Galaxy structures are fossil records of their assembly history. Modern IFU spectrographs offer the ability to map the spatial distribution of the motions, ages, and chemical abundances of stars in galaxies, which provide unprecedented detailed view of galaxies structures. But the information are still blended along the line-of-sight. Decomposition of galactic structures in a physical way is challenging, especially for the barred galaxies with complicated combination of a few structures in the center.
We developed an orbit-superposition method for external barred galaxies, which is a first general dynamical model that can fit the bar explicitly in both the morphology and kinematics. By testing with mock data, we find that the key parameters of the galaxy like the bar pattern speed, and the internal stellar orbit distribution, are well uncovered. Then we applied the method to a first real barred galaxy NGC 4371. We find NGC4371 has a slow bar with bar rotation rate R~2.2. We successfully decompose an x-shaped bar, a round classic bulge, an inner disk, an outer disk, and we quantify the light distribution and kinematic properties of each component. Our method opens the way of modeling and physical structure decomposition for a large sample of nearby barred galaxies with IFU observations.
BIO
Dr. Ling Zhu is a research professor in Shanghai Astronomical observatory. She got her phD at Tsinghua university in 2013, then she became a post-doc in the Max Planck institute for Astronomy, and join SHAO in 2018. Her research interests focus on galactic dynamics, dark matter distribution, galaxy structure formation and evolution.
Host: Dandan Xu
