9 papers · 1 filter
Anharmonic Infrared Emission of Cyano-Substituted Polycyclic Aromatic Hydrocarbon Molecules: Cyanonaphthalenes as a Case Study
Tao Chen, Kaijun Li, Aigen Li
Recent detections of cyano-substituted polycyclic aromatic hydrocarbons (cyano-PAHs) highlight them as key tracers of nitrogen heterocycles in the interstellar medium (ISM). Howeve…
Widespread Detection of Aromatic and Aliphatic Emission in the Dual Quasar J0749+2255 at Cosmic Noon
C. E. Mentzer, Aigen Li, X. J. Yang
Based on JWST/MIRI integral field observations, we report a widespread detection of aromatic and aliphatic hydrocarbon emission at rest-frame 3.3 and 3.4 micron in SDSSJ074922.96+2…
On the Interstellar Extinction Curve toward HD 93222, A Sightline with an Exceedingly Narrow 2175 Angstrom Extinction Bump
Qian Wang, Aigen Li, Xuejuan Yang
The 2175 Angstrom extinction bump, the most prominent spectral feature superimposed on the interstellar extinction curve, is widely seen in the interstellar medium (ISM) of the Mil…
Unveiling the Aromatic and Aliphatic Universe at Redshifts 0.2--0.5 with JWST NIRCam/WFSS
Jianwei Lyu, Xuejuan Yang, Aigen Li +4
Utilizing deep NIRCam/WFSS data from JWST's FRESCO program, we spectroscopically survey the 3.3 aromatic and 3.4 aliphatic C--H stretching emission bands of polycyclic…
Deuterated Polycyclic Aromatic Hydrocarbons in the Interstellar Medium: Constraints from the Orion Bar as Observed by the James Webb Space Telescope
Xuejuan Yang, Aigen Li
The gas-phase abundances of deuterium (D) in the local interstellar medium (ISM) exhibit considerable regional variations. Particularly, in some regions the gas-phase D abundances…
Polycyclic Aromatic Hydrocarbon and the Ultraviolet Extinction Bump at the Cosmic Dawn
Qi Lin, Xuejuan Yang, Aigen Li +1
First detected in 1965, the mysterious ultraviolet (UV) extinction bump at 2175 Angstrom is the most prominent spectroscopic feature superimposed on the interstellar extinction cur…