About Me

I am a Postdoctoral Research Fellow in the Department of Physics & Astronomy at University College London (UCL), where I have been based since June 2021. I completed my PhD in Cosmology at the University of Edinburgh, supervised by John Peacock, and was awarded the Winton Prize for the best PhD thesis in Astronomy and the Scottish University Physics Alliance Prize Studentship. I previously studied MMathPhys at the University of Oxford.

Research Interests: My research sits at the intersection of observational cosmology and large galaxy surveys. I work on photometric redshift estimation and calibration, large-scale structure, weak gravitational lensing, galaxy–CMB cross-correlations, and tests of early-Universe physics using ultra-large-scale clustering. I am also interested in beyond two-point statistics, including cosmic voids and higher-order probes. I am involved in major surveys including LSST/Rubin, DESI, DES, and Euclid.

Full publication list: NASA ADS

Research

Calibrating redshift distributions at z > 2 with Lyman-α forests
Accurate photometric redshift (photo-z) calibration is critical for upcoming surveys like LSST. I developed a method to calibrate high-redshift tail of galaxy redshift distributions using cross-correlations with Lyman-α forests from quasar spectra, extending clustering-based calibration beyond z~2 where traditional spectroscopic overlap breaks down. MNRAS (2026)

RAIL: Redshift Assessment Infrastructure Layers
As co-lead of the RAIL topical team within LSST DESC, I contribute to the infrastructure software for photometric redshift estimation and validation for the Rubin Observatory era. RAIL provides a modular, community-maintained framework for stress-testing photo-z algorithms at scale across simulated and real datasets. OJAp (2026)

Impact of survey spatial variability on redshift distributions for LSST
I studied how spatial survey systematics — depth variations, stellar density, seeing — bias estimated galaxy redshift distributions and propagate into cosmological 3×2-point analyses, with direct implications for how LSST data must be processed. MNRAS (2024)

Galaxy trough and peak profiles with DES Year 3
I measured trough and peak profiles — underdense and overdense lines of sight — using DES Y3 redMaGiC galaxies and the weak lensing mass map, providing new constraints on galaxy bias and the matter distribution beyond standard two-point functions. MNRAS (2025)

Structure growth from CMB lensing: ACT DR6 × DESI Legacy Imaging
In collaboration with the ACT team, I contributed to measurements of the growth of cosmic structure from cross-correlations of DESI Legacy Imaging galaxies with high-fidelity CMB lensing maps from ACT DR6 and Planck PR4. PRD (2024)

Publications

Full list: NASA ADS

First-author papers

  1. Calibrating redshift distribution at z > 2 with Lyman-α forest cross-correlations
    Q. Hang, L. Casas, W. d'Assignies, W. Turner, A. Font-Ribera, B. Joachimi
    MNRAS (2026) · DOI
  2. Biasing from galaxy trough and peak profiles with the DES Y3 redMaGiC galaxies and the weak lensing mass map
    Q. Hang et al.
    MNRAS, 546 (2025) · DOI
  3. Impact of survey spatial variability on galaxy redshift distributions and the cosmological 3×2-point statistics for LSST
    Q. Hang et al.
    MNRAS, 535, 2970 (2024) · DOI
  4. Galaxy and Mass Assembly (GAMA): Probing galaxy-group correlations in redshift space with the halo streaming model
    Q. Hang, J. A. Peacock, S. Alam, Y-C. Cai, K. Kraljic, M. van Daalen, M. Bilicki, B. W. Holwerda, J. Loveday
    MNRAS, 517, 1365 (2022) · arXiv
  5. Stacked CMB lensing and ISW signal around super structures in the DESI Legacy Survey
    Q. Hang, S. Alam, Y. Cai, J. A. Peacock
    MNRAS, 507, 510 (2021) · arXiv
  6. Galaxy clustering in the DESI Legacy Survey and its imprints on the CMB
    Q. Hang, S. Alam, J. A. Peacock, Y. Cai
    MNRAS, 501, 1481 (2021) · arXiv

Selected contributed papers

  1. Redshift Assessment Infrastructure Layers (RAIL): Rubin-era photometric redshift stress-testing and at-scale production
    The RAIL Team et al. (incl. Q. Hang as corresponding author)
    OJAp, Vol. 9 (2026) · DOI
  2. The Atacama Cosmology Telescope DR6 and DESI: Structure growth measurements from the cross-correlation of DESI Legacy Imaging galaxies and CMB lensing from ACT DR6 and Planck PR4
    F. J. Qu, Q. Hang et al.
    PRD, 111, 103503 (2024) · DOI
  3. Propagating data-driven galaxy redshift distribution uncertainties in 3×2-pt analyses
    J. Ruiz-Zapatero, Q. Hang, Y. Zhang, B. Joachimi, J. Zuntz, and the LSST DESC
    In collaboration review
  4. Uniform Rolling: An LSST Observing Cadence Offering Sufficient Survey Uniformity for Comprehensive Cosmological Analysis
    B. Leistedt et al. (incl. Q. Hang)
    Submitted to ApJ Supplements

Service & Community

Leadership in LSST DESC:

  • Co-convenor, photometric redshift working group, LSST DESC (Jan 2026 – present)
  • Co-lead, RAIL topical team, LSST DESC (Jan 2024 – Dec 2025)
  • UK in-kind contributor to LSST DESC infrastructure and software development
  • Member, DESC EDI Committee (2026 – present)
  • Member, DESC Paper Review Committee (2025 – present)
  • Member, DESC Collaboration Council Nomination Committee (2024)
  • Member, DESC Scientific Organising Committee, July 2023 Collaboration Meeting

Teaching & Supervision:

  • Co-supervisor, PhD student, UCL (2025 – present)
  • Co-supervisor, MSc/MSci Astrophysics theses, UCL (2022, 2023, 2025, 2026)
  • Supervisor, MAPS summer studentship, UCL (2025)
  • Teaching Assistant (tutorials and computing labs), UCL (2022–2023)
  • Teaching Assistant (tutorials), University of Edinburgh (2017–2021)

Other Community Roles:

  • Panellist, Peer Review Panel, NASA Nancy Grace Roman Space Telescope (2023)
  • Organiser, London Cosmology Discussion Meeting and weekly seminar series
  • Postdoctoral Representative, Departmental EDI Committee, UCL

Contact

Email: e.hang@ucl.ac.uk

Address: Department of Physics & Astronomy, University College London, Gower Street, London, UK, WC1E 6BT