The 4-m Multi-Object Spectroscopic Telescope (4MOST) is one of the ESO community survey with a large field-of-view to survey the southern sky in a few years, delivering spectra for ≥25 million objects over ≥15 000 square degrees in R~6000 and R~20000. 4MOST is currently in its manufacturing, assembly, integration and test phase with an expected start of full science operations within a year. As the date of first light approaches, the pipelines for galactic and extragalactic sources are also in intense developments. I will introduce parts of the recent process for the 4MOST galactic pipeline (4GP): radial velocity and pysme submodule. These module serve as the main part to determine stellar parameters, and although they can be treated as merely finding the best-match template spectra to the observed ones, the implementation to a survey is not so simple. The correct uncertainty estimation requires a homogeneous set of synthetic spectra in 4MOST format, and we are in a transition period from 1D-LTE to NLTE or even 3D-NLTE template. These submodules, together with other ones in 4GP, will help us extract the information of the 4MOST spectra, and a smoother process for the following science cases.
BIO
Mingjie Jian is currently a postdoctoral researcher at Stockholm University. He obtained his bachelor's degree from Beijing Normal University in 2016 and his PhD from the University of Tokyo in 2022. His research interests lie in stellar radiative transfer, galactic archaeology, and massive stars. As a consortium member of the 4-m Multi-Object Spectroscopic Telescope (4MOST), he is now involved in the development of the stellar parameter pipeline for galactic surveys, aiming to determine stellar parameters for 4MOST targets.
