Joint Appointment Member

Dr. Chen, Yu-Jung (Joint Appointment Professor
Distinguished Professor/Chairman, NCU Dept. of Physics)

陳俞融博士大頭照

Information

Research Overview

Exploring how energetic radiation transforms cosmic ice and dust into the molecular complexity observed throughout the Universe

The Photoprocessing & Spectroscopy Laboratory (PPS Lab) at National Central University is dedicated to understanding how energetic radiation drives the physical and chemical evolution of cosmic ice and dust. Interstellar dust grains coated with molecular ices are the birthplaces of molecular complexity in the Universe, where simple species evolve into increasingly complex molecules during the formation of stars and planetary systems. Our research seeks to reveal the fundamental molecular processes occurring in these environments and to establish the laboratory foundation for interpreting modern astronomical observations.

To achieve this goal, we recreate realistic interstellar and circumstellar environments under ultra-high-vacuum and cryogenic conditions. Our laboratory combines complementary energetic sources—including vacuum ultraviolet (VUV) photons, synchrotron-based extreme ultraviolet (EUV) and soft X-rays, energetic electrons, and hydrogen/deuterium atom beams—with in situ Fourier-transform infrared (FTIR) spectroscopy and mass spectrometry. These experimental capabilities enable real-time investigations of molecular dissociation, surface reactions, diffusion, photodesorption, ion formation, and radiation-driven chemical evolution in astrophysical ice analogs.

A major focus of our current research is the chemistry occurring at the dust–ice interface. Rather than treating interstellar dust as a passive substrate, we investigate how its composition, morphology, and porosity regulate ice growth, molecular diffusion, desorption, and infrared spectral signatures. Our recent studies demonstrate that porous carbonaceous dust significantly modifies the structure and thermal evolution of abundant interstellar molecules such as CO, CO2, and H2O, highlighting the critical role of molecule–surface interactions in shaping astronomical spectra. These results provide new constraints for interpreting observations from the James Webb Space Telescope (JWST) and for improving astrochemical models of star-forming regions and protoplanetary disks.

Looking ahead, PPS Lab continues to expand its capabilities in wavelength-dependent laboratory astrochemistry and multi-source irradiation experiments to simulate increasingly realistic cosmic radiation environments. By integrating advanced laboratory instrumentation with astronomical observations and theoretical modeling, we aim to establish molecular-level benchmarks that connect microscopic physical processes with the large-scale chemical evolution of star- and planet-forming environments. Through interdisciplinary collaborations, our long-term vision is to bridge laboratory astrochemistry and observational astronomy, providing fundamental insights into how radiation, dust, and ice collectively shape the chemical evolution of the Universe.

期刊論文

1. Yi-Hsuan Chiu, Tushar Suhasaria, Cornelia Jäger, Chun-Yi Lee, Ko-Ju Chuang, Thomas Henning, and Yu-Jung Chen Molecule-specific diffusion and desorption of interstellar ices on carbonaceous dust , Astronomy & Astrophysics manuscript no. aa61379-26 (2026/07)
2. C.-Y. Lee, K.-J. Chuang, Y.-Y. Hsu, C. Jäger, Th. Henning, and Y.-J. Chen, Extreme-ultraviolet Photochemistry in Water-covered Carbonaceous Dust Analogs: Effects of Dust Thickness and Hydrogen Content , The Astrophysical Journal, Volume 1004, Number 2 (2026/06)
3. Jiménez-Escobar, A.; Ciaravella, A.; Cecchi-Pestellini, C.; Sie, N.-E.; Lee, C.-Y.; Huang, C.-H.; Caro, G. M. Muñoz; Chen, Y.-J., Laboratory simulations of ice growth in space: An expected nonuniform ice mantle composition , Astronomy & Astrophysics, Volume 686, id.A39, 7 pp. (2024/06)
4. Angela Ciaravella, Guillermo M. Muñoz Caro, Antonio Jiménez-Escobar, Cesare Cecchi-Pestellini, Li-Chieh Hsiao, Chao-Hui Huang, and Yu-Jung Chen, X-ray processing of a realistic ice mantle can explain the gas abundances in protoplanetary disks , Proceedings of the National Academy of Sciences (2020/06)