Natasha Hurley-Walker: How radio telescopes show us unseen galaxies
나타샤 헐리 워커(Natasha Hurley-Walker): 전파 망원경이 보여주는 미지의 은하
Natasha Hurley-Walker uses novel radio telescopes to explore the universe at some of the longest wavelengths of light. Full bio
Double-click the English transcript below to play the video.
when I was just six years old,
저는 겨우 여섯 살이었지만
that the universe had to offer.
they took me on a journey,
제 여행이 시작되었습니다.
to become a professional astronomer.
천문학자가 되었습니다.
두 가지를 알게 됐어요.
a starship anytime soon.
없을 거라는 사실이었죠.
is strange, wonderful and vast,
미지의 세계라는 것도 알았습니다.
to be explored by spaceship.
우주선으론 탐험할 수가 없어요.
to astronomy, to using telescopes.
천문학에 관심을 갖게 됐죠.
an image of the night sky.
밤 하늘 사진입니다.
볼 수 있는 모습이죠.
of our local galaxy, the Milky Way.
은하수에 있는 별들입니다.
to a darker part of the sky,
of our Milky Way galaxy
hundreds of billions of stars.
별들이 펼쳐져 있죠.
a local corner of our universe.
극히 일부에 지나지 않습니다.
a sort of strange dark dust across it.
이상하고 어두운 먼지같은 게 있어요.
가려서 잘 안보이죠.
our little corner of the universe.
구석구석을 볼 수 있어요.
like the Hubble Space Telescope.
훌륭한 장비를 이용하면 되죠.
have put together this image.
이름을 붙였습니다.
observing just a tiny patch of the sky
관찰하는 데만 수백 시간이 걸렸죠.
held at arm's length.
엄지손톱 보다도 작은 부분이죠.
hundreds of millions, billions of galaxies
수억, 수십억 개의 은하계가
전혀 다른 모습일 겁니다.
I can continue this journey.
이 과정을 계속 하기만 하면 되겠네.
use a very powerful telescope
하늘을 관찰하면 되지. 문제없네.
if we just do that.
정말 중요한 걸 놓친 거예요.
everything I've talked about so far
just the thing that your eyes can see,
육안으로만 볼 수 있는 것들입니다.
of what the universe has to offer us.
극히 작은 조각에 불과하죠.
problems with using visible light.
두 가지 중대한 문제가 있습니다.
on all the other processes
과정을 무시한다는 것 말고도
that I mentioned earlier.
먼지 성운이에요.
from getting to us.
into the universe, we see less light.
할수록 빛이 옅어지죠.
차단하기 때문입니다.
with using visible light
a busy street corner.
서 있다고 가정해보죠.
점점 멀어짐에 따라서
the siren just to mess with you.
사이렌 소리를 바꾼 건 아닐 거예요.
만들어 낸 결과입니다.
as the ambulance approached,
소리 파동이 압축되면서
the sound waves were stretched,
소리 파동이 늘어지고
and they appear bluer.
더 파랗게 보이고
and they appear redder.
더 붉게 나타납니다.
blueshift and redshift.
from everything else,
멀어지고 있습니다.
everything appears to be red.
나타나고 있다는 뜻이죠.
more deeply into the universe,
are moving away further and faster,
더 빠르게 멀어져요.
to peer deeply into the universe
더 깊은 우주를 관찰하려 했습니다.
어느 순간부터는
거기에서 끝나버리겠죠.
you know, before the redshift kicks in.
눈에 보이는 무언이건 말이죠.
using this for decades.
사용한 기술입니다.
affectionately known as "The Dish."
팍스 전파 망원경을 보여드릴게요.
관찰할 수 있으니까요.
어느 정도 해결됐습니다.
that receive across a large band.
to the center of the Milky Way?
은하를 보면 무엇이 보일까요?
문제 되지 않아요.
straight through dust, so not a problem.
먼지 성운을 뚫고 지나가니까요.
of the Milky Way is aglow,
빛나는 걸 볼 수 있습니다.
synchrotron radiation,
복사광이라고 하는데요.
spiraling around cosmic magnetic fields.
전자들로 구성되어 있습니다.
strange tufts coming off of it,
같은 것이 나와 있는데요.
with our own eyes.
interpret this image,
정말 어렵습니다.
it's very low resolution.
너무 길기때문에
what is the color of everything in here.
구분하기도 어렵습니다.
of the Murchison Radio Observatory,
머치슨 전파 관측소인데요.
to build radio telescopes.
전파 제한구역이라는 점입니다.
아무것도 없죠.
to build a radio telescope.
완벽한 장소라 할 수 있죠.
working on for a few years
a little time lapse of it being built.
and postgraduate students
대학원생들로 구성된 그룹인데요.
학생 군인이라고 부릅니다.
to build a radio telescope.
전파 망원경 건설에 참여했습니다.
these radio dipoles.
조립하고 있는 모습입니다.
a bit like your FM radio or your TV.
낮은 주파수를 수신하기 때문에
across the desert.
covers 10 square kilometers
최종 건설된 망원경의 면적은
there's no moving parts.
부품이 없다는 거예요.
케이블을 통해 전달됩니다.
to central processing units.
over the entire desert
resolution than Parkes.
화질을 얻을 수 있습니다.
bring them to a unit
신호들을 한데 모아서
to a supercomputer here in Perth,
very interesting data
자료들을 분석했습니다.
측정된 자료를 보정하고
on supercomputers
of the entire southern sky,
전체를 관측했습니다.
All-sky MWA Survey,
머치슨 전파 망원경 관측이라고 하고
but it hasn't been shown yet,
아직 공개되지는 않았습니다.
of the entire sky.
보게 되는 거예요.
some images from this survey.
보여드릴 수 있어 정말 기쁩니다.
있다고 상상해보세요.
is no longer dark with dust.
our nearest galactic neighbor,
제일 가까운 은하계죠.
of its more familiar blue-white.
주황색으로 나타납니다.
Let's take a closer look.
좀 더 자세히 볼까요.
towards the galactic center,
that I showed you earlier,
has gone up by a factor of a hundred.
화질로 볼 수 있습니다.
the lowest frequencies red
tell us about the physical processes
우주 안에서 진행되고 있는
along the plane of the galaxy,
we see little blue dots.
파란색 점들이 보일 거예요.
is that they block the red light,
about these star-forming regions
별이 형성되는 영역을 알 수 있어요.
and the color tells us that they're there.
구분할 수 있습니다.
around the galactic plane,
은하계 주변에 있어요.
gathering up material,
mystery to astronomers
오랫동안 학자들 사이에서
of high-energy electrons in the plane
싱크로트론 복사광을 방출한다는 건
radiation that we see,
by supernova remnants,
만들어진다고 추측하고 있는데
good at detecting supernova remnants,
찾아내는 데에 정말 유용합니다.
a new paper out on that soon.
발표되기를 기대하고 있죠.
연구하고 있지만
I wanted to go further.
연구하고 싶었습니다.
interesting object in the top right,
흥미로운 게 있는데요.
센타우루스 A 은하입니다.
two huge plumes going out into space.
밖으로 향하고 있습니다.
between those two plumes,
먼지 통로로 있습니다.
are only visible in the radio.
통해서만 볼 수 있습니다.
we wouldn't even know they were there,
이런 게 있다는 것도 모를 거예요.
than the host galaxy.
크기가 수천 배나 더 큽니다.
What's producing these jets?
왜 이런 분출 형태가 생긴 걸까요?
that we know about
That's why they're called that.
그래서 블랙홀이라고 부르는 거죠.
of the light around them,
그 주변을 굴절하는 빛뿐입니다.
or a cloud of gas comes into their orbit,
이 궤도로 빨려 들어갑니다.
glows brightly in the x-rays,
can launch the material into space
우주 밖으로 내뿜습니다.
전파를 통해서만 볼 수 있습니다.
one radio galaxy. That's nice.
정말 멋지죠.
at the top of that image,
and that's just because it's further away.
black hole at its center
at nearly the speed of light.
밖으로 내뿜고 있죠.
than what I've shown here.
보여드린 것 보다 더 큰데요.
the full extent of the survey,
of these radio galaxies.
있음을 알 수 있습니다.
supermassive black holes.
and it will be published next week.
다음 주에 발표할 예정이에요.
of the galaxy with this survey,
관측해 왔는데요.
even more in this image.
사진 이상의 의미가 있어요.
to the dawn of time.
it was a big bang,
큰 폭발이 있었습니다.
as a sea of hydrogen,
수소로 가득 차게 되었죠.
and galaxies switched on,
형성되기 시작하면서
from neutral to ionized.
이온화 상태가 되었습니다.
그 신호를 새겨두었죠.
오래전에 일어났기 때문에
is at very low frequencies.
낮은 주파수를 갖습니다.
동일한 주파수 대역이지만
of any of the objects in my survey.
10억 분의 1 정도에 불과했죠.
sensitive enough to pick up this signal.
신호를 잡기가 거의 불가능했습니다.
전파 망원경을 보유하게 될 거예요.
radio telescopes in the world.
a new radio telescope,
전파 망원경을 건설 중이에요.
times bigger than the MWA,
수천 배나 더 큰 망원경이죠.
and have an even better resolution.
화질도 훨씬 개선될 것입니다.
tens of millions of galaxies.
은하계를 더 발견하게 되겠죠.
stars and galaxies switching on,
은하를 발견하고
ABOUT THE SPEAKER
Natasha Hurley-Walker - AstronomerNatasha Hurley-Walker uses novel radio telescopes to explore the universe at some of the longest wavelengths of light.
Why you should listen
Dr. Natasha Hurley-Walker recently completed an astronomical survey of the entire southern sky, revealing the radio glow of our own Milky Way galaxy as well as hundreds of thousands of distant galaxies: the GaLactic and Extragalactic All-sky Murchison Widefield Array (GLEAM) survey. Unlike previous work, GLEAM is the first "radio color" survey, observed across such a wide range of frequencies that the unique spectrum of every object can be used to understand its underlying physics.
An Early-Career Research Fellow based at the Curtin University node of the International Centre for Radio Astronomy Research, in Perth, Western Australia, Hurley-Walker is part of the international Murchison Widefield Array (MWA) collaboration, spanning thirteen institutes across six countries. At her fingertips are tens of petabytes of data collected by the MWA since 2013, which she processes using powerful supercomputers at the nearby Pawsey Centre. Hurley-Walker earned a PhD in Radio Astronomy at the University of Cambridge by commissioning and using a new radio telescope to perform its first science observations. The experience directly transferred to the MWA, which she also helped to commission.
The MWA is a precursor to the Square Kilometer Array (SKA), what will be the largest radio telescope in the world, set to come online in the 2020s. By developing software and techniques to deal with data from the MWA, creating pathfinding maps of the sky and training a new generation of astronomers in cutting-edge techniques, Hurley-Walker is working to lay the scientific groundwork for the commissioning of the SKA. In 2016 Hurley-Walker was awarded an Australian SKA Fellowship in order to visit the SKA headquarters and transfer lessons from her commissioning experiences as well as develop her survey into a useful calibration model for the SKA.
Hurley-Walker is passionate about scientific outreach and keynoted talks in 2013 and 2017 at Astrofest, Australia's largest public astronomy festival. So that anyone in the world can see the sky with the same radio eyes as her, she created the GLEAMoscope , an interactive online viewer that shows the universe at radio wavelengths compared to other frequencies, including the more familiar "optical" spectrum. It being the 21st century, there's also an app: check out GLEAM on the Google Play store. In 2017 Natasha won the "Best Timelapse" category in the Astofest astrophotography competition with her colleague John Goldsmith for their creation of a composite video showing both the optical and radio sky. For more detail on Hurley-Walker's work, check out her article on TheConversation.
Working with cutting-edge data is tough, but sometimes hides serendipitous gems which Hurley-Walker has unearthed, like the faintest dying radio galaxy ever discovered, whistling plasma ducts in the Earth's ionosphere and some of the youngest and weirdest radio galaxies ever found. View a complete list of Hurley-Walker's publications.
Natasha Hurley-Walker | Speaker | TED.com