Natasha Hurley-Walker: How radio telescopes show us unseen galaxies
נטשה הרלי ווקר: איך רדיו טלסקופים מראים לנו גלקסיות בלתי נראות
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,
כשהייתי רק בת שש,
that the universe had to offer.
they took me on a journey,
הן לקחו אותי למסע,
to become a professional astronomer.
a starship anytime soon.
is strange, wonderful and vast,
to be explored by spaceship.
to astronomy, to using telescopes.
לשימוש בטלסקופים.
an image of the night sky.
of our local galaxy, the Milky Way.
מהגלקסיה המקומית שלנו, שביל החלב.
to a darker part of the sky,
לחלק חשוך יותר של השמים,
of our Milky Way galaxy
גלקסית שביל החלב שלנו
hundreds of billions of stars.
a local corner of our universe.
a sort of strange dark dust across it.
סוג של אבק כהה ומוזר לרוחבו.
our little corner of the universe.
את הפינה הקטנה שלנו ביקום.
like the Hubble Space Telescope.
כמו טלסקופ החלל האבל.
have put together this image.
observing just a tiny patch of the sky
רק קטע קטן של השמיים
held at arm's length.
מוחזק במרחק הזרוע.
hundreds of millions, billions of galaxies
מאות מליוני, מיליארדי גלקסיות
I can continue this journey.
אני יכולה להמשיך את המסע הזה.
use a very powerful telescope
בטלסקופ ממש חזק
if we just do that.
everything I've talked about so far
מה שדיברתי עליו עד עכשיו
just the thing that your eyes can see,
רק מה שהעיניים שלכם יכולות לראות,
of what the universe has to offer us.
problems with using visible light.
בשימוש באור נראה.
on all the other processes
את כל התהליכים האחרים
that I mentioned earlier.
from getting to us.
into the universe, we see less light.
אנחנו רואים פחות אור.
with using visible light
a busy street corner.
the siren just to mess with you.
רק כדי לשגע אתכם.
as the ambulance approached,
the sound waves were stretched,
and they appear bluer.
והם מופיעים כחולים יותר.
and they appear redder.
והם נראים אדומים יותר.
blueshift and redshift.
הסטה לכחול והסטה לאדום.
from everything else,
everything appears to be red.
more deeply into the universe,
עמוק יותר לתוך היקום,
are moving away further and faster,
נעים הרחק יותר ומהר יותר,
to peer deeply into the universe
you know, before the redshift kicks in.
לפני שההסטה לאדום פועלת.
using this for decades.
affectionately known as "The Dish."
שנקרא בחיבה "הצלחת."
that receive across a large band.
שקולטים ברוחב פס גדול.
to the center of the Milky Way?
למרכז שביל החלב?
straight through dust, so not a problem.
אז אין בעיה.
of the Milky Way is aglow,
שהמרכז של שביל החלב זוהר,
synchrotron radiation,
spiraling around cosmic magnetic fields.
סביב שדות מגנטיים קוסמיים.
strange tufts coming off of it,
ציציות מוזרות מגיעות ממנו,
with our own eyes.
interpret this image,
it's very low resolution.
זה ברזולוציה ממש נמוכה.
what is the color of everything in here.
מה הצבע של הכל שם בפנים.
of the Murchison Radio Observatory,
של מצפה הכוכבים ברדיו מרצ'יסון,
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
to build a radio telescope.
these radio dipoles.
a bit like your FM radio or your TV.
מעט כמו רדיו ה FM שלכם או הטלוויזיה.
across the desert.
covers 10 square kilometers
there's no moving parts.
to central processing units.
over the entire desert
resolution than Parkes.
bring them to a unit
מביאים אותם ליחידה
to a supercomputer here in Perth,
very interesting data
on supercomputers
of the entire southern sky,
All-sky MWA Survey,
של כל השמיים,
but it hasn't been shown yet,
אבל הוא לא הוצג עדיין,
of the entire sky.
some images from this survey.
כמה תמונות מהסקר הזה.
is no longer dark with dust.
לא חשוך יותר מאבק.
our nearest galactic neighbor,
השכן הגלקטי הקרוב ביותר שלנו,
of its more familiar blue-white.
Let's take a closer look.
בואו נביט מקרוב יותר.
towards the galactic center,
that I showed you earlier,
שהראתי לכם מוקדם יותר,
has gone up by a factor of a hundred.
עלתה בפקטור של מאה.
the lowest frequencies red
את התדירויות הנמוכות באדום
tell us about the physical processes
בנוגע לתהליכים הפיזיקליים
along the plane of the galaxy,
לרוחב המישור הגלקטי של הגלקסיה,
we see little blue dots.
נראה נקודות כחולות קטנות.
is that they block the red light,
about these star-forming regions
על אזורים בהם כוכבים נוצרים
and the color tells us that they're there.
והצבע מספר לנו שהם שם.
around the galactic plane,
gathering up material,
mystery to astronomers
of high-energy electrons in the plane
הרבה אלקטרונים באנרגיה גבוהה במישור
radiation that we see,
שאנחנו רואים,
by supernova remnants,
על ידי שאריות סופר נובה,
good at detecting supernova remnants,
באמת טוב לזיהוי שאריות סופר נובה,
a new paper out on that soon.
I wanted to go further.
רציתי להמשיך הלאה.
interesting object in the top right,
עצם מעניין מימין למעלה,
two huge plumes going out into space.
שתי פלומות גדולות שיוצאות לחלל.
between those two plumes,
are only visible in the radio.
we wouldn't even know they were there,
than the host galaxy.
What's producing these jets?
that we know about
That's why they're called that.
לכן הם נקראים כך.
of the light around them,
את ההסטה של האור סביבם,
or a cloud of gas comes into their orbit,
נכנס למסלול הקפה,
glows brightly in the x-rays,
can launch the material into space
יכולים לשגר את החומר לחלל
one radio galaxy. That's nice.
גלקסיית רדיו אחת, זה נחמד.
at the top of that image,
and that's just because it's further away.
וזה בגלל שהיא מרוחקת יותר.
black hole at its center
at nearly the speed of light.
than what I've shown here.
ממה שהראתי פה.
the full extent of the survey,
of these radio galaxies.
300,000 גלקסיות רדיו כאלו.
supermassive black holes.
הסופר מסיבים הראשונים.
and it will be published next week.
of the galaxy with this survey,
של הגלקסיה בסקר הזה,
even more in this image.
to the dawn of time.
it was a big bang,
as a sea of hydrogen,
and galaxies switched on,
from neutral to ionized.
is at very low frequencies.
of any of the objects in my survey.
sensitive enough to pick up this signal.
לקלוט את האות הזה.
radio telescopes in the world.
a new radio telescope,
רדיו טלסקופ חדש,
times bigger than the MWA,
and have an even better resolution.
אפילו רזולוציה טובה יותר.
tens of millions of galaxies.
עשרות מליוני גלקסיות.
stars and galaxies switching on,
לכוכבים והגלקסיות הראשונים שנדלקו,
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