Dongwoo Chung
I'm a CITA/Dunlap research fellow at the University of Toronto, working on observational extragalactic astrophysics and cosmology.
Here is an ADS library of articles that I've written or been involved in otherwise in some form.
I'm a CITA/Dunlap research fellow at the University of Toronto, working on observational extragalactic astrophysics and cosmology.
Here is an ADS library of articles that I've written or been involved in otherwise in some form.
My main research interest is in tracing the clustering of high-redshift galaxies through line-intensity mapping. The signals lie at a complex intersection of extragalactic astrophysics and cosmology, and cannot be treated simply as another cosmological signal with a Gaussian random field description. I use empirically motivated halo-based models and simulations of line-intensity signals to probe the information content of summary statistics including those beyond the power spectrum, such as one-point statistics for CO and [C ii] surveys, and more novel convolutional methods like the wavelet scattering transform.
My primary focus in the past has been on various aspects of the Carbon monOxide Mapping Array Project (COMAP), whose Pathfinder phase aims to measure the CO(1-0) line-intensity power spectrum at redshift 3. In November 2021, the collaboration produced a series of seven preprints on early science verification with the COMAP Pathfinder; the Astrophysical Journal published these papers in a July 2022 Focus Issue. I led the fifth paper in the series describing constraints from the Pathfinder upper limit and forecasts for future auto- and cross-spectrum analyses. Other publications that I have led look at various questions about how to model the COMAP target signal, with topics such as
I'm also very interested in the eventual expansion of COMAP to cover multiple frequency bands and thus multiple rotational transitions of CO at late reionisation, probing the excitation of CO and thus the environmental conditions of the cosmic average molecular cloud at a critical cosmological epoch. Forecasts for two- and three-band COMAP concepts show that they would enable line-intensity mapping measurements of physical parameters complementing observations of individual sources with ALMA and other facilities.
I have also written signal and sensitivity forecasts for the [C ii] line at high redshift as part of work done for the CCAT-prime science working group. I continue to be involved in forecasting as CCAT-prime/FYST breaks ground and targets first light in 2024, with spectroscopic instrumentation to follow shortly thereafter.
Beyond modelling, I recently joined the TIME collaboration and participated in the experiment's 2021-22 engineering run, providing instrument, analysis, and observing support. I expect to continue work on simulation pipeline design and end-to-end analysis pipeline testing.
As with COMAP, I'm also strongly interested in synergies between mm-wave line-intensity surveys and other large-scale structure surveys. I recently wrote a paper on cross-correlations between cosmic shear data and low-redshift CO lines in [C ii] surveys, which could simultaneously constrain low-redshift molecular gas and intrinsic alignments in weak lensing data. I'm also interested in the possibility of using cross-correlations to improve signal reconstruction, which should certainly be possible on the largest scales with linear covariance-based filtering.
During my PhD, I was directly involved in commissioning of the COMAP instrument, with tasks including writing the quicklook software, measuring the near-field beam pattern for prototype feeds, and looking for systematics such as standing waves in commissioning data. I also worked on the final stages of lab integration of the Argus receiver on the Green Bank Telescope as part of the instrument team.
I gained significant teaching experience while completing my PhD at Stanford, where I worked as a teaching assistant in three different introductory physics courses. Each time, a key goal was to employ active learning techniques to have students reflect on their problem-solving process and thus gain understanding in ways that they could not with rote methods. I've been lucky enough to work under the supervision of physics education faculty and staff at Stanford who have strong interests in improving undergraduate courses through better teaching methods.
I mentored one undergraduate summer student in 2018, who worked on COMAP gain calibration as well as calibrator assembly and testing. More recently, as part of SURP 2021 at the University of Toronto, I supervised one student on a project relevant to COMAP forecasting and co-supervised another student with Abigail Crites and Jenna Freudenberg on TIME analysis and simulation work. The former student, Ishika Bangari, was featured in a spotlight feature and received an honourable mention in that year's SURP poster presentations.
I have since supervised two further Canadian undergraduate students as part of the CITA SURF programme, one of whom is first author on a publication resulting from the SURF project.
Even as a non-tenured academic, I'm occasionally interested in the gorier side of academic departments, meaning that I've put some time into departmental service. Most recently I served on the Graduate Admissions Committee of the University of Toronto's Department of Astronomy and Astrophysics for the 2021-22 academic year. As the sole non-faculty member of the committee for that year, I participated in the review of submitted applications and in meetings of the committee at large (including applicant interviews) throughout the selection process.
Since 2022-23, I have been serving on the Astronomy Community Climate Committee, where I hope to continue considering equitable hiring and admissions practices, as well as refine resources on equity available to department members (including through the department website).
During much of my time at Stanford, I served on the Stanford Physics Equity and Inclusion Committee, as one of several graduate student representatives. As my first project, I led a redesign of the E&I committee's website to make more information more presentable to those interested. Working with the other student representatives, I also helped start a series of meetings with graduate students beyond the committee to identify action items in line with the E&I committee's strategic plan, with topics ranging from graduate admissions and first-year advising to health care subsidies and department climate.
I have also taken part in numerous education and public outreach events representing the Kavli Institute for Particle Astrophysics and Cosmology (KIPAC), from middle school science fairs to APS expos.
I obtained an AB in Physics (high honours) as part of Princeton's Class of 2014. Most of my independent work was done with the Gravity Group. I did one summer's work on ACTPol bias electronics and one summer plus a junior paper's worth of work on MuSE bolometer characterisation. I completed an experimental senior thesis on microwave SQUID multiplexing, supervised by Lyman Page.
My PhD thesis, supervised by Sarah Church, is available here. It largely comprises my first-author publications between 2017 and 2019 but also includes unpublished work on COMAP commissioning.
Beyond research and departmental service, I also served as webmaster for Stanford's Graduate Students in Applied Physics and Physics group, and participated frequently in the Meeting of Astrophysics Students at Stanford (MASS) as well as the KIPAC Statistics and Machine Learning Journal Club.
At CITA, I helped organise the 2021, 2022, and 2023 editions of the CITA National Jamboree, where CITA affiliates at Toronto and elsewhere gathered to present their research. I also co-organise activities for the Pan-Canadian Reionisation Focus Group, including a recent in-person workshop that took place in Toronto, and irregularly assist in running local CITA events like arXiv coffee chats and cosmology discussions.
My work for the 2022-23 academic year was supported in part by the Vincent and Beatrice Tremaine Postdoctoral Fellowship at CITA.
I maintain no active presence on social media. The best way to reach me is by email; hellothereGENERAL KENOBI@YOU ARE A BOLD ONEdongwooc.com is a virtual address meant to be more persistent than any given institutional email address.
If you're a spur-of-the-moment in-person sort of person, stop by the CITA offices on the 14th floor of Burton Tower, and we may meet by chance.