Madrid, 27 years old. (Europe Press) –
Observations with the Chinese LAMOST telescope revealed 106 stars in the arc current. Remnants of a dwarf galaxy of the same name have accumulated in the Milky Way.
This typical star currentThe most prominent around the Milky Way– It has been studied extensively by astronomers, as it can be used to limit the galaxy’s potential and help us restore the history of the merger between the dwarf galaxy Sagittarius and the Milky Way, “he said It is a statement Professor ZHAO Jingkun, of the National Astronomical Observatories of the Chinese Academy of Sciences (NAOC) and first author of the work.
“To date, most studies on the current arc focus mainly on its universal characteristics. However, in our work, we investigated the current in the two local LaCoSSPAr regions in detail. LaCoSSPAr (LAMOST Full Spectral Scanning of the Pointing Area) is a LAMOST scan centered on the galaxy’s southern cap.
By combining the radial velocities of LAMOST (Large Sky Area Multibody Spectrophotometry Telescope) and Gaia’s appropriate movements, Researchers have identified 106 reliable Sagittarius stars. The results of the alpha-abundance pattern analysis indicated that the chemical evolution of the current ancestor, the dwarf Sagittarius galaxy, was likely slower than the Milky Way.
Moreover, the different positions of the two regions in the orbit of the current allowed the metallic gradient to be studied, The researchers found that the metallicity slowly varies along the orbit of the current.
“The two regions in the southern galactic cover look like magnifiers,” said Professor WU Hong, LaCoSSPAr planner. “It provides two small windows that illustrate the local characteristics of the arc current and are of great importance in understanding the evolution of this arc.”
The study has been published in The Astrophysical Journal.