Transcript Document

LISA Prior to the Decadal Review
of Astronomy and Astrophysics
(and following the BEPAC report)
Tom Prince
Caltech/JPL
12th GWDAW
13 December 2007
The Importance of
Gravitational Wave Astronomy from Space
Recent NRC Review of the NASA Beyond Einstein Program
(BEPAC Report Released in September)
The Committee ranked LISA highest scientifically:
“On purely scientific grounds LISA is the mission that is the most promising
and least scientifically risky …
Thus, the committee gave LISA its highest scientific ranking”
This Talk:
Why (and how) LISA won and lost the BEPAC review
What did BEPAC say? A “good news” + “bad news” story
The current situation: a pivotal time for LISA
LISA advocacy: a key to the upcoming Decadal Review
2
What is “BEPAC”
 Beyond Einstein Program Assessment Committee, convened by the
National Research Council
 “Prompted by Congressional language inserted in the formulation of the
FY2007 budget”
–
Congress (Energy appropriations) inserted language critical of the progress
towards a joint dark energy mission
–
John Marburger (Director of OSTP) convened a meeting with Michael Griffin of
NASA and Ray Orbach of DOE and three advisory committee chairs resulting in
a decision to ask for an NRC study
 “NASA and DOE asked the NRC to prepare a report reviewing NASA’s
Beyond Einstein missions and recommend one mission for first
development and launch utilizing a Beyond Einstein funding wedge that
will start in 2009.”
–
Five missions (LISA, Con-X, JDEM, Inflation Probe, Black Hole Finder Probe)
–
Eleven mission candidates
– One mission candidate (SNAP/JDEM) has had significant DOE involvement
3
Some Observations & Comments
 The committee report is a very impressive achievement
–
The committee did a tremendous amount of work and it shows in the quality of
the report
–
The combined scientific, technical, cost, and management assessment was
very unusual for an NRC committee and together with the diversity of mission
types presented a considerable challenge to carrying out the charge of the
committee
 Charlie Kennel in his open briefing on the report mentioned “tension” and
“consensus” very early in his remarks
–
My understanding: Consensus was achieved through the endorsement of two
missions rather than a single mission. The report represents a true consensus
of the committee.
 Wording is often used carefully and purposefully
–
Words such as “first priority”, “highest ranking”, “flagship” have special
importance
4
Important Statements on LISA
“On purely scientific grounds LISA is the (Beyond Einstein) mission
that is most promising and least scientifically risky. Even with
pessimistic assumptions about event rates, it should provide
unambiguous and clean tests of the theory of general relativity in
the strong field dynamical regime and be able to make detailed
maps of space time near black holes. Thus, the committee gave
LISA its highest scientific ranking.”
“If the committee’s charge had been to design a complete multi-year
multi-mission program addressing comprehensive Beyond Einstein
goals, LISA would have been its flagship mission.”
“LISA is an extraordinarily original and technically bold mission
concept. The first direct detection of low-frequency gravitational
waves will be a momentous discovery, of the kind that wins Nobel
Prizes.”
(Many other quotable statements about LISA)
5
LISA Science and the BEPAC Review
 A tremendous effort was put
forth by the LISA science
community in articulating the
science rationale for LISA
 Excellent presentations and
contributions by many
individuals
 Simple but effective approach:
–
Don’t sell gravitational waves
as such,
–
Rather, show how important
gravitational waves are for
addressing some of the key
questions of astronomy and
physics
–
Result: peoples’ conception of
gravitational wave astronomy is
being changed
6
Absolute Distances from Black Hole Binaries
Waveforms of black hole
binaries give precise,
gravitationally calibrated
distances to high redshift
Absolute luminosity distances can be derived directly from
–
amplitude
–
1
orbital frequency Distance c
frequency2  t chirp  amplit ude
chirp time
–
1. Distances accurate to 0.1% to ~10% per event

2. Absolute,
physical calibration using only
gravitational physics
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Absolute Distances:
Hubble Constant and Dark Energy
H0 and Dark Energy parameters
potentially measured to <1%
 ~10’s of events expected to z~3; 100’s to z~20
 Cosmological distance requires redshift (either host
identification or statistical)
 Noise from weak lensing
 Comparable precision to weak lensing, baryon acoustic
oscillations, clusters, and supernovae techniques
 Absolute & Independent measurement
8
Absolute Distances:
Hubble Constant and Dark Energy
H0 and Dark Energy parameters
potentially measured to <1%
“LISA also has the potential to measure the dark energy
equation of state, along with the Hubble constant and other
cosmological parameters. Through gravitational wave form
measurements LISA can determine the luminosity distance of
sources directly. If any of these sources can be detected and
identified as infrared, optical or x-ray transients and if their
redshift can be measured, this would revolutionize
cosmography by determining the distance scale of the universe
in a precise, calibration-free measurement.” (NRC BEPAC)
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Will We See Electromagnetic Signals from BH mergers?
 Not guaranteed, but if detected yields
exciting scientific return
 Host galaxy identification provides unique
information on galaxy-BH co-evolution
 Host galaxy identification allows precision
determination of distance-redshift relation
 LISA will provide few-degree error boxes and
time of merger months before launch
 Error boxes shrink to degree or sub-degree
size as signal-to-noise increases and merger
approaches
The first LISA detections of massive
Black Hole mergers will mobilize
global astronomical resources and be
an astronomical event of enormous
excitement. These are the most
energetic events in the universe since
the Big Bang.
10
LISA’s Science Success
 The committee found that LISA was the only mission that
addressed all three of the committee’s major science questions:
–
What powered the Big Bang?
– Only two missions mentioned, Inflation Probe and LISA
–
How do Black Holes Manipulate Space, Time, and Matter?
– LISA appeared to receive the highest ranking on this question
–
What is the Mysterious Dark Energy Pulling the Universe Apart?
– LISA was one of three missions mentioned
– Statement: If any sources are detected electromagnetically, LISA could
“revolutionize cosmography by determining the distance scale of the
universe in a precise, calibration-free measurement”
 In addition: Very strong statements on LISA’s potential for
unexpected discoveries
11
LISA Mock LISA Data Challenge & BEPAC
Challenge 2: “the whole Enchilada”
12
The Bad News
Executive Summary:
Finding 5. The ESA-NASA LISA Pathfinder mission that is scheduled
for launch in late 2009 will assess the operation of several critical
LISA technologies in space. The committee believes it is more
responsible technically and financially to propose a LISA new start
after the Pathfinder results are taken into account. In addition,
Pathfinder will not test all technologies critical to LISA. Thus, it
would be prudent for NASA to invest further in LISA technology
development and risk reduction,to help ensure that NASA is in a
position to proceed with ESA to a formal new start as soon as
possible after the LISA Pathfinder results are understood.
“The next highest priority (after JDEM) for funding from the current
2009 Beyond Einstein NASA budget wedge is to accelerate the
maturation of those mission critical LISA technologies that are
currently at low technology readiness levels. This funding will be
needed until and if NASA initiates a post-Pathfinder mission start
for LISA.”
13
A note on the BEPAC $$ estimates
 Is LISA really a $3.2B mission?
 Some important points
–
BEPAC estimates were in “Real Year” dollars and go out to FY25
–
The BEPAC estimated $641M for mission operations and data
analysis!
– But, LISA data will fit on an iPOD in 2020 and LISA does not point (i.e.
operations are VERY simple and data pipeline is low volume)
– LISA project estimate was about $200M (RY)
–
Once differences in mission operations and data analysis and launch
vehicle costs are taken into account, BEPAC and project numbers
agree to within about 20%
–
In FY06$$, LISA is a $1.6-2.0B mission
14
(DDT&E: Design, Development, Test, and Evaluation)
15
Follow-on to BEPAC Report
 We have a window of opportunity to advocate for Beyond Einstein and
LISA given the strong endorsement of the program and the mission by the
NRC committee
–
Advocacy should be a major focus for the gravitational wave community in the
coming months
–
Important in both Europe (Cosmic Vision selection) and US (Decadal Review
prioritization)
–
Decadal Review will start in (early?) 2008
 Important actions:
–
Get out and give colloquia and seminar talks at your own institution and other
universities
–
Talk to your physics and astronomy colleagues about the importance of LISA
–
Get your university magazine to do an article on LISA
–
Write, or better yet, visit your congressional representatives or their staff - let
them know how important funding of space science is and how exciting the
Beyond Einstein program is
–
Talk to NASA Headquarters - tell them how important LISA is to astronomy and
astrophysics
16
Some Talking Points
 LISA was the highest ranked mission scientifically in the recent
BEPAC review, conducted by the National Academy of
Science/National Research Council. Two missions were singled
out for strong recommendations: JDEM to start first, LISA starting
a few years later as the recommended flagship of the Beyond
Einstein program.
 LISA is guaranteed to see many thousands of gravitational wave
sources, some with signal-to-noise of a thousand or more. These
will provide us with many exciting new ways of doing astronomy
and physics
 LISA is a well-developed concept. The basic mission architecture
has been stable for almost a decade. Formulation studies are
ongoing in Europe and the United States.
 Many of LISA's flight systems already exist as engineering
prototypes or flight articles for the LISA Pathfinder mission
scheduled for launch in 2010
17
LISA: Strongly Endorsed in all Recent Reviews
Astronomy & Astrophysics in the New Millennium (NRC - 2001)
“LISA is unique among the recommended new initiatives in that it is designed to
detect the gravitational radiation predicted by Einstein’s theory of general
relativity. The direct measurement of gravitational radiation from astrophysical
sources will open a new window onto the universe and enable investigations of
the physics of strong gravitational fields.”
Quarks to Cosmos (NRC - 2003)
LISA and Con-X have “great potential to address questions that lie at the boundary
between physics and astronomy”.
Beyond Einstein (BE) Roadmap (NASA - 2003)
“The cornerstones of the program are two Einstein Great Observatories, Con-X and
LISA.”
Physics of the Universe (NSTC/OSTP - 2004)
The execution of the LISA mission is “necessary to open up this powerful new
window on the universe and create the new field of gravitational wave
astronomy.”
“Mid-course” Review of Decadal Study (NRC - 2005)
LISA and Con-X “will provide a broad and flexible science return across all of
astrophysics as have HST, CGRO, Chandra and Spitzer”.
Beyond Einstein Program Assessment Committee (NRC - 2007)
“On purely scientific grounds LISA is the (Beyond Einstein) mission that is most
promising and least scientifically risky ... Thus, the committee gave LISA its
highest scientific ranking.”
“If the committee’s charge had been to design a complete multi-year multi-mission
program addressing comprehensive Beyond Einstein goals, LISA would have
been its flagship mission.”
“LISA is an extraordinarily original and technically bold mission concept. The first
direct detection of low-frequency gravitational waves will be a momentous
discovery, of the kind that wins Nobel Prizes.”
18
Backup
Charge to the Committee
1.
2.
Assess the five proposed Beyond Einstein missions and recommend
which of these five should be developed and launched first, using a
funding wedge that is expected to begin in FY2009. The criteria for
these assessments include:

Potential scientific impact within the context of other existing and planned
space-based and ground-based missions; and

Realism of preliminary technology and management plans, and cost estimates
Assess the Beyond Einstein missions sufficiently so that they can act as
input for any future decisions or the next Astronomy and Astrophysics
Decadal Survey on the ordering of the remaining missions. This second
task element will assist NASA in its investment strategy for future
technology development within the Beyond Einstein Program prior to the
results of the Decadal Survey.
(Note: 2nd criteria (sub-bullet) very unusual for an NRC committee. Usually
this is NASA’s domain)
20
LISA-Related Findings and Recommendations
Executive Summary:
Finding 3. Two mission areas stand out for the directness with which
they address Beyond Einstein goals and their potential for broader
scientific impact: LISA and JDEM.
Finding 4. LISA is an extraordinarily original and technically bold
mission concept. LISA will open up an entirely new way of observing
the universe, with immense potential to enlarge our understanding
of physics and astronomy in unforeseen ways. LISA, in the
committee’s view, should be the flagship mission of a long-term
program addressing Beyond Einstein goals.
Finding 5. The ESA-NASA LISA Pathfinder mission that is scheduled
for launch in late 2009 will assess the operation of several critical
LISA technologies in space. The committee believes it is more
responsible technically and financially to propose a LISA new start
after the Pathfinder results are taken into account. In addition,
Pathfinder will not test all technologies critical to LISA. Thus, it
would be prudent for NASA to invest further in LISA technology
development and risk reduction,to help ensure that NASA is in a
position to proceed with ESA to a formal new start as soon as
possible after the LISA Pathfinder results are understood.
21
LISA-Related Findings and Recommendations
Executive Summary:
Finding 8. The present NASA Beyond Einstein funding wedge alone is
inadequate to develop any candidate Beyond Einstein mission on its
nominal schedule. However, both JDEM and LISA could be carried
out with the currently forecasted NASA contribution if DOE's
contribution that benefits JDEM is taken into account and if LISA's
development schedule is extended and funding from ESA is
assumed.
Recommendation 2. NASA should invest additional Beyond Einstein
funds in LISA technology development and risk reduction, to help
ensure that the Agency is in a position to proceed in partnership
with ESA to a new start after the LISA Pathfinder results are
understood.
“The next highest priority (after JDEM) for funding from the current 2009
Beyond Einstein NASA budget wedge is to accelerate the maturation of
those mission critical LISA technologies that are currently at low
technology readiness levels. This funding will be needed until and if NASA
initiates a post-Pathfinder mission start for LISA.”
22
Criteria for mission assessment

Provided at webcast briefing by Charlie Kennel
1. How do they advance goals of Beyond Einstein?
2. How do they provide contributions to a broader range of scientific
questions?
3. What is their potential for revolutionary discovery?
4. What is their scientific risk?
5. What is their readiness?
6. Will there be another space mission that can compete or ground-
based instrumentation that can compete?
“Technical readiness was a particular concern for a 2009 start.”
23
24
[New start = Start of Implementation]
25
Committee on Astronomy and
Astrophysics
Co-Chairs: Meg Urry
Chuck Bennett
Astro 2010
The Next Decadal Survey in Astronomy & Astrophysics
• Board on Physics and Astronomy (lead)
– Anneila Sargent, Chair
– Jon Bagger, Executive Committee
– Don Shapero, Executive Officer
• Space Studies Board
– Len Fisk, Chair
– Marcia Smith, Executive Officer
• Committee on Astronomy and Astrophysics
– Meg Urry (BPA) & Chuck Bennett (SSB), co-chairs
– 2-year planning process for Astro 2010
– CAA going into hibernation (during survey)
Astro 2010 Current Status
• Internal proposal at NRC is approved; planning
can proceed
• April 28, 2007 meeting under auspices of BPA
and SSB
– BPA, SSB astronomers plus several others
– How to adjust survey model to changed
circumstances?
– Developed guiding principles for survey
• Proposal submitted to NASA, NSF, DOE
• Survey will not start (and committee will not be
selected) until it is funded by agencies
– Hope to start in early 2008
Astro 2010 Guiding Principles (1)
• Community involvement
– Already town meetings at AAS, APS
– Will be extensive, on the Bahcall model
• Organization of panels
– Re science v. , open issue
• Evaluating cost and technical readiness
– BEPAC model? Independent assessment
• Unrealized projects - include in prioritization
Astro 2010 Guiding Principles (2)
• International community
– Cooperation on big projects?
• Scientific scope
– E.g., include Beyond Einstein science
– Other boundaries?
• Robustness to changing circumstances (e.g.,
cost growth, technical issues, changing
science)
– “Decision rules”
– Mid-term assessments?
Astro 2010 Guiding Principles (3)
• Makeup of committee
– Addition of other experts in science, policy, etc.
– Could help with friendly critique and credibility
• Send nominations, comments, suggestions
to
[email protected]