Transcript PSCWest Orientation - GBT

Welcome to the Pulsar Search
Collaboratory (PSC) – West!
NRAO
University Wisconsin – Milwaukee
West Virginia University
Yerkes Observatory
University of Chicago
A few words of welcome by . . .
• Dr. Kyle Cudworth
• Mr . . .(Sherry’s principal)
• Vivian Hoette
Pretests
• The NSF grant likes to have data of before and
after – so we have two(?) more short tests to
take before we start!
Let’s introduce ourselves to each
other. . .
Intro to project . . .
Citizen Scientists
• So much of scientific research today relies on the
analysis of incredible amounts of data.
• Scientists cannot possibly look at it all
– Computers do most, but human element is an
essential ingredient, as it always will be
• We already see some “citizen scientists” at work
– Galaxy Zoo
– Einstein at Home
– Other “Zoo” type things
• Educational outreach is also an important part
of any scientist’s request for grant money
– Involving high school, and even middle school
students is highly desirable
• Can undo stereotypes
• Can ignite the interest in science
• Can make science accessible to underserved students
(and to under achievers)
– Involving science teachers is also a plus!
This opportunity . . .
• National Radio Astronomy Observatory in
Green Bank, West Virginia (NRAO)
• University of Wisconsin – Milwaukee (UWM)
• West Virginia University (Morgantown)
Some of the people involved . .
Sue Ann Heatherly
Education Director,
NRAO
Maura McLughlin,
Astronomer, WVU
Rachel Rosen
Astronomer,
Program Director of
PSC
Duncan Lorimer
Astronomer, WVU
From UWM
Xavier Siemens , Physicist, UWM
Larry Price, postdoc, UWM
Jean Creighton, Planetarium Director
ARCC@UWM
research program
• ARCC stands for Arecibo Remote Command
Center
• UWM can also remotely control the GBT
More about this next time!
The group of teachers Sherry and I
worked with summer 2009
Students at last May’s Capstone at
WVU
So let’s see how you can get your
students involved . . .
Astronomy!
• It can really grab the interest of kids,
• They like to ask the big questions:
– What’s out there?
– How do we know?
– Are there Aliens?
• Here is a way you can involve a student of
any ability.
• -Sherry and Kathy’s stories
What is radio
astronomy?
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The Visible Sky, Sagittarius Region
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The
Radio
Sky
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Radio Astronomy is a relatively young
science
Pioneer of Radio Astronomy
Karl Jansky
1928: Karl Jansky, working for Bell Laboratories discovers radio
waves coming from space.
Pioneer of Radio Astronomy
Grote Reber
First Surveys of the
Radio Sky
Chart recordings from Reber's
telescope made in 1943.
In 1967, Cambridge graduate
student
Jocelyn Bell was using a radio
array to study interplanetary
scintillation – SURPRISE!
For this project . .
• Radio data is collected from the
telescopes
• The data is screened by a computer
to a certain point
–Then a human must look at it to see if
it is worth a follow up
• This is where students come in!
• The data is
being
looked at
to find
pulsars –
spinning,
neutron
stars
–Pulsars signals are used to find
gravitational waves.
–Pulsars are used to study
interstellar space.
–Pulsars are inherently interesting in
themselves!
First, some background information . .
.
• The pulsar story will be told by
our astronomers next time
• We will look at and review the
electromagnetic spectrum,
frequency, period, etc.
How do we know about the Universe?
• Everything we know
about the universe
comes to us in the form
of electromagnetic
waves.
• Visible wavelengths are
a very small part of the
electromagnetic
spectrum.
But there is so much more to “see”!
The electromagnetic spectrum
provides much information
Electromagnetic radiation
 A traveling, massless packet of energy --OR an oscillating electric
and magnetic field
 Also known as: radiation, light wave, photon
Travels at the speed of
light (by definition).
Remarkably, all radiation
travels at this speed,
regardless of whether is
carries a lot of energy or
only a little
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Animation from Nick
Strobel’s Astronomy Notes
(www.astronomynotes.com)
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A light wave is a light wave, no matter how
long...
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Frequency:
• How fast something must oscillate to produce
the wave
• The range of radio frequency is
• What is audio frequency? How is it different
from radio frequencies?
Radio Waves are NOT sound!
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Activity Time!
• (Stations set up with different em things to
do)
• (or should we do frequency versus period type
activity? Or both?)
The different parts of the spectrum
provide us with more information
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Jupiter in visible light . . .
Can you imagine “seeing” it in radio?
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Optical and Radio can be done from the ground!
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Radio waves can be detected night or
day
• They also can travel through dust and gas
• So we can see further into our galaxy with
radio waves than with light waves.
Let’s look at a radio telescope
Radio Telescope
Optical Telescope
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Nowadays, there are more
similarities between
optical and radio
telescopes than ever
before.
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At 100 m, the GBT is the largest fully steerable telescope (and the largest movable
structure) in the world..
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The Advantage of Unblocked Optics
Arecibo
Telescope
We will look at a smaller version!
• Itty Bitty telescope
• Radio Jove
• Let’s go outside . . . .
Next: What emits radio
waves?
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Recipe for Radio Waves
1. Hot Gases
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Electron accelerates as it passes near a proton.
EM waves are released
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Recipe for Radio Waves
2. Atomic and molecular transitions
(spectral lines)
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Gas Spectra
Neon
Sodium
434 nm
656 nm
486 nm
Hydrogen
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Electron accelerates to a lower energy state
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Doppler Shift
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Recipe for Radio Waves
3. Electrons and magnetic fields
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Electrons accelerate around magnetic field lines
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The radio telescope and a pulsar
A pulsar is the collapsed core of a
massive star
• It is like taking the mass
of the sun and making it
into a ball the size of
Milwaukee.
• It spins very fast, like an
ice skater who has
brought their arms in.
Why do they pulse?
rotation axis
beam of
radio waves
magnetic field
• Pulsars sweep their
beam of radio
(electromagnetic)
waves across the
face of the earth at
a very periodic rate.
What do the telescopes “see”?
Back to the telescopes:
• The basic question:
• Is it a Pulsar?
– Or is it Radio Frequency Interference (RFI)?
Process . . .
• A computer program analyzes the data for
possible candidates
• A “viewer” page is produced
• Ratings are made and submitted
• Potential pulsars are followed up with
additional observations
• This is what we will learn next time!
Let’s visit the GBT control room . .