Extragalactic Astrophysics × Data Science

Dr. Abdurro’uf

Sullivan Prize Fellow · Department of Astronomy · Indiana University

I turn pixels into physics. I map the internal structure of galaxies across 12 billion years of cosmic time and connect telescope data to simulations through forward modeling and machine-learning inference.

Resolved SED fitting Simulation-based inference
simulated particlesobserved pixels
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Portrait of Abdurro’uf
Dr. Abdurro’ufSullivan Prize Fellow, Indiana University
Bloomington, IN, USA
About

Bridging observations, simulations, and machine learning

Galaxies are not points. The processes that build and quench them, including gas inflow, compaction, stellar and black-hole feedback, mergers, and environment, act in specific places within galaxies and on specific timescales.

I am an extragalactic astrophysicist working at the intersection of astrophysics and data science. I map the spatially resolved physical properties of galaxies with imaging and spectroscopic data from various telescopes (including HST, JWST, and Euclid), and compare them with cosmological hydrodynamical simulations. I build the open-source tools that link the two: piXedfit for spatially resolved SED fitting, together with its successor piXedfit2 (in development), which combines traditional Bayesian SED fitting and machine-learning inference in one modular, interactive framework; GalSyn for forward-modeling simulations into realistic observations; and GalSyn-SBI, a set of simulation-based inference (SBI) networks that recover global and resolved galaxy properties in under a second. These tools are built for the coming flood of data from Euclid, Roman, and Rubin/LSST.

I was PI of JWST Cycle 2 program GO 4246 on the study of a merging galaxy at the cosmic dawn epoch, and I am an active member of the Euclid Consortium and the Roman Science Collaboration, and a co-investigator on more than a dozen JWST programs. Before Indiana, I was a postdoctoral fellow at Johns Hopkins University and ASIAA (Taiwan), and I earned my PhD at Tohoku University (Japan).

Observe

Resolved maps of galaxies from z ~ 0 to the cosmic dawn epoch with JWST, HST, and Euclid.

Simulate

Forward-model TNG, EAGLE/FLARES, and SIMBA into realistic mock data.

Infer

Train calibrated SBI networks on mocks and apply them to millions of galaxies.

Research

From pixels to physics

One question drives my program: how do galaxies assemble their internal structures and shut down their star formation across 12 billion years, and which physical processes set the routes they take? I answer it with a closed loop between simulations and survey data.

Full research program →
RESEARCH LOOP From Pixels to Physics 01 Simulations TNG · EAGLE · SIMBA 02 GalSyn forward-modeled mocks 03 SBI networks GalSyn-SBI · amortized SBI 04 Resolved maps M*, SFR, age, Z, dust 05 Hypothesis tests quenching · assembly 06 Physics constraints feedback · dust · IMF
  1. Simulations provide labeled ground truth: galaxies whose full history is known.
  2. GalSyn forward-models them into realistic synthetic data (HST, JWST, Euclid, Roman, and Rubin).
  3. SBI networks (GalSyn-SBI) trained on these mocks infer global and resolved properties in <1 s per galaxy.
  4. Applied to real surveys, they yield resolved maps and SFHs for 105–107 galaxies.
  5. These maps test hypotheses about quenching routes and structural assembly.
  6. The results constrain the physics in the next generation of simulations.

Research themes

Publications

72 papers on how galaxies form, grow, and quench

My papers span spatially resolved stellar populations from the local Universe to cosmic dawn, JWST spectroscopy of galaxies within the first 500 Myr, Euclid survey results, and new methods in SED fitting, forward modeling, and machine learning.

Resolved stellar populations Galaxies at z > 10 Star clusters & clumps Quenching Methods & software
Software

Open-source tools for the survey era

Public, documented Python packages for resolved galaxy analysis and simulation forward modeling.

All software →

GalSyn

Galaxy Synthesizer · ApJS 2026

Forward-models hydrodynamical simulations into realistic imaging and IFS data, together with the ground-truth property maps behind them.

forward modelingmock observations

piXedfit

Pixelized SED fitting · ApJS 2021

An end-to-end package for spatially resolved SED fitting: image processing, PSF matching, imaging–IFS combination, pixel binning, and Bayesian SED fitting.

resolved SED fittingBayesian

piXedfit2

Next-generation piXedfit · in development

A modular, pythonic rewrite of piXedfit for interactive resolved SED analysis from survey mosaics, with five inference backends: RDSPS, MCMC, Dense Basis, Bagpipes, and SBI.

resolved SED fittingSBI

GalSyn-SBI

Resolved galaxy inference · in development

Simulation-based inference that turns multiband images into calibrated maps of stellar mass, SFR, age, metallicity, and dust in under a second, using a U-Net and normalizing flows trained on GalSyn mocks.

normalizing flowsU-Net
Curriculum Vitae

Career at a glance

2025 – present

Sullivan Prize Fellow

Department of Astronomy, Indiana University, USA

2022 – 2025

Postdoctoral Fellow

Johns Hopkins University, USA

2018 – 2022

Postdoctoral Fellow

Academia Sinica Institute of Astronomy and Astrophysics, Taiwan

2013 – 2018

MSc & PhD (Doctor of Science)

Astronomical Institute, Tohoku University, Japan

2009 – 2013

BSc in Physics

Brawijaya University, Indonesia

Highlights

Recent news

  • 2026GalSyn I, the forward-modeling framework and first data release from IllustrisTNG, is published in ApJS 286, 60.
  • 2026Joined the Roman Science Collaboration; co-I of Roman Cycle 1 GI program R-HIVE.
  • 2026Our study of young star clusters and clumps in the lensed Cosmic Spear at z = 6.2 is accepted in ApJ.
  • Aug 2025Started as a Sullivan Prize Fellow at Indiana University.
  • 2025Led Euclid preparation LXXIII, which tests resolved stellar populations of local galaxies with TNG50-based Euclid mocks.
  • 2024First resolved [O II] doublet and direct electron-density measurement at z > 10 (ApJ 973, 47), from my JWST GO 4246 program.