Natasha Hurley-Walker: How radio telescopes show us unseen galaxies
娜塔莎 赫莉-沃克: 射电望远镜是怎样给我们展示肉眼见不到的宇宙的
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,
that the universe had to offer.
they took me on a journey,
我就踏上了追梦旅程
to become a professional astronomer.
a starship anytime soon.
奇妙、壮观、广阔的
is strange, wonderful and vast,
根本不可能探索得完
to be explored by spaceship.
to astronomy, to using telescopes.
用望远镜来探索宇宙
我先给大家展示一下星空吧
an image of the night sky.
都能看到这样的景象
of our local galaxy, the Milky Way.
to a darker part of the sky,
of our Milky Way galaxy
hundreds of billions of stars.
一个局部的中心
a local corner of our universe.
a sort of strange dark dust across it.
探索宇宙的一个小角落
our little corner of the universe.
(来探索宇宙)
like the Hubble Space Telescope.
have put together this image.
收集到的景象放在一起
observing just a tiny patch of the sky
指甲还小的地方
held at arm's length.
hundreds of millions, billions of galaxies
另一些和我们的完全不同
我可以继续研究
I can continue this journey.
足够牛的望远镜就行
use a very powerful telescope
就什么都探索不到了
if we just do that.
everything I've talked about so far
你们的眼睛就可以看到,
just the thing that your eyes can see,
of what the universe has to offer us.
非常重要的问题需要解决
problems with using visible light.
on all the other processes
我们也有两个问题
that I mentioned earlier.
我们看不到后边的东西
from getting to us.
光线就比之前更少
into the universe, we see less light.
with using visible light
喧闹大街的角落,很热闹
a busy street corner.
又远离你的过程中
引起你的注意而改变声调的
the siren just to mess with you.
as the ambulance approached,
the sound waves were stretched,
and they appear bluer.
and they appear redder.
blueshift and redshift.
from everything else,
都在向红移的方向发展
everything appears to be red.
more deeply into the universe,
are moving away further and faster,
to peer deeply into the universe
并不只是我用肉眼看到的
you know, before the redshift kicks in.
using this for decades.
我们亲切的叫它“盘子”
affectionately known as "The Dish."
that receive across a large band.
能够接受穿过岩石的射线
看向宇宙中心的时候
to the center of the Milky Way?
无线电穿过了尘埃,所以问题解决了
straight through dust, so not a problem.
of the Milky Way is aglow,
synchrotron radiation,
spiraling around cosmic magnetic fields.
strange tufts coming off of it,
with our own eyes.
interpret this image,
it's very low resolution.
what is the color of everything in here.
到底是什么颜色的
of the Murchison Radio Observatory,
to build radio telescopes.
to build a radio telescope.
working on for a few years
a little time lapse of it being built.
and postgraduate students
建造这个射电望远镜
to build a radio telescope.
these radio dipoles.
电视一样接收低频信号
a bit like your FM radio or your TV.
across the desert.
covers 10 square kilometers
there's no moving parts.
to central processing units.
over the entire desert
处理问题能力的方面
resolution than Parkes.
bring them to a unit
to a supercomputer here in Perth,
一个超级计算机上
very interesting data
on supercomputers
星空做了一番仔细观察
of the entire southern sky,
All-sky MWA Survey,
广角阵列全天候研究
but it hasn't been shown yet,
但是目前还没有
of the entire sky.
研究中的部分图像
some images from this survey.
is no longer dark with dust.
our nearest galactic neighbor,
of its more familiar blue-white.
让我们放大看一下
Let's take a closer look.
towards the galactic center,
that I showed you earlier,
has gone up by a factor of a hundred.
the lowest frequencies red
tell us about the physical processes
along the plane of the galaxy,
我们会看到蓝色的点
we see little blue dots.
is that they block the red light,
about these star-forming regions
颜色就会告诉我们它们在那儿
and the color tells us that they're there.
around the galactic plane,
聚合其他的物质
gathering up material,
那些超新星残余物的去向
mystery to astronomers
一定有许多高能电子
of high-energy electrons in the plane
radiation that we see,
同步加速器辐射
by supernova remnants,
探测到超新星残余物
good at detecting supernova remnants,
a new paper out on that soon.
这一方面研究成果的产生
I wanted to go further.
一个很有意思的东西
interesting object in the top right,
two huge plumes going out into space.
between those two plumes,
are only visible in the radio.
we wouldn't even know they were there,
根本不知道它们在那里
than the host galaxy.
这些星点是从哪里来的呢
What's producing these jets?
that we know about
That's why they're called that.
这就是为什么叫做黑洞
它们周围改变轨迹的光线
of the light around them,
or a cloud of gas comes into their orbit,
glows brightly in the x-rays,
can launch the material into space
一个电波星系,很不错
one radio galaxy. That's nice.
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.
than what I've shown here.
the full extent of the survey,
of these radio galaxies.
supermassive black holes.
and it will be published next week.
下周研究成果就会公开
of the galaxy with this survey,
even more in this image.
to the dawn of time.
it was a big bang,
as a sea of hydrogen,
and galaxies switched on,
变成了电离的了
from neutral to ionized.
is at very low frequencies.
of any of the objects in my survey.
sensitive enough to pick up this signal.
探索到这些信号
radio telescopes in the world.
一个新的射电望远镜
a new radio telescope,
times bigger than the MWA,
and have an even better resolution.
tens of millions of galaxies.
第一颗星体和星系
stars and galaxies switching on,
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