Download Beyond HST: The Universe in High

Beyond HST: The Universe in High-Definition –
UVOIR Space Astronomy in 2030
Julianne Dalcanton & Marc Postman
Science with HST IV Meeting
Rome, Italy
March 18, 2014
Long History of Large Space
UVOIR Telescope Concepts
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VLST – 10m-16m concept (ca. 1989)
SUVO – 4m concept (ca. 1998-1999)
Workshop on 10m - 30m VLST (2003)
MUST – 10m concept (ca. 2004-2005)
ATLAST – 8m-16m concepts (ca. 2008-2010)
EUVO – European 8m concept (ca. 2013)
Modular Assembled 20m concept (ca. 2013)
Scientifically compelling for
over 2 decades!
(Average Aperture Diameter – 13.5 meters)
“Can we find another planet like Earth orbiting a
nearby star? To find such a planet would complete
the revolution, started by Copernicus nearly 500
years ago, that displaced the Earth as the center of
the universe… The observational challenge is great
but armed with new technologies… astronomers
are poised to rise to it.”
- U.S. 2010 Astronomy Decadal Review
This is a question whose answer is sought by all of humanity
and the search will demand international cooperation.
The path has been laid …
for characterizing Earth 2.0
Kepler
Hubble
Spitzer
CoRoT
Ground-based Coronagraphs
Gaia
WFIRST
30-m class telescopes
TESS
JWST
PLATO
“Is there another Earth out there?” Thick Atmosphere
Methane
Oxygen
Fraction
with terrestrial planets = ηEarth
Fraction
with detectable biosignature = fBio
Water
If: ηEarth × fBioKepler DTel ~ 4m
~ 1 then
results 8-meter
The signature of life is encoded in the
ηEarth
× fBio < 1 then Dtel ~ 8m
spectrum
of the Earth
ηEarth> 12×Earths
fBio << 1 then DTel ~ 16m
Number of Exo-Earths in 1 year
of total integration time
Optical
Near-Infrared
16-meter
70
a
60
50
40
30
≤ 4 Earths
20
4-meter
10
0
2-m
4-m
8-m
16-m
Telescope Size
Above: Distribution of all FGK stars within 45 pc of the Sun
where a R=70 spectrum of an Earth-twin could be acquired
in <500 ksec shown as a function of telescope aperture.
Assumes eta_Earth = 0.1 and IWA = 2λ/D.
R=500 Spectrum of 1 Earth-mass Terrestrial Exoplanet at 10 pc
Exposure: 503 ksec on 8-m
56 ksec on 16-m
Reflectance ∝ (Planet Mass)2/3
5 Earth-mass: 172 ksec on 8-m
Bkgd: 3 zodi
Contrast: 10-10
SNR=10 @ 760 nm
H 2O
H 2O
H 2O
H 2O
O2(α)
O2(B)
H 2O
H 2O
O2(A)
O2(A) Detail:
@ 750 nm
We don’t expect all habitable worlds to have spectra like this but interpreting their spectra will require this kind of instrumental capability.
Detec5ng Diurnal Photometric Variability in Exoplanets Ford et al. 2003: Model of broadband photometric temporal variability of Earth
Reflectivity
0.09
Earth at 10 pc
0.08
16-m 8-m
4-meter
Earth at 20 pc
0.07
~9 days
16-m
0.06
0.05
0
8-meter
0.5
1
4-meter
1.5
2
2.5
3
Time (days)
Require S/N ~ 20 (5% photometry) to
detect ~20% temporal variations in
reflectivity.
Reconstruction of Earth’s land-sea ratio
from disk-averaged time-resolved
imaging with the EPOXI mission.
3.5
4
4.5
5
5.5
6
Developing a Shared Vision
Exoplanets
Everything Else
In the UVOIR,
the goals and
requirements are
very similar.
Developing a Shared Vision
Exoplanets
Both
Everything Else
•  Large aperture
•  Diffraction limited
•  Optical & NIR
•  Coronagraph or
•  UV capabilities
•  Superb mirror
•  Broad instrument
starshade
stability
suite
Developing a Shared Vision
Exoplanets
Everything Else
+
One mission + Broad science = Large Community
Emerging science themes
•  Exoplanets
•  “The Universe in High-Definition”
HDST: High-Definition Space Telescope
24x pixel density
UltraHD
SDTV
3820x2160
720x480
24x image sharpness
HST
2.4 meter
HDST
12 meter
HDST: Breaking Resolution Barriers
Redshift
0.1 0.3 1 2 3
HST
JWST
100 pc everywhere!
HDST8
HDST16
10 pc @ 100 Mpc
1 pc @ 10 Mpc
0.1 pc @ 1 Mpc
LMC
M31
M87/Virgo
Coma
Bullet
Cluster
Size scales
1 pc
5 pc
~200 pc
HDST: Resolving 100 pc star forming regions everywhere
in the universe! 1 pc resolved out to 10-25 Mpc.
ALMA: molecular gas on ~0.1-0.5” scales
JWST: Heavily enshrouded stars
HDST: Emerging stars
HDST: Breaking Resolution Barriers
Redshift
0.1 0.3 1 2 3
HST
JWST
HDST8
HDST16
Orion
Bulge
LMC
M31
M87/Virgo
Coma
Bullet
Cluster
General Astrophysics Drivers
•  Large aperture: Throughput + Resolu5on •  UV (90 nm) through NIR (>2.5 mm, non-­‐cryo) -­‐  Issues: Coa5ngs, Compa5bility w/ Coronagraphy •  Large FOV + Spectroscopic Mul5plexing -­‐  Issues: Tradeoff between cost of more complex instruments vs. efficiency gains The Case for UV Multiplexing
A true multi-object / IFU capability in the UV would trigger a revolution in our ability to
dissect gas flows, and the stellar populations that give rise to them, with dense sampling
of spatial variations and all relevant physical variables.
Would also support intensive
spectroscopy of every
Magellanic Cloud OB star.
Also would permit detailed mapping of
UV continuum and line SFR metrics,
spatially resolved, from z = 0 to z ~ 1.
Dissecting Halo Gas w/ Background QSO
Simulations from Shen et al. 2012
metal-rich
outflow
metal-poor
infall
900 - 1150 Å
Slide credit: J. Tumlinson
HI column
densities & OVI
“Parallel” Astrophysics During Long Exoplanet Spectroscopic Observa5ons •  Es5mated median single-­‐visit exposure 5me for obtaining an exoplanet spectrum is ~100 ksec. •  Will allow parallel deep imaging of nearby fields to 10-­‐sigma limi5ng depths of 33 AB mag in UV, visible and 32 AB mag in NIR. 19
Considerations:
•  Need big leap in aperture (compared to HST) •  Guaranteed discovery space, even with long launch 5me. •  Highly synergis,c with many upcoming facili5es -­‐  TESS, JWST, EUCLID, WFIRST, PLATO, ATHENA+ -­‐  20-­‐40m ground-­‐based telescopes, LSST -­‐  ALMA, SKA How do we get there?
U.S. Activities:
•  ATLAST NASA Center (GSFC/JPL/MSFC) Study •  AURA “Beyond JWST” Commigee •  NASA “EXOPAG” & “COPAG” working groups •  Coronagraph & Starshade developments for WFIRST and Exoplanet Probe concepts Goal: Mature technology and mission
concepts in preparation for 2020 Decadal
Technology and Innovation
Enable HDST science
Lightweight Mirrors
~3x
16x
30x
Gemini Mirror
How much would an 8-m mirror weigh?
Gemini
HST
JWST
AMT
20,000 kg
7,000 kg
1,250 kg
650 kg
HST Mirror
JWST Mirrors
AMT Prototypes
Collecting Area per Launch Mass
(m2/kg)
0.01"
1"
Credit: E. Elliot
0.001"
JWST
0.1"
Spitzer
HST
0.0001"
1990"
2000"
2010"
Collecting Area per Launch Volume
(m-1)
Technology Changes the Cost Curve
0.01"
2020"
Year of Launch
(If we had JWST mirror technology in 1980, cost of HST would have been 8x lower)
Related Key Technologies
Starshade concepts
are being studied
by NASA.
Optical model has
been tested on ground
– confirms diffraction
theory upon which
design is based.
1e-8
1e-9
1e-10
High Performance Coronagraphs being
studied, one will fly on WFIRST
Non-cryogenic
Optics!
Dual foci:
•  Cass for UV and
Exoplanets
•  TMA for wider field
instruments
Active Wavefront
Sensing & Control
Systems
•  Heritage from
ground, WFIRST,
and other industry/
govt. applications
JWST heritage mirror
deployment design,
compatible with
existing and nearfuture launch vehicles.
Poten&al Space Science Strategy HST
“The people’s telescope”
2.0
JWST
Hubble
segmented optics in space
mirror control
WFIRST/AFTA
active
giga-pixel array
robotic servicing
Test HP Coronagraph
HDST: Hubble 3.0
Tests light-weight segmented optics
active optics control
human-operated robotic assembly
light-weight segmented optics
fully active optics control
tele-robotic servicing
giga-pixel array
Ultra-high contrast imaging ISS
commercial crew & SLS, and other heavy lift launch vehicles
TESS
Finding potentially habitable exoplanets that can be characterized by HDST
PLATO
ESA L4 Selection
2015
2020
Decadal Review in U.S.
2025
2030
2035
For this to Succeed, do…
•  Have a killer app with full community support.
•  Develop mission that is a must-do scientifically and that
cannot be done any other way.
•  Ensure project is highly-ranked by community reviews.
•  Identify & highlight complementarity with other facilities.
•  Still like the science and the project 10 – 20 years from
now.
•  Offer project science and grant support to the whole
community.
•  Keep selling the project to the community until launch
Slide credit: Rogier Windhorst
For this to Succeed, don’t…
•  Have community in-fighting
•  Have other projects canceled because of this one, or
perception thereof.
•  Have science and grant support for a selected few.
•  Ignore community input on project science priorities.
•  Ignore importance of great communication with patrons:
scientists, contractors, tax-payers, politicians
•  Ignore importance of great communication with
international partners.
Slide credit: Rogier Windhorst
Where We Are
•  UVOIR access from space is fundamental to
understanding the universe and the life within it.
•  “Game Changing” science requires substantial increase
in aperture.
•  Enabling such a capability requires alliances, so the
exoplanet and astrophysics communities need to work
together to make their next generation large UVOIR
space telescope the SAME mission.
•  NASA can lead such a mission but the mission will
require significant international partnerships.
•  Need your inputs on science cases, ideas for advancing
technologies, science instruments concepts and
strategies for international collaboration.
Giving input or Further Ques5ons •  This mee5ng •  hgp://www.aura-­‐astronomy.org/hdst •  Talk to any commigee member, at any 5me •  White papers always welcome Goal is to develop the most compelling mission that also serves the largest possible community. All input is welcome! Back Up Slides 30
31
32
Possible TMA Focal Plane Alloca5on 17 arc min
Guider
8 arc min
4 x 4 arcmin
Guider
Vis/NIR
4 x 4 arcmin
Wide Field Imager
Guider
4x4
arcmin
Integral Field
Unit (IFU)
Array
(may use Dichroic
for 2 channels)
8 x 8 arc min
Guider
4 x 4 arcmin
up to 4 x 4
arc min
4 x 4 arc min
25 arc min
WFOV Total Available Focal Plane
WFOV Science Focal Plane
From Lloyd Purves, GSFC
Multi-Object
Spectragraph
(MOS)