Saturday, July 22, 2023

4100 - WEBB TELESCOPE - sees most distant galaxy?

 

-    4100  -   WEBB TELESCOPE  -  sees most distant galaxy?      As astronomers push our views of the Universe further back in time, their telescopes keep uncovering surprises. That’s the case with a supermassive black hole in CEERS 1019, a distant very early galaxy.


--------------  4100  -   WEBB TELESCOPE  -  sees most distant galaxy? 

-    CEERS 1019 galaxy already existed and was assembling itself some 570 million years after the Big Bang. The James Webb Space Telescope (JWST) caught a glimpse of it and studied its black hole. It also took data about two other black holes as they were when the Universe was about a billion years old.

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-    These galaxy and black hole discoveries are part of a special observing program, called the “Cosmic Evolution Early Release Science” (CEERS) Survey. The idea is to get detailed images and spectra of early, distant objects in infrared and mid-infrared light.

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-    Objects in the very early universe shine in ultraviolet and visible light. However, by the time their light reaches us, it’s “stretched” into the infrared region. Since infrared also can penetrate through dusty regions, it gives the added advantage of seeing objects that otherwise would be hidden by the dust.

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-    Finding black holes in the early universe in early galaxies opens up our understanding of that time in cosmic history. It is shortly after the Big Bang.  This newly found CEERS galaxy and its active supermassive black hole surprised astronomers.

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-    CEERS 1019 existed at a time when the first galaxies were forming. So, they should be small and relatively featureless.   And, if they have black holes at that early epoch, those should be relatively low-mass?

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-   It turns out that those black holes are lower-mass. But, at least one of them is still larger than it should be. How do we know this? JWST can study both early galaxies and their black holes.    Not only can we see black holes and galaxies at extreme distances, we can now start to accurately measure them.

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-    The black hole, within galaxy CEERS 1019, existed just over 570 million years after the big bang and is far less massive than other black holes previously found in the early universe.

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-   The galaxy itself appears as three bright clumps without a disk. So, it’s really still assembling itself and cranking out new stars as it builds its structure. A galaxy merger could be partly responsible for fueling the activity in this galaxy’s black hole, and that could also lead to increased star formation.

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-    The infant supermassive black hole is ingesting gas and turns out to have 9 million solar masses. That’s less than some black holes of its era but still larger than expected. It exists so early in history that it seems to have formed very shortly after the Universe began.

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-    The black hole turns out to be more like Sagittarius A*, the one in the center of the Milky Way.   While the infrared view shows us the structure of the galaxy, the spectral lines reveal other characteristics.  Spectra can pinpoint high-energy outflow speeds and temperatures.

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-     The spectroscope captures both the black hole and its host galaxy. Its data reveal the black hole’s appetite for gas as well as the star-formation rate.   These first discoveries are priming astronomers to refine their ideas about black holes and galaxy formation in the infant universe.

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-    The “epoch of reionization” was when light from the first stars could travel through the infant universe. At this time, galaxies began assembling, as did black holes.

The epoch of reionization was when light from the first stars could travel through the infant universe. At this time, galaxies began assembling, as did black holes.

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-    CEERS focuses on these objects as they existed in the Epoch of Reionization, a point in cosmic history when light began to travel freely across the expanding universe. That light came from the first stars and ionized the gas between stars and galaxies.

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-    Galaxies began assembling during this time (and perhaps earlier) as well. The survey data covers the build-up of stars stellar mass, the morphological changes in the galaxies as a result, as well as the growth of those early black holes.

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-    This period is key to tracing a timeline of the Universe’s origins and evolution through the buildup and transformation of those earliest galaxies. This is one of the key aims of the JWST, which is just finishing its first full year of observing the infrared universe, July, 2023.

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July 20,  2023            WEBB TELESCOPE  -  sees most distant galaxy?             4100

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--------------------- ---  Saturday, July 22, 2023  ---------------------------------

 

 

 

 

 

           

 

 

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