Ming-Yang Zhuang (庄明阳)

Research

My work combines multi-wavelength imaging and spectroscopy — much of it from JWST — to understand how active galactic nuclei and their host galaxies grow and evolve together across cosmic time, and to discover and characterize high-redshift transients.

Publications

I've published 16 first-author papers, 5 (co-)mentored papers, and ~40 contributed papers in total. Below are a few highlights; the full, up-to-date list is on SciX.

Research Highlights

2026 · arXiv:2609.38373

NEXUS: Discovery of a Luminous Young Transient at z = 5

M.-Y. Zhuang, Y. Shen, L. Hu, et al.

We report AT 2026abck, a transient in a star-forming galaxy at z = 5.017 found in NEXUS Year-2 NIRCam imaging — the first robustly detected z > 5 transient in a field without gravitational lensing. It brightened by more than 1.4 mag within ~12 rest-frame days, and its spectrum is consistent with a hot (~1.7×10⁴ K) blackbody with a radius of ~46 au and a luminosity of ~3×10⁴³ erg s⁻¹. Its offset from the galaxy center and its hot, UV-bright spectrum point to a core-collapse supernova caught only ~4–10 rest-frame days after explosion, hotter and more luminous than normal Type II supernovae at that phase. The host is a typical star-forming galaxy (M_* ≈ 10^9.8 M_⊙), ~2000 times more massive than the host of the lensed SN Eos at z = 5.13, showing that supernovae at z > 5 occur in a wide range of environments and that fast-cadence JWST blank-field surveys can catch them early.

SciX arXiv

2026 · arXiv:2609.06985

NEXUS: Transient Searches and First Results from Year One Observations

M.-Y. Zhuang, L. Hu, J. D. R. Pierel, et al.

We present the transient search in NEXUS, a multi-cycle JWST Treasury program in the North Ecliptic Pole field, using NIRCam F200W+F444W imaging taken every ~2 months over ~61.5 arcmin², plus NIRSpec/PRISM spectroscopy. In the first year we found 68 robust transients, with host photometric redshifts reaching z ≈ 6, and secured spectroscopic redshifts for 37 of them (~54%), including a tentative host association at z = 6.151. NEXUS finds supernovae most efficiently of all JWST surveys so far, at 6.6 per hour of imaging (2.6× COSMOS and 26× JADES), while its supernova rates broadly agree with other programs. We describe the reduction and detection pipeline in detail and release jwst_psfmc, a PSF photometry package that accounts for the correlated noise between pixels introduced by drizzling.

SciX arXiv Code

2026 · ApJ, 999, 31

NEXUS: A Spectroscopic Census of Broad-line AGNs and Little Red Dots at 3 ≲ z ≲ 6

M.-Y. Zhuang, J. Li, Y. Shen, et al.

Using NIRCam grism (WFSS) spectroscopy of the central 100 arcmin² of NEXUS, we identify 23 broad-line AGNs at 3 ≲ z ≲ 6, 15 of which are “Little Red Dots” (LRDs). LRDs have a number density of ~10⁻⁵ cMpc⁻³, which hints at a decline toward the lower end of this redshift range, and black-hole masses of ~10^6.3–8.4 M_⊙. Half of the LRDs show strong Balmer absorption, a sign of dense gas around the broad-line region. In most LRDs we detect extended host-galaxy light (hundreds of parsecs across) that contributes much, or even most, of the UV emission, largely explaining the puzzling UV upturn in LRD spectra. Their small-scale clustering suggests LRDs may be more strongly clustered than their low space density would imply.

SciX arXiv Journal

2024 · ApJ, 962, 93

Active Galactic Nuclei and Host Galaxies in COSMOS-Web. I. NIRCam Images, PSF Models and Initial Results on X-Ray-selected Broad-line AGNs at 0.35 ≲ z ≲ 3.5

M.-Y. Zhuang, J. Li, Y. Shen

We reduced all public COSMOS-Web NIRCam imaging available by mid-2023 (0.28 deg²) and built PSF models for it, finding that the NIRCam PSF changes noticeably over short times and varies randomly across the field. Combining NIRCam with archival HST imaging, we separate the central point source from the host galaxy for 143 X-ray-selected broad-line AGNs at 0.35 ≲ z ≲ 3.5, detecting host starlight in 142. About two-thirds of the hosts are star-forming, showing no sign that the AGN is shutting down star formation at the time we observe it, and the hosts follow nearly the same mass–size relation as galaxies without an AGN. Major mergers are rare (~7–22%), but bars, spiral arms and signs of minor mergers are everywhere, pointing to secular processes and minor mergers as important triggers of AGN activity.

SciX arXiv Journal

2023 · Nature Astronomy, 7, 1376

Evolutionary paths of active galactic nuclei and their host galaxies

M.-Y. Zhuang, L. C. Ho

We measured stellar masses, colors and structures for the host galaxies of ~11,500 broad-line AGNs at z ≤ 0.35, a sample nearly 40 times larger than any before it. Early- and late-type AGN hosts follow a similar relation between black-hole mass and stellar mass, and where an AGN sits on this plane is tied to its star formation and black-hole growth. This points to distinct evolutionary paths: galaxies above the relation mainly grow in stellar mass, those on it move along it, and those below it mainly grow their black holes. These paths suggest that radiative-mode feedback cannot quench the growth of AGNs below the relation, while kinetic-mode feedback hardly suppresses long-term star formation in those above it.

SciX arXiv Journal

CV

A summary of my education, positions, and service.

Contact

Department of Astronomy, University of Illinois Urbana-Champaign.