University of Barcelona | 2019 May 08
Data from the Gaia satellite, combined with the existent models in our galaxy, allow researchers to find out the rhythm at which the stars that create the disc in the Milky Way have been formed. The impact of our galaxy with a satellite galaxy could be the cause of the creation of more than 50% of the stars in the galactic disc.
A team led by researchers ... have found, analysing data from the Gaia satellite, that a severe star formation burst occurred in the Milky Way about to and three thousand million years ago. In this process, more than 50 % of the stars that created the galactic disc may have been born. There results come from the combination of the distances, colors and magnitude of the stars that were measured by Gaia with models that predict their distribution in our Galaxy. ...
- The region of the stellar formation Rho Ophiuchi observed by ESA Gaia satellite. The shining dots are stellar clusters with the massive and youngest stars of the region. The dark filaments track the gas and dust distribution, where the new stars are born. This is not a conventional photographic image but the result of the integration of all the received radiation by the satellite during the 22 months of continuous measurements through different filters on the spacecraft. Credit: ESA/Gaia/DPAC
Just like a flame fades when there is no gas in the cylinder, the rhythm of the stellar formation in the Milky Way, fuelled by the gas that was deposited, should decrease slowly and in a continuous way until using up the existing gas. The results of the study show that, although this was the process that took place over the first 4,000 million years of the disc formation, a severe star formation burst, or “stellar baby boom” –as stated in the article published in the Nature Research Highlights-, inverted this trend. The merging with a satellite galaxy of the Milky Way, which is rich in gas, could have administrated new fuel and reactivate the process of stellar formation, in a similar way to when a gas cylinder is changed. This mechanism would explain the distribution of distances, ages and masses that are estimated from the data taken from the European Space Agency Gaia satellite. ...
Cosmologic models predict our galaxy would have been growing due the merging with other galaxies, a fact that has been stated by other studies using Gaia data. One of these merges could be the cause of the severe star formation burst that was detected in this study. ...
Gaia DR2 reveals a star formation burst in the disc 2-3 Gyr ago ~ R. Mor et al
- Astronomy & Astrophysics 624:L1 (Apr 2019) DOI: 10.1051/0004-6361/201935105
- arXiv.org > astro-ph > arXiv:1901.07564 > 22 Jan 2019 (v1), 22 Mar 2019 (v4)