This project focuses on researching, searching, detecting and evaluating the role of galaxies in the early stages of the universe; researching on the structure, chemical composition and evolution of protoplanetary discs; the role of magnetic fields in star formation; the morphology and dynamics of old stellar shells, and the mechanism of symmetry breaking of globular stars like the Sun to become planetary nebulae with diverse shapes.
Promote basic research, improve research capacity and research training in the field of astrophysics, strengthen the domestic, regional and world position of a strong and unique research group at present in astrophysics, contributing to the successful implementation of the nation’s space science and technology strategy and program.
Main tasks of the project
Task 1: Research the formation of stars and planets
In young multiple star systems, gravitational tidal interactions between the component stars create a cavity of gas and dust that forms twisted arm-like structures that help transport material from the outer binary disk to supply the single disks within and into the center of each component star at the center of the system. In order to determine the gas properties in this cavity and on the double disk, we proposed to use the NOEMA radio interferometry system to observe the distribution of HCO+ and HCN, CS and C2H in the cavity and double disk of the young triple star system GG Tau A. This study is the first step toward characterizing the material that forms S-type planets. Our proposed observation has been evaluated as B-type with 8 hours of interferometric observations. NOEMA radio is expected to provide observational data with a spatial resolution of about 60 au. In addition, a number of other protoplanetary disk systems using ALMA data will also be studied within the framework of this project.
On a larger scale in molecular gas clouds, where new stars form, we will determine the direction and magnitude of the magnetic field in several star-forming regions such as molecular clouds G11, W51, Orion, etc. through polarized emission, especially emission from dust. From there, we will evaluate the relative contributions of the following factors: gravity, magnetic fields, turbulence, and stellar feedback that influence star formation rates; orientation and destruction of dust in star formation regions. In addition, we will also study the dust polarization properties in the protoplanetary disk.
Task 2: Research the morphology and kinematics of old stellar shells
We will study the morphology and dynamics of gas and dust in the shells of some old stars such as RS Cnc, Chi Cygni, SV Psc, R Aql, etc. to find out their general properties, especially the properties in the area near the center of the star. We use high-resolution data at millimeter wavelengths measured by the ALMA observatories in the southern hemisphere and NOEMA in the northern hemisphere. We will also analyze the emission lines of different molecules such as CO, SiO, HCN, SO, SO2 to get a multidimensional picture of the shells of these stars.
Task 3: Formation and evolution of galaxies
At optical wavelengths, we study characteristic star-forming galaxies of the LAE and LBG types behind gravitationally lensed galaxy clusters, observed with the James Webb space telescope, Hubble, and the Very Large Telescope with the MUSE multi-object mass spectrometer. We construct the galactic luminosity distribution function at the faintest limit known. Calculations are done to clarify the ratio of LAE-type galaxy composition to LBG-type galaxy composition, which are two types of galaxies that mainly contribute to the reionization process of the early universe. We also learn some correlations between physical quantities such as star formation rates and the masses of their stellar components, such as the escape rate of Lyman-alpha photons as a function of time in this set of galaxies. In the radio wavelength region, we study a number of gravitational lens galaxies emitting CO molecular gas lines and dust composition to reconstruct their morphology and kinematics. There are a number of lens galaxies observed in both optical (VLT/MUSE) and radio (ALMA) regions. The combination of two data sources from two state-of-the-art instruments will provide complementary information to help clarify the role of key factors in the formation and evolution of galaxies.
