ABSTRACT Local Group (LG) very metal-poor massive stars are the best proxy for First Stars of Universe and fundamental to modelling evolution early galaxies. These may follow new evolutionary pathways restricted low metallicities, such as chemically homogeneous (CHE). However, given great distance leap needed reach galaxies LG vicinity, no comprehensive spectroscopic studies have been carried o...

Abstract Metal-deficient stars are important tracers for understanding the early formation of Galaxy. Recent large-scale surveys with both photometric and spectroscopic data have reported an increasing number metal-deficient whose kinematic features consistent those disk stellar populations. We report discovery RR Lyrae variable (hereafter RRL) that is located within thick has orbit thick-disk ...

ABSTRACT The origin of the Lyman α (Lyα) emission in galaxies is a long-standing issue: despite several processes known to originate this line (e.g. active galactic nucleus, star formation, cold accretion, shock heating), it difficult discriminate among these phenomena based on observations. Recent studies have suggested that comparison ultraviolet (UV) and optical properties sources could solv...