and Color Gradients for Young and Old Quiescent Galaxies at 0.5 < z < 3 with JWST/PRIMER, 2025, ApJ, 993, 106.*

Lillian Wright (undergraduate group member from 2019-2023) recently published a paper in the Astrophysical Journal Letters detailing her study of the morphology of the first quiescent galaxies at z>3 using JWST imaging from the CEERS program. Lily is now a PhD student at SNU.