Arash Mirhosseini

Radio Astronomer | PhD Candidate in Physics
💻 GitHub
📍 Vancouver, BC, Canada

About Me

I am a PhD candidate in Physics at the University of British Columbia, working within the CHIME collaboration, specializing in radio interferometry, HI 21-cm absorption studies, and Radio Frequency Interference (RFI) mitigation.

Research Experience

Search for HI 21-cm absorption systems with CHIME
Sept. 2020 – Apr. 2026
University of British Columbia
Supervisor: Prof. Mark Halpern
  • Implemented compression scheme to manage the multi-petabyte data rate of CHIME Absorber data
  • Designed, developed, and implemented a comprehensive end-to-end pipeline for blind detection of HI 21-cm absorbers, establishing methodology directly applicable to SKA surveys
  • Discovered new HI 21-cm absorber at high redshift (z=2.327); paper submitted to ApJ (2025)
  • Developed open-source tools and algorithms for the broader radio astronomy community
High cadence kurtosis-based RFI excision for CHIME
Jan. 2019 – Sept. 2020
University of British Columbia
Supervisor: Prof. Mark Halpern
  • Developed real-time RFI excision system deployed on CHIME telescope
  • Created adaptive algorithms that improved data quality for intensity mapping and transient detection
  • Published methodology and shared codebase with CHIME collaboration members
Search for massive black holes via microlensing
Jan. 2017 – Jan. 2018
Linear Accelerator Laboratory, CNRS
Supervisor: Dr. Marc Moniez
  • Tested combining microlensing surveys to find long-duration microlensing events of massive objects
  • Published results in Mirhosseini & Moniez (2018), Astronomy & Astrophysics
Broadband spectral energy distribution of unusual quasars
Sept. 2015 – Jul. 2016
Leipzig University
Supervisor: Prof. Helmut Meusinger
  • Analyzed spectral characteristics of 3000 Å break quasars using multi-wavelength data
  • Published results in Meusinger et al. (2016), Astronomy & Astrophysics

Publications >2000 citations

CHIME collaboration et al.
Discovery of an HI 21 cm absorption system at z=2.327 with CHIME
The Astrophysical Journal, Submitted (2025), arXiv:2506.11269
CHIME collaboration et al.
A Detection of Cosmological 21 cm Emission from CHIME in Cross-correlation with eBOSS Measurements of the Lyman-alpha Forest
The Astrophysical Journal, 963, 23 (2024)
CHIME collaboration et al.
Detection of Cosmological 21 cm Emission with the Canadian Hydrogen Intensity Mapping Experiment
The Astrophysical Journal, 947, 16 (2023)
CHIME collaboration et al.
An Overview of CHIME, the Canadian Hydrogen Intensity Mapping Experiment
The Astrophysical Journal Supplement Series, 261, 29 (2022)
CHIME/FRB collaboration et al.
The First CHIME/FRB Fast Radio Burst Catalog
The Astrophysical Journal Supplement Series, 257, 59 (2021)
CHIME/FRB collaboration et al.
A bright millisecond-duration radio burst from a Galactic magnetar
Nature, 587, 54-58 (2020)
CHIME/FRB collaboration et al.
Periodic activity from a fast radio burst source
Nature, 582, 351-355 (2020)
A. Mirhosseini & M. Moniez
The MEMO project: Combining all microlensing surveys to search for intermediate-mass Galactic black holes
Astronomy & Astrophysics, 618, L4 (2018)
H. Meusinger, P. Schalldach, A. Mirhosseini, & F. Pertermann
Broad-band spectral energy distribution of 3000Å break quasars from the Sloan Digital Sky Survey
Astronomy & Astrophysics, 587, A83 (2016)

Education

Ph.D. in Physics
June 2026 (Expected)
University of British Columbia, Vancouver, Canada
Dissertation: Blind survey for HI 21-cm absorption systems with CHIME
Supervisor: Prof. Mark Halpern
MSc in Astronomy
Sept. 2020
University of British Columbia, Vancouver, Canada
Thesis: High-Cadence RFI excision with CHIME
Supervisor: Prof. Mark Halpern
MSc in Physics
Sept. 2018
Paris-Saclay University, Paris, France
Thesis: Search for intermediate-mass Galactic black holes with microlensing
Supervisor: Dr. Marc Moniez
BSc in Physics
Aug. 2016
Leipzig University, Leipzig, Germany
Thesis: Broadband spectral energy distribution of unusual quasars
Supervisor: Prof. Helmut Meusinger

Major Awards & Scholarships

Buchalter Cosmology First Prize (as part of CHIME collaboration)
2024
Awarded for groundbreaking cosmology work in Detection of Cosmological 21 cm Emission paper
NSERC Brockhouse Prize (as part of CHIME collaboration)
2022
Recognizes outstanding collaborative achievements in natural sciences and engineering
Governor General's Innovation Award (as part of CHIME collaboration)
2020
Honors contributions to Canada's success and inspiration for future generations
Excellence Initiative (IDEX) Paris-Saclay Scholarship
2016–2018
Full merit-based scholarship for students with proven high academic level and aspiring research careers

Technical Skills

Core Computing

  • Python (8+ years, NumPy, SciPy, Astropy, etc.)
  • High Performance Computing (Compute Canada/Digital Research Alliance clusters)
  • Linux/Unix & Shell Scripting
  • Version Control (Git/GitHub)

Signal Processing

  • Large-scale interferometric data processing
  • Advanced statistical methods for signal detection
  • RFI identification and mitigation
  • Scalable data pipeline development

Languages

  • English (Fluent)
  • Persian (Native)

Contact

I'm always interested in discussing potential collaborations. Feel free to reach out via email or connect with me on GitHub.

Email: arashmirhosseini@phas.ubc.ca
GitHub: github.com/arashcosmology