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Scientists used a dark energy camera to photograph our “galaxy expansion”



In order to study how the so-called “galactic bulge” formed in the center of the Milky Way, scientists used dark energy cameras to detect parts of the sky and take photos of billions of stars.

The Hubblesite of the National Aeronautics and Space Administration (NASA) describes our galaxy as “shaped like two fried eggs glued back to back.” This painting allows us to clearly see the central bulge of the star located in the middle of the scattered stellar disk usually seen in two-dimensional images. Through the following ESA rendering, you can better understand the appearance:

This makeup is considered a common feature of countless spiral galaxies (such as the Milky Way), and scientists hope to study how the bulge forms. Are the expanding stars born in the history of the Milky Way between 10 to 12 billion years ago, or are they formed by multiple star formations over time?

“Many other spiral galaxies look like the Milky Way and have similar bulges, so if we can understand how the Milky Way forms its bulge, then we will have a good understanding of other galaxies as well,” Researcher Christian said. Johnson of the Space Telescope Science Institute in Baltimore, Maryland.

The team used the Dark Energy Camera (DECam) on the Victor Blanco 4-meter telescope at the Cerro Tololo American Observatory to survey the sky over 200 square meters (about the area of ​​1,000 full moons). In Chile, this is the plan of NSF NOIRLab.

This image shows a wide field of view of the center of the Milky Way galaxy with a pulled-out image taken by DECam.

The scientific sensor array on DECam consists of 62 individual 2048×4096 pixel back-illuminated CCD sensors, totaling 5 20 megapixels. An additional 12 2048×2048 pixel CCD sensors (50 megapixels) are used to guide the telescope, monitor focus and help alignment.

This wide-angle camera was able to capture 3 square degrees of sky in a single exposure and allowed the team to collect more than 450,000 personal photos. Based on these data, the research team was able to determine the chemical composition of millions of stars.The following figure contains Billion Number of stars:

You can view a zoomable and zoomed version of this image here. It uses the same interface as the giant 2.5 megapixel image of Orion Constellation taken by Matt Harbison.

For this particular study, scientists observed a sub-sample of 70,000 stars from the above image. It was previously believed that raised stars were born in two different “waves” early in the history of galaxies, but because of the data collected in this study, scientists now believe that most of them were formed at about the same time Nearly 10 billion years ago.

According to the National Aeronautics and Space Administration, researchers are investigating the possibility of measuring the distance of stars in order to produce more accurate 3D maps of the bumps. They also plan to look for correlations between metallicity measurements and star orbits. This investigation can find “groups” of stars with similar orbits, which may be the broken remains of dwarf galaxies, and can also identify signs of accumulation, such as stars rotating relative to the star.

(Via Hubblesite and SyFy)




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