SAZERAC 21cm 2022

14-17 March 2022

Location: Zoom, YouTube, and Slack

Due to the sustained interest in SAZERAC we have decided to split this year's main meeting in two with meetings focussing on the 21cm signal and galaxies.

Observations of the 21 cm signal have the potential to provide precision constraints on astrophysics and cosmology from the Dark Ages to the present day (150 >~ z >~ 0). The construction of new radio telescopes over the last decade has led to significant progress including a potential first detection of the sky-averaged 21 cm signal at Cosmic Dawn, physically constraining upper limits on the 21 cm power spectrum during the Epoch of Reionization and detections of the 21 cm signal in cross-correlation at lower redshifts. This SAZERAC meeting will bring the 21 cm cosmology community together to update each other on our work, discuss the remaining challenges ahead and foster new ideas and collaborations. Talk sessions will be organised around the following broad topics:

  • Updates on experiments and observations
  • Analytical and numerical modelling of the signal
  • Instrumental characterisation, modelling and calibration
  • Characterisation and mitigation of foregrounds
  • Theoretical and observational constraints
  • Cross-correlations between the 21-cm line and other signals
  • Prospects for lunar and space-based observations


Links providing access to the SAZERAC Zoom and Slack will be distribution via the SAZERAC mailing list. The maximum number of people accomodated by Zoom is 500 and access is provided on a first-come first-served basis. However, the conference will also live stream via our YouTube channel.

Abstract Submission

We invite researchers to submit their abstracts on this topic. During the selection for the contributed talks, priority will be given to graduate students and early-career scientists. To apply to give a talk we invite researchers to submit their abstracts on this topic via this link by 14 February 2022. To participate otherwise you need only sign-up for the general SAZERAC mailing list through which connection info will be shared. Additionally, discussion on the subject is encouraged between the participants through a Slack channel hosted by the SAZERAC team.


The SOC is responsible for defining the objectives and scientific themes of the meeting as well as selecting the live talks.

  • Abhirup Datta (IIT Indore)
  • Adélie Gorce (McGill University)
  • Suman Majumdar (IIT Indore)
  • Garrelt Mellema (Stockholm University)
  • Raul Monsalve (Berkeley Space Sciences Laboratory)
  • Steven Murray (Arizona State University)
  • Abinash Kumar Shaw (Open University of Israel)
  • Jonathan Pritchard (Imperial College London)
  • Peter Sims (McGill University)
  • Cathryn Trott (Curtin University)
  • Stephen Wilkins (University of Sussex)


Note that most of North America will switch to daylight saving time the day before the start of the conference. You can download a PDF copy of the schedule here.

Recorded Talks

Available on YouTube.

  • Shikhar Mittal, Tata Institute of Fundamental Research, Explaining the LWA/ARCADE radio excess by primordial black holes
  • Maria Berti, SISSA – Trieste, Constraining beyond Lambda-CDM models with 21cm intensity mapping forecasted observations combined with latest CMB data
  • Kangning Diao, Tsinghua University, Reionization parameter inference from the 3D Minkowski Functionals of the 21 cm signal
  • Paulo Montero-Camacho, Tsinghua University, Unveiling the astrophysics of reionization in the post-reionization era (with DESI)
  • Meng Zhou, Tsinghua University, A new semi-numerical method for simulating cosmic reionization and IGM heating
  • Chandra Shekhar Murmu, Indian Institute of Technology Indore, Impact of light-cone on the [C II] and [H I] 21cm signal statistics from the EoR
  • Teppei Minoda, University of Melbourne, Probing isocurvature perturbations with 21-cm global signal
  • Camila Paiva Novaes, Instituto Nacional de Pesquisas Espaciais, On the recoverability of the BAO signal on realistic BINGO HI IM simulations

Updates on experiments and observations 1

Time: Day 1, 15:00 - 16:50 GMT / 8:00 - 9:50 PDT / 11:00 - 12:50 EDT
Chair: Josh Dillon (Berkeley)
  • 15:00 - 15:05 Peter Sims & Adélie Gorce, Welcome to SAZERAC 21 cm 2022
  • 15:00 - 15:35 Matt Dobbs (invited), McGill University, Observations of the 21cm signal at low redshift
  • Break (10 mins)
  • 15:45 - 16:00 Devin Crichton, ETH Zürich, HIRAX: Status and Systematics
  • 16:00 - 16:20 Shilpa Ranchod (invited), Max Planck Institute for Radio Astronomy, HI in and lensed by the HFF clusters: A deep MeerKAT search
  • 16:20 - 16:35 Wenkai Hu, LAM - Laboratoire d’Astrophysique de Marseille, Extending the HI survey limit to higher redshifts using FAST
  • 16:35 - 16:50 Peter Timbie, University of Wisconsin – Madison, The Tianlai Dish Array

Updates on experiments and observations 2

Time: Day 1, 17:30 - 19:50 GMT
Chair: Ronniy Joseph (McGill University)
  • 17:30 - 18:00 Aaron Parsons (invited), Berkeley, 21 cm observations at high redshift Break (15 mins)
  • 18:15 - 18:35 Bharat Gehlot, Kapteyn Institute, University of Groningen, Degree-Scale Galactic Radio Emission at 122 MHz around the North Celestial Pole with LOFAR-AARTFAAC
  • 18:35 - 18:50 Hugh Garsden, Queen Mary University of London, 21 cm power spectrum at 48 MHz (z = 28) from the Owens Valley Long Wavelength Array
  • 18:50 - 19:05 Kelly Foran, McGill University, A Progress Report on PRIZM Data Analysis and Calibration
  • 19:05 - 19:20 Jeffrey Peterson, Carnegie Mellon University, The High-Z 21-cm Global Spectrometer
  • 19:20 - 19:35 Nicholas Kern, MIT, First Limits from HERA: Advancements in Systematic Modeling and Power Spectrum Estimation For More Robust Limits
  • 19:35 - 19:50 Josh Dillon, UC Berkeley, What's Next for the Hydrogen Epoch of Reionization Array?

Characterisation and mitigation of foregrounds

Time: Day 2, 9:00 - 10:50 GMT
Chair: José Fonseca (Universidade do Porto)
  • 9:00 - 9:20 Saurabh Singh (invited), Raman Research Institute, On the detection of a cosmic dawn signal in the radio background
  • 9:20 - 9:35 Jaiden H Cook, ICRAR, Investigating the contribution of extended radio sources in the EoR power spectrum
  • 9:35 - 9:50 Ce Sui, Tsinghua University, Identification of Low-intensity Radio Frequency Interference with Machine Learning
  • Break (15 mins)
  • 10:05 - 10:20 Michael Pagano, McGill University, Accounting for uncertainties in the low-frequency radio sky maps in REACH Global 21 cm signal analysis
  • 10:20 - 10:35 Elimboto Yohana, Dar Es Salaam University College of Education, Recovering the 21-cm signal from simulated FAST intensity maps
  • 10:35 - 10:50 Haochen Wang, MIT, A Systematics-Robust 21 cm Foreground Removal Algorithm

Instrumental characterisation, modelling and calibration

Time: Day 2, 15:00 - 16:45 GMT
Chair: Bharat Gehlot (Kapteyn Institute)
  • 15:00 - 15:30 H. Cynthia Chiang (invited), McGill University, Instrument characterization for 21cm intensity mapping arrays
  • Break (15 mins)
  • 15:45 - 16:00 Ian Roque, University of Cambridge, Advanced Bayesian calibration pipeline for global 21-cm experiments
  • 16:00 - 16:15 Hyoyin Gan, Kapteyn Astronomical Institute, Comparison of direction dependent calibration performance of DDECal and SAGECal in the LOFAR-EoR context
  • 16:15 - 16:30 Ian Hendricksen, McGill University, Prototyping for the Canadian Hydrogen Observatory and Radio transient Detector with the Deep Dish Development Array
  • 16:30 - 16:45 Joelle-Marie Begin, McGill University, Developments on a new low-noise amplifier and antenna for ALBATROS

Cross-correlations between the 21-cm line and other signals 1

Time: Day 2, 17:45 - 19:30 GMT
Chair: Seth Siegel (McGill University)
  • 17:45 - 18:15 Jordan Mirocha (invited), McGill University, Cross-correlations in the EoR: expectations, latest results, and future prospects
  • Break (15 mins)
  • 18:30 - 18:45 Rahul Kannan, Harvard University, Predictions for multi-tracer line intensity mapping in the epoch of reionization
  • 18:45 - 19:00 Hannah Fronenberg, McGill University , An End-to-End Pipeline For 21 cm x LIM Cross-Correlations
  • 19:00 - 19:15 Eli Visbal, University of Toledo, Cross-Correlation of 21cm Observations and JWST Pencil-Beam Galaxy Surveys
  • 19:15 - 19:30 Paul La Plante, UC Berkeley, 21cm, the CMB, and Galaxies during Reionization: Three Sides of the Same Coin

Analytical and numerical modelling of the signal 1

Time: Day 3, 9:00 - 10:45 GMT
Chair: Sambit Giri (University of Zurich)
  • 9:00 - 09:30 Anastasia Fialkov (invited), Cambridge University, Theoretical modelling at high redshift
  • Break (15 mins)
  • 09:45 - 10:00 Yidong Xu, National Astronomical Observatories, Chinese Academy of Sciences, Effects of Small-scale Absorption Systems on Neutral Islands during the Late Epoch of Reionization
  • 10:00 - 10:15 Aishrila Mazumder, Indian Institute of Technology Indore, End-to-end simulation pipeline for sensitive Interferometric Observations
  • 10:15 - 10:30 Barun Maity, NCRA-TIFR, Efficient Modelling of Cosmic Reionization using SCRIPT
  • 10:30 - 10:45 Stefano Camera, University of Turin, Baryon acoustic oscillations from HI intensity mapping: the importance of cross-correlations in the monopole and quadrupole

Theoretical and observational constraints

Time: Day 3, 11:45 - 13:35 GMT
Chair: Suman Chatterjee (NCRA-TIFR)
  • 11:45 - 12:00 Anshuman Tripathi, Indian Institute Of Technology Indore (IIT Indore), Extracting the HI 21cm signal from CD/EoR from ground-based observations using Artificial Neural Networks
  • 12:00 - 12:15 Isabella Paola Carucci, University of Turin, Blind Foreground Subtraction Challenge for SKAO HI Intensity Mapping
  • 12:15 - 12:30 Janakee Raste, TIFR, Mumbai, Implications of the z ~ 5–6 Lyman-α forest for 21cm Experiments
  • Break (15 mins)
  • 12:45 - 13:00 Harry Thomas Jones Bevins, Cavendish Astrophysics, University of Cambridge, A comprehensive Bayesian re-analysis of the SARAS2 data from the Epoch of Reionization
  • 13:00 - 13:15 Charlotte Mason, DAWN, University of Copenhagen, Inferring astrophysics and cosmology at Cosmic Dawn using 21cm observations
  • 13:15 - 13:35 Stefan Heimersheim, Julian Muñoz, Yuxian Qin (invited), Theoretical Interpretation of the First HERA upper limits

Analytical and numerical modelling of the signal 2

Time: Day 3, 15:00 - 16:45 GMT
Chair: Caroline Heneka (University of Hamburg)
  • 15:00 - 15:30 Alkistis Pourtsidou (invited), University of Edinburgh, 21cm intensity mapping: from pathfinder data analysis to future surveys preparation
  • Break (15 mins)
  • 15:45 - 16:00 Ivelin Georgiev, The Oskar Klein Centre, Department of Astronomy at Stockholm University, Impact of the Mean Free Path on the Large Scale 21-cm Power Spectrum from Reionization
  • 16:00 - 16:15 Zhaoting Chen, Jodrell Bank Centre for Astrophysics, Interferometric Intensity Mapping in the Low-Redshift Universe
  • 16:15 - 16:30 Thomas Gessey-Jones, University of Cambridge, Probing the First Stars with the Cosmic Dawn 21-cm Signal
  • 16:30 - 16:45 Joe Lewis, University of Heidelberg, The signature of galaxy formation models in the 21cm line

Cross-correlations between the 21-cm line and other signals

Time: Day 4, 15:00 - 16:50 GMT
Chair: Isabella Carucci (University of Turin)
  • 15:00 - 15:15 Denis Tramonte, Purple Mountain Observatory (PMO), The neutral cosmic web from stacks on 21-cm intensity maps
  • 15:15 - 15:30 Melis Irfan, University of the Western Cape, MeerKLASS: large area 21cm intensity mapping using the MeerKAT array
  • 15:30 - 15:45 Caroline Heneka, University of Hamburg, Learning the 21cm signal - From sources to tomography
  • Break (15 mins)
  • 16:00 - 16:15 Ian Hothi, Imperial College, Synergies between interferometers and upcoming surveys, to study the end of the EoR
  • 16:15 - 16:30 Steve Cunnington, University of Edinburgh, MeerKAT HI intensity mapping cross-correlations with overlapping galaxy surveys at z~0.4
  • 16:30 - 16:50 Seth Siegel (invited), McGill University, Detection of 21cm Emission from Large-scale Structure with CHIME

Prospects for lunar and space-based observations

Time: Day 4, 20:30 - 22:15 PDT / Day 4, 23:30 - Day 5, 01:15 EDT / Day 5, 3:30 - 5:15 GMT / 9:00 - 10:45 IST / 11:30 - 13:15 CST
Chair: Udaya Shankar Narayana Rao
  • 3:30 - 4:00 Gregg Hallinan (invited), Caltech, Space-based observations
  • Break (15 mins)
  • 4:15 - 4:30 Xuelei Chen, National Astronomical Observatories, Chinese Academy of Science, Discovering the Sky at the Longest wavelength using lunar orbit array
  • 4:30 - 4:45 Yuan Shi, National Astronomical Observatories, Chinese Academy of Science, Lunar Orbit Measurement of Cosmic Dawn 21 cm Global Spectrum
  • 4:45 - 5:00 Fengquan Wu, National Astronomical Observatory, Beijing, China, Measuring 21cm global spectrum on the lunar orbit and its ground testing
  • 5:00 - 5:15 Mayuri S. Rao, Raman Research Institute, PRATUSH : a proposed Indian lunar orbiter experiment for studying the Cosmic Dawn

Code of Conduct

Attendance at SAZERAC is not a right but a privilege, and attendees are expected to behave professionally. The SAZERAC organizers are committed to providing an atmosphere that encourages the free expression and exchange of scientific ideas.

This document establishes a code of conduct for all attendees of SAZERAC. By participating in SAZERAC in any way, including as an attendee, a presenter, or an organizer, you agree to abide by this code of conduct. Failure to adhere to this code of conduct in all SAZERAC-related circumstances, including in the main session webinars, in the Slack channels, other SAZERAC-related events, or any in person, telephone, or other electronic communication related to SAZERAC, will result in removal from all conference events.

Our scientific community values all members, regardless of (alphabetically) age, cultural background, disability, ethnicity, gender, gender expression, gender identity, marital status, nationality, physical appearance, political affiliation, pregnancy, race, religious beliefs, sexual orientation, socio-economic status, and status as a caregiver (including as a parent). The ability of SAZERAC to allow our community to share its research results and promote the careers of junior attendees depends critically on maintaining a culture of inclusivity, where all voices are respected and heard.

SAZERAC will not tolerate verbal, nonverbal, physical, or sexual harassment or bullying of any kind. Behavior and language acceptable to one person may not be to another. Unwelcome attention, threatening or abusive language, insulting, hurtful, or disrespectful comments, are strictly banned from SAZERAC. Members must make every effort to ensure that words and actions communicate respect for others, regardless of opinion regarding the person or their scientific results.

SAZERAC places a high priority on eliminating sexual harassment in any form from the workplace. As a rule, sexual advancements should not take place in any professional setting, including social events related to a professional event. Members should be especially conscientious of real or perceived power gradients such as seniority, status, or reputation, that may place a member in a vulnerable position.

SAZERAC is not a public event. All attendees must register via the website, and should not share the connection information to Zoom or Slack with non-registered people. When connecting to Zoom or slack, all attendees should use their own name, and not attempt to misrepresent themselves.

During SAZERAC sessions, the Session Chair is in charge. Speakers must keep to their allotted time, ideally using a timer. If they exceed their time, their question time will be reduced, and if they speak through all of the question time, they will be disconnected. When asking questions of speakers, please be professional, courteous, and polite. If a participant engages in obvious harassing behavior during the presentations, the Chairs may take any action they deem appropriate, including warning the offender or removing them from the conference.

SAZERAC participants who believe that they have witnessed or been negatively impacted by a possible violation of the Code of Conduct should contact the SOC by emailing to initiate a complaint, including any available evidence (e.g., screenshots) in their email. If a majority of the SOC concurs that this code has been violated, the offender will be immediately removed from all SAZERAC events. The offender will then be contacted by the SOC, and will have the opportunity to appeal the decision. This appeal will be considered by the SOC, whose decision will be final.