Chemical traces in the atmosphere of stars are used to uncover new information about a galaxy, known as Gaia sausage, which was involved in a major collision with the milky roads billions of years ago.
Astrophysicists at Birmingham University in collaboration with colleagues in European institutions in Aarhus, Bologna and Trieste have studied evidence of the star's chemical composition in this area of the Milky Way to try to clarify the age of smaller galaxies.
Gaia's sausage was identified last year by an international team using information from the European Space Agency's Gaia satellite. Its fusion with the Milky Way, which is estimated to have occurred about 1
Only use the information on the chemical traces of Gaia Pølse stars coming from the international APOGEE astronomical study, Birmingham researchers have clarified the age of the galaxies more precisely. By developing detailed models for the production or nucleosynthesis of chemical elements of all kinds of stars and supernovae in the cosmos, they estimate that the sausage was formed around 12.5 billion. Years ago – 2.5 billion Years older than suggested by previous estimates.
Elements interact with light in different ways and by studying the light characteristics of the stars, we can deduce the chemical composition of these stars, "explains Fiorenzo Vincenzo, in Physics and Astronomy at Birmingham University. 19659005]" All chemical elements heavier than helium is produced by stars via thermonuclear burning deep in the heart of the star. Various chemical elements are typically synthesized by different kinds of stars in the cosmos. Oxygen atoms that are so important to life processes, for example, were deposited in the interstellar medium by many successive generations of massive stars until incorporated by our planet about 4.5 billion years ago. We can measure clocks the relative proportion of different chemical traces in the atmosphere of stars and use this measurement as a clock to determine their age. "
Precise star computing is a complex process, and the technique used by the Birmingham team provides a piece of the puzzle. The next step will be to cross the reference to the chemical data with evidence from other techniques, such as study the relative velocities at which stars move – a project that is also underway at Birmingham University.
The merger of the two galaxies seems to have produced another effect as well. The team discovered a gap in the age distribution of stars in The winter road that took place at the same time as the merger, suggesting that the collision caused a break in the star formation within the Winter Road. the formation of stars at this time, "says Dr. Vincenzo." But to confirm this we would need even more accurate measurements of the stars in the stars of the winter street and in the smaller galaxy. "
The study was published in Monthly Messages by the Royal Astronomical Society and is part of the Asterochronometry project funded by the European Research Council and led by Birmingham University. The main purpose of the project is to determine precise and precise star ages – a keystone for understanding our galaxy's collection history.
In this study, the team focused on the chemical traces left by three elements – iron, silicon and magnesium. The next step will be to incorporate measurements from other elements to create a more accurate image.
Chemical documentation shows how a dwarf galaxy contributes to the growth of the Milky Way
Fiorenzo Vincenzo et al. The case of a Giant. Chemical Development of Enceladus, aka Gaia Sausage, Monthly Messages by the Royal Astronomical Society: Letters (2019). DOI: 10.1093 / mnrasl / slz070
Chemistry of stars throws new light on Gaia sausage (2019, May 23)
May 23, 2019
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