A rare galaxy that's challenging our understanding of the universe | Burçin Mutlu-Pakdil

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2018-09-18 ・ TED


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A rare galaxy that's challenging our understanding of the universe | Burçin Mutlu-Pakdil

661,508 views ・ 2018-09-18

TED


Please double-click on the English subtitles below to play the video.

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There are more than a trillion galaxies in the universe.
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And my team discovered an extremely rare one,
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a galaxy that doesn't look quite like anything observed before.
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This galaxy is so peculiar,
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that it challenges our theories and our assumptions
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about how the universe works.
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The majority of the galaxies are spiral,
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similar to our own Milky Way.
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We have strong theories about how these common galaxies form and evolve.
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But we don't understand how rare galaxies form and evolve.
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An especially puzzling rare case is Hoag's Object.
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It has a very symmetric central body surrounded by a circular outer ring,
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with nothing visible connecting them.
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Hoag-type galaxies are among the rarest types of galaxies currently known.
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There are fewer than one in 1,000 galaxies.
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It's a mystery how the stars in the outer ring are just floating there
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in such an orderly manner.
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That's interesting, right?
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Hold on.
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Things are about to get more mysterious.
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The galaxy that my team discovered is even rarer
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and much more complex than that.
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You know, sometimes, you search and search for these objects,
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and you find nothing.
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But sometimes, it just appears in the background,
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when you are not even looking for it.
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This system looks very similar to Hoag's Object,
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with its central body and circular outer ring.
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We got very excited and thought we discovered another Hoag's Object.
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But my research showed this is an entirely new galaxy type,
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now commonly referred to as "Burçin's Galaxy."
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(Laughs)
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(Cheers) (Applause)
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We will not be visiting this galaxy anytime soon.
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It is approximately 359 million light years away from Earth.
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You may think this is far.
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Well, actually, this is one of the nearby galaxies.
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I study this object in different light --
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in ultraviolet, optical and near-infrared.
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Small details on our body, like a scar or wrinkles,
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tell the story of our lives.
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Similarly, a galaxy's structure in different light
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can help us trace back their origin and evolution.
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How do I look for these details?
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I model the bright central body
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and remove my model from the image
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to check for any hidden features,
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because a bright structure in a galaxy may blind our views of faint features,
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just like using sunglasses when you are blinded by the intense light.
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The result was a big surprise.
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This galaxy doesn't just have an outer ring,
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it has an additional, diffused inner ring.
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We were having a hard time explaining the origin of the outer ring
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in Hoag-type galaxies.
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Now we also need to explain this mysterious second ring.
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There is currently no known mechanism
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that can explain the existence of an inner ring in such a peculiar galaxy.
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So the discovery of Burçin's Galaxy clearly highlights the gap
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in our knowledge of galaxy evolution.
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Further research into how this extremely rare galaxy was formed
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can provide us with new clues on how the universe works.
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This discovery tells us that we still have a lot to learn,
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and we should keep looking deeper and deeper in space
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and keep searching for the unknown.
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Thank you.
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(Applause)
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