Transcript Document 7411005

LISA Update
Bernard Schutz
Albert Einstein Institute, Potsdam, Germany
and
Cardiff University, Wales
GWDAW-10, Brownsville, 14 December 2005
Current progress on LISA
 LISA in Formulation Phase study (Astrium, Germany)
 LISA Pathfinder on track for launch 2009
 LIST re-formed this year, sharpening science goals
 Strong focus on developing data analysis for LISA
 Recent technology review at Goddard
 Strong competition for funds and priority in both NASA and ESA
 Science from LISA
LISA
LISA
Hardware development
 Astrium (Germany) study of LISA supports Formulation Phase
activities (old Phase A and B).
 Design down to components, mass budgets, power budgets, data
telemetry requirements.
 Trade-off studies for reducing costs, increasing reliability
 LISA Pathfinder (LPF: ESA mission), launch 2009, will carry LTP
(European sensor) and two systems of thrusters and controls (from
US and Europe).
 LPF nearing end of Phase B, engineering models of all components
being qualified for launch.
 LPF tests completely all the LISA metrology, which is the most
challenging aspect of LISA. Ensures that LISA technology is at a state
of readiness for a 2009 mission, much earlier than target launch date
2013.
LISA
LISA
New LISA International Science Team
 Serve from 01/2005 for
 NASA membership
 ESA membership
 T Prince (co-chair)
 K Danzmann (co-chair)
 P Bender
 P Binetruy
 S Buchman
 M Cerdonio
 J Centrella
 M Cruise
 N Cornish
 C Cutler
 S Finn
 J Hough
 W Folkner
 P Jetzer
development, design
 J Gundlach
 Y Mellier
 Sets scientific priorities
 C Hogan
 B Schutz
 S Hughes
 T Sumner
 P Madau
 J-Y Vinet
 S Phinney
 S Vitale
 D Richstone
 K Thorne
two years.
 LIST meets twice/year,
operates Working
Groups and Task Forces
 Meetings open
 LIST guides project
–
Compact binaries and
merging black holes are
highest priority goals
–
EMRIs and backgrounds
are next priority level
 Guides development of
data analysis system
LIST website http://www.srl.caltech.edu/lisa/
LISA
LISA
Data analysis
 General recognition that LISA data analysis is challenging
–
Confusion of sources, problem not faced by ground-based projects
–
Low-frequency, long-duration sources
 ESA and NASA are organizing communities
–
JPL (Tom Prince) is NASA focus, had workshop 13-15 October
(http://www.tapir.caltech.edu/dokuwiki/workshop:start)
–
ESTEC (Oliver Jennrich) is ESA focus, had workshop 31 October. Issued
invitation to submit letter of intent: over 45 institutions, with 250 scientists,
responded.
–
Overall coordination provided by LIST Data Analysis Working Group (DAWG),
co-chaired by N Cornish and B Schutz
 Immediate goals
–
Developing infrastructure (LISA data generators, standards, etc)
–
Developing working, effective algorithms
–
Tool: mock data challenges
 Longer-term goal (by 2009?)
–
LISA
LISA
Delivery of architecture design, hand-over to professional programmers
Current issues
 Both NASA and ESA have funding constraints.
 Strong pressure from other missions waiting in queue, especially
after failure of recent Japanese X-ray mission.
 GSFC recently reviewed technology readiness of LISA and Con-
X. Waiting for report.
 NASA top-level management changes create uncertainty on
priorities. However, no changes in priorities have been made or
even suggested.
 ESA preparing to make a decision early next year on dropping
one existing mission from portfolio in order to cope with cost
overruns. LISA is one candidate.
 Important at this point to emphasize LISA’s extremely strong
science case!
LISA
LISA
LISA Science - 1
 LISA has both fundamental physics and astrophysics goals.
 Fundamental physics:
–
Tests of relativistic gravity using mergers of comparable-mass BHs:
– strong-gravity aspects (comparison with numerical relativity simulations)
– Hawking area theorem (before and after measurements of M and J)
– cosmic censorship hypothesis (is a/M > 1 after merger?)
–
Test uniqueness of Kerr (no hair theorem) by observing detailed
waveforms from Extreme Mass-Ratio Inspiral events (EMRI’s)
–
Observe low-frequency GWs for first time and validate weak-field GR
at these frequencies (eg polarization) by directly detecting GWs from
known systems with known orbital frequencies; perhaps observe
directly GWs from a system with known orbital decay (double pulsar
PSRJ0737-3039)
–
Observe bursts of GWs from cosmic strings or other exotic sources
LISA
LISA
LISA Science - 2
 Astrophysics
–
Study thousands of compact WD binaries, illuminate binary evolution,
interaction, mass spectrum, …
–
Detect a handful of coalescences of BHs in range 105-107 M, learn
when first massive holes formed and what this had to do with galaxy
formation.
–
Detect possibly dozens or more mergers of smaller BHs, learn how
supermassive BHs formed, learn how galaxies formed from fragments.
–
Using coordinated optical or X-ray observations, identify systems
containing BH mergers, measure cosmological acceleration, study dark
energy.
–
Detect hundreds of EMRIs, determine spectrum of masses and spins of
BHs in galaxies, study evolution of their central galactic bulges.
–
Look for a cosmological background of GWs, which might have arisen
during the epoch of the electroweak phase transition.
–
Discover unexpected sources, possibly components of the dark matter.
LISA
LISA