I study emission line galaxies with a preliminary focus on their spectra and physical properties. This is achieved through a combination of photometric and spectroscopic data from various instruments, as well as accurate modeling of galaxy spectra at high redshifts. Different SPS (Stellar Population Synthesis) modeling (including IMF), dust attenuation laws, and nebular emission contributions are considered to accurately interpret the observed spectra. Click here for a simple galaxy-spectrum-demo webapp that I create by Streamlit to illustrate the effects of different parameters on galaxy spectra.

 

 

Specifically, I combine JWST NIRCam imaging, NIRCam Grism spectroscopy and MIRI imaging to analyze the spectrophotometric properties of z > 6 emission line galaxies in COSMOS field. This is facilitated by the JWST Cycle 1 programs COSMOS-Web (PI: Kartaltepe) & PRIMER (PI: Dunlop), as well as cycle 3 program COSMOS-3D (PI: Kakiichi) which I am an active member of.

 

The main goals of my research include:

• - Understanding the characteristics of [OIII] emitters at z > 6, namely how their star formation, ISM conditions, and environment can be different from LBGs/UV-selected galaxies at similar redshifts.
• - Overcoming the challenges of cosmic variance by building a statistical sample of high-z emission line galaxies. This will refine the current understanding of high-z LF/SMF/clustering estimates.
• - Assessing the impact of AGN contribution within emission line galaxies at z > 6, and its implications for the coevolution of galaxies and supermassive black holes in the early universe.

Tracing the growth of supermassive black holes (SMBHs) since early cosmic times is of great importance. I am particularly interested in studying quasars/AGNs with the unique sensitivity of JWST, as well as ground-based facilities (e.g., Magellan, Keck) and future telescopes (including ELT).

 

Broad Line AGNs (BLAGN) at high redshifts show intriguingly red optical colors and sometimes blue rest-frame UV continua. These sources are often referred to as "LRDs", cyphering enormous valuable information about the seeding/growth of SMBHs and coevolution with their host galaxies. In JWST cycle 3, I have my PI program approved for 47 hours of NIRSpec MOS spectroscopy of a population of z>6 photometrically selected BH* candidates in the COSMOS field, which will provide crucial insights into the nature of premature SMBH growth and the co-evolution of SMBHs and their host galaxies in the early universe.

 

Also, I've worked with the Galfit (GalfitS, GalfitX) community at KIAA led by Prof. Luis Ho and Dr. Jinyi Shangguan, which enables state-of-the-art morphological+spectral decomposition of these BLAGN/LRDs into their host galaxy and AGN. Check out the Galfit community website here.

The Nancy Grace Roman Space Telescope (Roman) will revolutionize our understanding of the large-scale structure of the universe, by providing wide-field, high-resolution imaging and spectroscopy. In the future, I will be actively engaged in the exploitation of Roman slitless spectroscopy data to study the large-scale structure of the universe, including luminosity function, clustering.

 

TBD.

TBD.

 

TBD.

The distanct universe harbors a rich variety of galaxy morphologies, holding strong clues about the growth of galaxies and the structure of the universe. Connecting galaxy morphology with itself physical properties (e.g., stellar mass, SFR, metallicity) can shed light on the underlying physical processes driving galaxy evolution, while connecting morphology with dark matter halo and merger history can provide insights into the role of environment and interactions in shaping galaxies.

 

I look at two extremes of the high-z galaxy morphology spectrum: the morphological demographics of "normal" star-forming galaxies, as well as the most extreme outliers. For the former, I use statistical analysis to probe the behavior of galaxy morphology as a function of redshift and physical properties. For the latter, I attempt to reveal more physical interpretations of peculiarity with the aid of cosmological simulations.