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Principale » Hubble captures image of 'hidden galaxy'

Hubble captures image of 'hidden galaxy'

08 Juillet 2017

The James Webb Space Telescope is set to be the largest space telescope ever built. Teasing out finer details requires clever thinking and a little help from a cosmic alignment with a gravitational lens.

In this Hubble photograph of a distant galaxy cluster, a spotty blue arc stands out against a background of red galaxies. That arc is actually three separate images of the same background galaxy. The galaxy has been gravitationally lensed, its light magnified and distorted by the intervening galaxy cluster. On the right: How the galaxy would look to Hubble without distortions.

"When we saw the reconstructed image we said, 'Wow, it looks like fireworks are going off everywhere, '" said Goddard astronomer Jane Rigby to phys.org.

The galaxy in question is so far away that we see it as it appeared 11 billion years ago, only 2.7 billion years after the big bang. Given the distance, despite its impressive powers of observation, even NASA's Hubble Space Telescope needed help in seeing these stars, and this help came from both natural gravitational lensing and human-made computer code.

As a result, the distant galaxy is 30 times brighter than it would normally be - but its light is also distorted and confused, making it hard to image. 2017. Star Formation at z=2.481 in the Lensed Galaxy SDSS J1110+6459: Star Formation down to 30 parsec scales.

The image of the galaxy, which was reconstructed, showed two dozen clumps of newborn stars, each spanning about 200 to 300 light-years.

A new computational technique developed by Traci Johnson, a doctoral candidate at the University of MI and lead author on two of the three papers, helped researchers figure out how the galaxy was warped and undo it.

Without gravitational lensing, the galaxy would appear 'perfectly smooth and unremarkable, ' in the observations, according to the researcher.

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"This would give astronomers a very different picture of where stars are forming".

While Hubble highlighted new stars within the lensed galaxy, NASA's James Webb Space Telescope will uncover older, redder stars that formed even earlier in the galaxy's history.

"The gravity from all that mass has distorted the image that we see of the background galaxy", like a telescope or a "funhouse mirror", Rigby tells Newsweek, explaining that it's an effect that Albert Einstein predicted and that has been proven over and over again since.

These findings appear in a paper published in The Astrophysical Journal Letters and two additional papers published in The Astrophysical Journal.

This artist's illustration portrays what the gravitationally lensed galaxy SGAS 1110 might look like up close.

A lovely mixture of hot, blue star-forming regions, redder, cooler regions of gas, and dark lanes of opaque dust can be seen, all swirling together around a bright core, which astronomers confirmed in 2003, to be a specific type of central region known as an HII nucleus - a name that indicates the presence of ionized hydrogen - that is likely to be creating many hot new stars.

The Hubble Space Telescope is a project of worldwide cooperation between NASA and the European Space Agency. The patches' signature glow comes from ionized hydrogen, like we see in the Orion Nebula in our own galaxy. NASA's Goddard Space Flight Center in Greenbelt, Maryland, manages the telescope. STScI is operated for NASA by the Association of Universities for Research in Astronomy in Washington, D.C.

Hubble captures image of 'hidden galaxy'