The European Space Agency has released the third batch of data for the Gaia mission, which contains information about more than 1.8 billion objects in the universe. The stars move towards the anti-center of our Milky Way galaxy, in the opposite direction to the center, which makes it possible to study the past of the Milky Way and its neighboring Sagittarius brush.
After the first period in 2016 and the second period in 2018, a third early data version appeared (The third early data release The European Space Agency’s (ESA) Gaia mission (EDA3) was made public this Thursday. The world astronomy community is full of expectations for this.
The third part: Gaia (Gaia), this is a great astronomical mission in Europe, contains detailed information about more than 1.8 billion sources or objects detected by the detector, compared to the second data launch (Gaia DR2 ), an increase of more than 100 million.
Gaia EDR3 also provides color information from about 1.5 billion sources, an increase of about 200 million from the previous issue. In addition, the overall accuracy and measurement accuracy have also been improved. He reiterated: “Gaia’s new data is expected to become the real wealth of astronomers.” Jos de Bruijne, Is an associate scientist of the ESA Gaia project.
Towards the anti-center of the Milky Way
The new data obtained from this mission makes it possible to study the movement and distribution of older and younger stars towards the boundaries of the Milky Way: anti-center, which is the direction completely opposite to the center of the Milky Way. Looking in this direction, astronomers from the Gaia Data Processing and Analysis Association (DPAC) have discovered clues to the past of the Milky Way.
One of the four “demonstration papers” published with Gaia Data introduced the results of the anti-center. Other studies have used the results in this catalog to provide a huge expansion of the nearby census of stars, derive the shape of the solar system’s orbit around the center of the Milky Way, and study the structure of the two galaxies near the Milky Way.
Computer models predict that with the birth of new stars, the disk of our galaxy will grow over time. The new data allows us to see the remaining amount of disks with a history of 10 billion years to determine the disk coverage that is smaller than the current disk size.
Friction between the Milky Way and Sagittarius
The new information from these outer regions also strengthens the notion that another major event occurred in the recent history of the galaxy. They showed that in the outer region of the disk, a slow-moving star above the plane of the Milky Way descends toward it, and a fast-moving star below the ascending plane.
Up to now, this extraordinary pattern is unpredictable. This may be the result of a quasi-collision between the Milky Way and the dwarf galaxy Sagittarius, which happened in the recent history of our Milky Way.
The dwarf galaxy in Sagittarius contains tens of millions of stars and is being swallowed by the Milky Way. The last time it passed through our Milky Way, it did not completely hit it, although its gravitational force was enough to interfere with some of the stars in the Milky Way, like a rock falling into the water.
Thanks to data from Gaia DR2, DPAC members have discovered subtle fluctuations in the motion of millions of stars, which hints at the impact of the encounter with Sagittarius, which occurred between 30 and 900 million years ago. Now, thanks to EDR3, they have found more clues that it has a powerful effect on the stellar disk of our galaxy.
He said: “The motion of the stars on the disk is different from what we imagined.” Teresa AntojaFrom the University of Barcelona, where various events were organized online (forum, meeting, Memory game) To celebrate the release of Gaia EDR3. The University’s Institute of Space Science (International Criminal Court) Participated in the Gaia mission since its inception.
Antoja and other colleagues at DPAC conducted data analysis. Although the role of Pygmy is still debated in some circles, Teresa claims that it may be “a good candidate for all these disturbances, as some simulations by other authors have shown.”
Measure the orbit of the solar system
The history of the galaxy is not the only result of the EDR3 demo article. DPAC members from all over Europe have done other work to demonstrate the extremely high fidelity of the data and its unique potential in facilitating unlimited scientific discovery.
In another study, scientists used Gaia data to measure the acceleration of the solar system relative to the rest of the universe. Using the observed motion of extremely distant galaxies, the velocity of the solar system is measured to vary 0.23 nm/s per second.
Because of this tiny acceleration, the solar system’s trajectory deviates from the diameter of an atom every second, which is equivalent to about 115 kilometers in a year. The acceleration measured by Gaia is in line with theoretical expectations and provides the first measure of the curvature of the solar system’s orbit around a galaxy in the history of optical astronomy.
New stellar census
Gaia EDR3 also makes it possible for our solar neighborhood to obtain a new census of stars.This Gaia’s Near Star Catalog It contains 331,312 celestial bodies, which is estimated to account for 92% of the stars within 100 pas (326 light years) of the sun.
The last census of solar neighboring countries was called the Gliese Catalog and was compiled in 1957. Initially it contained only 915 objects, but was updated in 1991 to cover 3,803 objects. It is also limited to a distance of 82 light-years, while the Gaia Census is four times the distance and the number of stars is a thousand times. It also provides position, motion, and brightness measurements with an accuracy that is orders of magnitude higher than the old data.
Enter the Magellanic Cloud
The fourth presentation article focuses on the Magellanic Cloud-two galaxies orbiting the Milky Way. After measuring the motion of stars in the Large Magellanic Cloud with unprecedented precision, Gaia EDR3 clearly shows that the galaxy has a spiral structure.
The data also solves the mystery of a group of stars attracted to the outside of the Small Magellanic Cloud and points to previously invisible structures on the boundaries of the two galaxies.
Since December 3, the data generated by scientists and engineers of the Gaia DPAC Alliance has been provided to anyone who wishes to consult and learn from them. This will be the first part of the double throw: Plan to release the third complete data release (DR3) in 2022.
“Gaia EDR3 is the result of the tremendous efforts of everyone involved in the Gaia mission. This is a very rich data set, and I look forward to astronomers around the world using this resource to make many discoveries.” Timo Prusti, ESA’s Gaia project scientist predicts: “This is just the beginning, and more data is waiting for us.”