Transcript STIC Director's Report

Hubble Science Briefing
Looking Forward to our
Deepest View of the Universe:
Science with the Near-Infrared Camera on the
James Webb Space Telescope
December 4, 2014
Gerard Kriss
Space Telescope
Science Institute
The James Webb Space Telescope (JWST)
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Who is James E. Webb?
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1906 - 1992
NASA’s Second Administrator
Led the Apollo effort
Implemented the space
science program within NASA
Began proposal efforts for
large space based telescopes
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Bigger is Better!
JWST’s mirror is almost 3 times larger than Hubble’s
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JWST Full Scale Model at NASA
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Where to find JWST
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A gold plated telescope!
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A gold plated telescope!
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What is Infrared Light?
Image Credit: Lawrence Berkeley Lab Microworlds Project
http://www2.lbl.gov/MicroWorlds/ALSTool/EMSpec/EMSpec2.html
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Infrared Light
• Infrared light can see
through some materials
that visible light can’t.
• With an infrared camera,
we can see the heat
from the man’s arm and
hand and “see” through
the black bag.
• Infrared light can also
see through thick smoke
and fog.
• We need infrared light to
see the stars in the most
distant galaxies.
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Infrared Light
• Infrared light can see
through some materials
that visible light can’t
• With an infrared camera,
we can see the heat
from the man’s arm and
hand and “see” through
the black bag.
• Infrared light can also
see through thick smoke
and fog.
• We need infrared light to
see the stars in the most
distant galaxies.
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The Universe is Expanding
Image Credit: Science Blogs, Ethan Siegel
http://scienceblogs.com/startswithabang/2008/02/07/
the-cosmic-microwave-background-not-always/
Image Credit: GSFC HEASARC “Imagine the Universe”
http://imagine.gsfc.nasa.gov/features/yba/M31-velocity/hubble-more.html
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Redshifts and Blueshifts
Scale factor (1+z) tells us how much
the wavelengths have been stretched.
Image Credit: Wikipedia/Aleš Tošovský
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Formation of the First Galaxies
First Galaxies Form
Visible light for these galaxies
is redshifted to infrared wavelengths.
Image Credit: Evolution, a Scientific American Reader
2006, University of Chicago Press
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Four Science Instruments
NIRCam
MIRI
NIRSpec
NIRISS
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Vertical Field Position (arcmin)
Fields of View of JWST Instruments
4
NIRISS
FGS
2
0
-2
NIRCam
NIRSpec
MIRI
-4
-8
-6
-4
-2
0
2
4
Horizontal Field Position (arcmin)
6
8
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NIRCam has Two Imagers in Two Modules
2.2 arcmin
Module B
Module A
Short wavelength channel
Long wavelength channel
2.2 arcmin
2.2 arcmin
Two adjacent fields of view (2.2 arcminute)2
Both fields in SW and LW bands
Two back-to-back modules
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NIRCam Optical Layout
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View of NIRCam’s Optics
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NIRCam with Enclosures
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NIRCam Filter Wheel
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Assembled Modules
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NIRCam: The Near Infrared Camera
 2 functionally identical (mirror image) modules
 2 channels in each module:
Short Wavelength
(0.6-2.3 m)
Long Wavelength
(2.4-5.0 m)
HgCdTe FPA Format
(22)  (2040  2040)
HgCdTe FPA Format
1  (2040  2040)
0.032 arcsec/pixel
0.065 arcsec/pixel
FOV= 2.212.21
arcmin2
FOV= 2.212.21
arcmin2
 5” gap between SW SCAs
 40” gap between A & B
 Filters provide (W  R=4; M  R=10; N R=100)
 LW Grisms provide R~3000
 Sensitivity (S/N=10, R=4, in 104 s):
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1.1 m: 10.4 nJy
2.0 m: 12.1 nJy
4.4 m: 24.5 nJy
 Coronagraphic masks:
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NIRCam Sensitivity Comparison
1000
5-sigma, 50,000 secs
Ground
nJy
100
SST
HST
10
JWST NIRCam
1
0.1
0.5
Galaxy models:
Ground (Keck/VLT)
1.5
2.5
3.5
4.5
Wavelength (m
(Microns)
m)
Space (HST or SPITZER)
NIRCam
z=5.0
z=10.1
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JWST has Four Science Goals
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End of the dark ages: first light and
reionization
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The assembly of galaxies
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Birth of stars and
protoplanetary systems
Planetary systems and
the origins of life
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Galaxies Form as Gas Clouds
Collapse in the Early Universe
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After the Big Bang, gas in the
universe is smoothly distributed, with
slight irregularities that we can see in
the Cosmic Background Radiation.
Image Credit: NASA / WMAP: http://map.gsfc.nasa.gov/media/080997/index.html)
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Gravity causes the densest filaments
and points to collapse.
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These dense knots form the first
stars and galaxies.
Image Credit: Volker Springel, et al. 2004
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End of the dark ages:
first light and reionization
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What are the first galaxies?
What objects reionized the gas between the galaxies?
Key JWST Observations:
• Ultra-Deep Near InfraRed survey
(NIRCam, NIRISS)
• Spectroscopic Near-IR & Mid-IR
confirmation.
(NIRCam & NIRISS Grisms,
NIRSpec, MIRI)
o The red circles show the locations
of faint, red distant galaxies.
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The assembly of galaxies
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Where and when did the Hubble Sequence form?
How did galaxies like the Milky Way take shape?
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Birth of stars and protoplanetary
systems
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How do interstellar clouds
collapse to form stars?
How do gaseous disks form
around stars?
How do planets condense out of
the gaseous disks?
Deeply embedded protostar
Circumstellar disk
The Eagle Nebula
as seen by HST
• Imaging of molecular clouds
• Survey “elephant trunks”
• Survey star-forming clusters
Agglomeration & planetesimals
Mature planetary system
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Birth of stars and protoplanetary
systems
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How do interstellar clouds
collapse to form stars?
How do gaseous disks form
around stars?
How do planets condense out of
the gaseous disks?
Deeply embedded protostar
Circumstellar disk
The Eagle Nebula
as seen in the infrared
• Imaging of molecular clouds
• Survey “elephant trunks”
• Survey star-forming clusters
Agglomeration & planetesimals
Mature planetary system
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Planetary systems and the
origins of life
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How do planets form?
How are circumstellar disks
like our Solar System?
How are habitable zones
established?
Spitzer image
Simulated JWST image:
Fomalhaut at 24 microns
• NIRCam will use coronagraphy to image protoplanetary
disks and extra-solar giant planets
• NIRCam will obtain images and spectra of circumstellar
disks, comets, moons, and Kuiper Belt Objects in the
outer Solar System
Titan
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NIRCam’s Wavefront Sensing Role
First Light
After
segment
capture
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NIRCam provides the imaging data needed
for wavefront sensing.
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Dispersed Hartmann Sensors at 0° and 60°
orientations permit phasing of adjacent mirror
elements.
Coarse
phasing
w/DHS
DHS at pupil
Spectra recorded
by NIRCam
Fine phasing
After coarse phasing
Fully aligned
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On-line Resources
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STScI JWST Home Page
http://www.stsci.edu/jwst/
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JWST Primer
http://www.stsci.edu/jwst/doc-archive/handbooks
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STScI NIRCam Page
http://www.stsci.edu/jwst/instruments/nircam
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University of Arizona NIRCam Page
http://ircamera.as.arizona.edu/nircam/
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University of Arizona NIRCam Girl Scouts Page
http://zeus.as.arizona.edu/~dmccarthy/GSUSA/index.htm
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NASA NIRCam Page
http://www.jwst.nasa.gov/nircam.html
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