Download Case for INDIGO

An Indian adventure in
gravitational wave astronomy
IISER, Pune
Feb 4, 2012
Tarun Souradeep, IUCAA, Pune
Spokesperson, IndIGO Consortium
(Indian Initiative in Gravitational-wave Observations)
www.gw-indigo.org
Space Time as a fabric
Special Relativity (SR) replaced Absolute space and Absolute Time by flat 4dimensional space-time (the normal three dimensions of space, plus a fourth
dimension of time).
In 1916, Albert Einstein published his famous Theory of General Relativity, his
theory of gravitation consistent with SR, where gravity manifests as a curved
4-diml space-time
Theory describes how space-time is affected by mass and also how
energy, momentum and stresses affects space-time.
Matter tells space-time how to curve, and
Space-time tells matter how to move.
Space Time as a fabric
Earth follows a “straight path” in the curved
space-time caused by sun’s mass !!!
Einstein’s Theory of Gravitation
experimental tests
Mercury’s orbit
perihelion shifts
forward
•Mercury's elliptical path around the Sun shifts slightly with each orbit such
that its closest point to the Sun (or "perihelion") shifts forward with each
pass.
•Astronomers had been aware for two centuries of a small flaw in the orbit,
as predicted by Newton's laws.
•Einstein's predictions exactly matched the observation.
Einstein’s Theory of Gravitation
Matter bends light: Gravitational lens
First observational confirmation of Einstein’s
theory
The position of a distant star
on the sky shifts due to the
gravity of sun
Gravitational lens
Interesting Gravitational lens !
Einstein Ring
A nearer galaxy lenses a distant
one that happens to be exactly
along the same line of sight !!
Einstein
Cross
Four distinct images of
gravitationally lensed distant
quasar i!!
Grandest Gravitational lens
!
Distant galaxies beyond a cluster lens into arcs
Beauty & Precision
Einstein’s General theory of
relativity is the most
beautiful, as well as,
theory of modern physics.
It has matched all experimental tests
of Gravitation remarkably well.
Era of precision tests : GP-B,….
What happens when
matter is in motion?
Einstein’s Gravity predicts
• Matter in motion Space-time ripples
fluctuations in space-time curvature that
propagate as waves
Gravitational waves (GW)
•
In GR, as in EM, GW travel at the speed of light (i.e.,
mass-less) , are transverse and have two states of
polarization.
• The major qualitatively unique prediction
beyond Newton’s gravity
Begs direct verification !!!
A Century long Wait
• Einstein’s Gravitation (1916-2011):
 Beauty : symmetry in fundamental physics –mother of gauge theories
 & precision : matches all experimental tests till date to high precision
GW 
Astronomy
link
Gravitational Waves
-- travelling
space-time
ripples
Astrophysical systems are sources of copious GW emission:
are a fundamental
prediction
96% universe does not
Electromagnetic
signal!
•GW
emission efficiency
ofemit
mass
for BH mergers)
>>
• Existence
of GW(10%
inferred
beyond
doubt
(Nobel Prize 1993)
EM radiation via Nuclear fusion (0.05% of mass)
• Feeble
effectemitted
of GW
onfrom
a Detector
strong
sources
Energy/mass
in GW
binary >> EM
radiation
in the
lifetime
GW Hertz experiment ruled out.
• Universe is buzzing with GW signals from cores of astrophysical events
Only (SN,
astrophysical
systems
involving
huge
masses ,…
and accelerating
Bursts
GRB), mergers,
accretion,
stellar
cannibalism
very strongly are potential detectable sources of GW signals.
• Extremely Weak interaction, hence, has been difficult to detect directly
But also implies GW carry unscreened & uncontaminated signals
Indirect evidence for Gravity waves
Binary pulsar systems emit gravitational waves
Pulsar
Nobel prize
in 1993 !!!
Hulse and Taylor
14yr slowdown
of PSR1913+16
companion
Astrophysical Sources for Terrestrial GW
Detectors
• Compact binary Coalescence: “chirps”
– NS-NS, NS-BH, BH-BH
• Supernovas or GRBs: “bursts”
– GW signals observed in coincidence
with EM or neutrino detectors
• Pulsars in our galaxy: “periodic waves”
– Rapidly rotating neutron stars
– Modes of NS vibration
• Cosmological: “stochastic background” ?
– Probe back to the Planck time (10-43 s)
– Probe phase transitions : window to force
unification
– Cosmological distribution of Primordial black holes
14
Using GWs to Learn about the Source: an Example
Over two decades,
RRI involved in
computation of
inspiral waveforms
for compact
binaries & their
implications and
IUCAA in its Data
Analysis Aspects.
Can determine
• Distance from the earth r
• Masses of the two bodies
• Orbital eccentricity e and orbital inclination i
Neutron star-BH merger
Theoretical developments in classical GR
Principle behind direct Detection of GW
L ~ 1019 m / Hz (Achieved)  L ~ 1020 m / Hz
Detecting GW with Laser Interferometer
B
A
Path A
Path B
Difference in distance of Path A & B  Interference of laser
light at the detector (Photodiode)
Challenge of Direct Detection
Gravitational wave is measured in
terms of strain,
h
(change in length/original length)
2
L
L
h
Gravitational waves are very weak!
Expected amplitude of GW
signals
h  10
Measure changes of
20
 10
24
one part in thousand-billion-billion!
Detecting GW with Laser Interferometer
LIGO Optical Configuration
Power Recycled
Michelson
Interferometer
end test mass
Light bounces back and
forth along arms about
100 times
with Fabry-Perot Arm
Cavities
Light is “recycled”
about 50 times
input test mass
Laser
signal
beam splitter
Difference in distance of Paths  Interference of laser
light at the detector (Photodiode)
Courtesy: Stan Whitcomb
Terrestrial GW observatories
GEO-600
Germany
LIGO
4 kms
LIGO
Hanford
Washington USA
Laser Interferometer
Gravitational-Wave
Observatory
4 kms
LIGO
Livingston
Louisiana, USA
Why a GW Observatory in space ?
•Terrestrial GW observatories are limited to GW
frequencies above 10 Hz due to seismic noise.
( 10 Hz– 2000 Hz.)
•Interesting sources abundant at sub-Hertz
frequencies (milli-Hz to Hz range) are accessible.
•Easier to attain higher sensitivity with longer
baselines.
GW OBSERVATORY IN SPACE !!
LISA : Laser Interferometer Space
Antenna
A NASA, ESA joint proposal for space based GW Observatory (
expected launch 2011).
LISA : Laser Interferometer Space
A NASA,
ESA joint proposal for space based GW Observatory ( launch 2011).
Antenna
Frequency range: 10– 4 Hz - 1 Hz
A configuration of three `freely falling’ spacecrafts
in earth-like orbit linked by optical laser beams working as an
interferometer in space
The Orbit of LISA
The spacecraft are freely falling in the Sun’s field .
GW Source for LISA
Initial LIGO Sensitivity Goal
• Strain sensitivity
<3x10-23 1/Hz1/2
at 200 Hz
l
Sensor Noise
» Photon Shot Noise
» Residual Gas
l
Displacement Noise
» Seismic motion
» Thermal Noise
» Radiation Pressure
32
Era of Advanced GW detectors: 2015
Detector
Generation
Initial LIGO
(2002 -2006)
Enhanced LIGO
(2X Sensitivity)
(2009-2010)
Advanced LIGO
(10X sensitivity)
(2014 - …)
NS-NS
NS-BH
0.02
0.0006
BH-BH
10x sensitivity
10x dist reach
 1000 volume
 >> 1000X
0.0009 event
rate
(reach beyond
0.1
0.04
nearest0.07
super-
clusters)
40
10
A Day of Advanced
LIGO Observation >>
A year of Initial LIGO
20
observation
Global Network of GW Observatories improves…
1. Detection confidence 2. Duty cycle 3. Source direction 4. Polarization info.
GEO: 0.6km
LIGO-LHO: 2km+ 4km
VIRGO: 3km
future: LCGT 3 km
TAMA/CLIO
Time delays in milliseconds
India provides almost largest
possible baselines.
(Antipodal baseline 42ms)
LIGO-LLO: 4km
LIGO-India ?
LIGO-India: … the opportunity
Science Gain from Strategic Geographical Relocation
Source localization error
Courtesy:
S. Fairhurst
Launch of
Gravitational wave
Astronomy
Gravitational wave Astronomy :
vit
•Fundamental physics
•Astronomy & Astrophysics
•Cosmology
GWIC Roadmap Document
Scientific Payoffs
Advanced GW network sensitivity needed to observe
GW signals at monthly or even weekly rates.
• Direct detection of GW probes strong field regime of gravitation
 Information about systems in which strong-field and time dependent gravitation
dominates, an untested regime including non-linear self-interactions
• GW detectors will uncover NEW aspects of the physics
 Sources at extreme physical conditions (eg., super nuclear density physics), relativistic
motions, extreme high density, temperature and magnetic fields.
• GW signals propagate un-attenuated
weak but clean signal from cores of astrophysical event where EM signal is screened by
ionized matter.
• Wide range of frequencies  Sensitivity over a range of astrophysical scales
To capitalize one needs a global array of GW antennas separated by
continental distances to pinpoint sources in the sky and extract all the
source information encoded in the GW signals
LIGO-India: a good idea for GW community !
• Geographical relocation Strategic for GW astronomy
–
–
–
–
–
–
Increased event rates (x2-4) by coherent analysis
Improved duty cycle
Improved Detection confidence
Improved Sky Coverage
Improved Source Location required for multi-messenger astronomy
Improved Determination of the two GW polarizations
• Potentially large Indian science user community in the future
– Indian demographics: youth dominated – need challenges
– Improved UG education system will produce a larger number of students
with aspirations looking for frontline research opportunity at home.
• Substantial data analysis trained faculty exists in India and
Large Data Analysis Center Facilities are being planned under
the next five year plan for consolidated IndIGO participation in
LSC for Advanced LIGO
LIGO-India: … the opportunity
Strategic Geographical relocation
- the science gain
Sky coverage: ‘reach’ /sensitivity in different directions
Courtesy: Bernard Schutz
LIGO-India: … the opportunity
Strategic Geographical relocation: science gain
Polarization info
Homogeneity of Sky coverage
Courtesy: S.Kilmenko & G. Vedovato
Strategic Geographical relocation: science gain
Network
HHLV
HILV
AHLV
Mean horizon
distance
1.74
1.57
1.69
Detection
Volume
8.98
8.77
8.93
41.00%
54.00%
44.00%
Triple
Detection
Rate(80%)
4.86
5.95
6.06
Triple
Detection
Rate(95%)
7.81
8.13
8.28
47.30%
79.00%
53.50%
0.66
2.02
3.01
Volume Filling
factor
Sky Coverage:
81%
Directional
Courtesy:
Precision
Bernard Schutz
LIGO-India: Attractive Indian megaproject
• On Indian Soil with International Cooperation (no competition)
• Shared science risks and credits with the International community.
• AdvLIGO setup & initial setup risks primarily rests with USA.
– AdvLIGO-USA precedes LIGO-India by > 2 years.
– Vacuum 10 yr of operation in initial LIGO  2/3 vacuum enclosure + 1/3 detector assembly
split (US ‘costing’ : manpower and h/ware costs)
– Indian expters can contribute to AdvLIGO-USA : opportunity without primary responsibility
• US hardware contribution funded & ready
– AdvLIGO largest NSF project funded in USA
– LIGO-India needs NSF approval, but not additional funds from USA
• Expenditure almost completely in Indian labs & Industry
• Very significant Industrial capability upgrade in India.
• Well defined training plan  Large number of highly trained HRD
• Host a major data analysis facility for the entire LIGO network
Schematic Optical Design of Advanced LIGO detectors
Reflects International cooperation
Basic nature of GW Astronomy
LASER
AEI, Hannover
Germany
Suspension
GEO, UK
Highly MultiSchematic of Advanced LIGOdetectors
disciplinary
++
Astro
“Every single technology they’re touching they’re pushing, and there’s
a lot of different technologies they’re touching.”
(Beverly Berger, National Science Foundation Program director for gravitational physics. )
Large scale Ultra high Vacuum to be fabricated in India
10 mega -litres at nano-torr!!!
Multi-Institutional,
Multi-disciplinary
Consortium Nodal Institutions
1.
2.
3.
4.
5.
6.
7.
8.
9.
10.
CMI, Chennai
Delhi University
IISER, Kolkata
IISER, TVM
IISER, Pune
IIT Madras (EE)
IIT Kanpur (EE)
IUCAA, Pune
RRCAT, Indore
IPR, Ahmedabad
Members from
• TIFR Mumbai
• IISc, Bangalore
• RRI, Bangalore
• …
IndIGO Consortium – a brief history
• Dec. 2007 : ICGC2007 @IUCAA: Rana Adhikari’s visit & discussions
• 2009:
– Australia-India S&T collaboration (Iyer & Blair)
Establishing Australia-India collaboration in GW Astronomy
–
IndIGO Consortium: IUCAA Reunion meeting (Aug 9, 2009)
–
GW Astronomy Roadmap for India;
Note:
• 2009-2011:
– Meetings
at Kochi,
Pune, Shanghai,
Delhi
•IndIGO
was admitted
to GWICPerth,
in July
2011 : Intl.
recognition
of and
the growing
in India.
to Define,
Reorient
Respondcommunity
to the Global
(GWIC) strategies
for setting up the International GW Network.
•IndIGO has been accepted into the LIGO Science Collab.
– Bring together
scattered Indian Experimental Expertise;
(LSC) : pan-Indian 7 institutes: 15 members: Theory, DA +
Individuals
& Institutions
EXPERIMENTERS ) : Sept. 2011
• March 2011: IndIGO-I Proposal: Participation in LIGO-Australia
• May 2011+: LIGO-India..
IndIGO Consortium
Data Analysis &
Theory
Sanjeev Dhurandhar
Bala Iyer
Tarun Souradeep
Anand Sengupta
Archana Pai
Sanjit Mitra
K G Arun
Rajesh Nayak
A. Gopakumar
IUCAA
RRI
IUCAA
Delhi Univ.
IISER,-TVM
JPL , IUCAA
CMI
IISER-K
TIFR
T R Seshadri
Patrick Dasgupta
Sanjay Jhingan
L. Sriramkumar,
Bhim P. Sarma
Sanjay Sahay
P Ajith
Sukanta Bose,
B. S. Sathyaprakash
Soumya Mohanty
Badri Krishnan
Satyanarayan Mohapatra
Delhi University
Delhi University
Jamila Milia
IIT M
Tezpur Univ .
BITS, Goa
Caltech
Wash. U.
Cardiff University
UTB, Brownsville
Max Planck AEI
UM, Amherst
Instrumentation & Experiment
70
C. S. Unnikrishnan TIFR
60
G Rajalakshmi
TIFR
P.K. Gupta
RRCAT
50Raja
Sendhil
RRCAT
S.K. Shukla
RRCAT
Raja Rao
RRCAT exx
40
Anil Prabhakar,
IIT M
Shanti30
Bhattacharya
IIT M
Pradeep Kumar,
IIT K
Ajai Kumar
IPR
20
S.K. Bhatt
IPR
Vasant Natarajan
IISc.
10
Umakant Rapol
IISER Pune
Shiva Patil
IISER Pune
0
Joy Mitra
IISER Tvm
2009
2010
S. Ghosh
IISER Kol
Supriyo Mitra
IISER Kol
Ranjan Gupta
IUCAA
Bhal Chandra Joshi
NCRA
Rijuparna Chakraborty Cote d’Azur
Rana Adhikari
Caltech
Suresh Doravari
Caltech
Expter
S. Sunil
U. W. Aus.
Rahul Kumar
DA U. of Glasgow
Biplab Bhawal
LIGO ex
Theory
K. Venkat
U. Washington
B. Bhadur
U. of Illinois
2011
LIGO-India: unique once-in-a-generation opportunity
LIGO labs LIGO-India
?
Advanced LIGO Laser
• Designed and contributed by Albert Einstein Institute, Germany
• Much higher power (to beat down photon shot noise)
– 10W
 180W (narrow sub kHz line width)
• Better stability
– 10x improvement in intensity (nano ppm) and frequency
stability (mHz)
• Unique globally. Well beyond current Indian capability. Would require years of
focused R &D effort. Both power and frequency stability ratings.
• AdvLIGO laser has spurred RRCAT to envisage planning development of
similar laser capability in the next 5 year plans. IIT M group also interested.
• Multiple applications of narrow line width laser : Freq time stand, precision
metrology, Quantum key distribution, high sensitivity seismic sensors (geo sc.),
coherence LIDAR (atm sc.), ….
Courtesy: Stan Whitcomb
50
Advanced LIGO Mirrors
•
• Larger size
– 11 kg  40 kg, 2534 cm
• Smaller figure error
– 0.7 nm  0.35 nm
• Lower absorption
– 2 ppm  0.5 ppm
• Lower coating thermal noise
Surface specs (/1000) : 100 x best optical telescope
• Surface specs currently available in India for much
smaller sizes /20
Feb 2011 Status
• All substrates delivered • Indian industry may now be challenged to achieve on
small scale, eg., for TIFR 3m prototype
• Polishing underway
• Reflective Coating process• Technology for such mirror useful for high optical
starting up
metrology and other specialized applications
Courtesy: Stan Whitcomb
51
Advanced LIGO Suspensions
• UK designed and contributed
test mass suspensions
•
Silicate bonds create quasimonolithic pendulums using
ultra-low loss fused silica fibres
to suspend interferometer optics
– Pendulum
Q ~105  ~108
– resonance subHz
four stages
– suppression 1/f^4
per stage (6 stages)
40 kg silica test
mass
Courtesy: Stan Whitcomb
52
52
LIGO-India: unique once-in-a-generation opportunity
“Quantum measurements”
to improve further via squeezed light:
• Potential technology spin-offs will impact quantum computing and
quantum key distribution (QKD) for secure communications. (IITM
approached by ITI for QKD development.)
• New ground for optics and communication technology in India
• High Potential to draw
the best Indian UG students, typically
interested in theoretical physics, into experimental science !!!
LIGO-India: … the challenges
LIGO-India : Vacuum
structure & engineering
1. Large scale ultra-high Vacuum enclosure
S.K. Shukla (RRCAT), A.S. Raja Rao (ex RRCAT),
S. Bhatt (IPR), Ajai Kumar (IPR)
To be fabricated by Industry with designs from LIGO. A pumped volume of 10000m3
(10Mega-litres), evacuated to an ultra high vacuum of nano-torr (10-9 torr ).
Spiral weld UHV beam tubes
1.2 m dia: 20 m sections.
Sections butt welded to 200m
Expansion Bellows btw 200m
beam sections, 1 m gate valves
UHV Optical tanks to house
mirrors : end, beam splitter,…
Courtesy: Stan Whitcomb
LIGO Vacuum
Equipment
• Large vacuum chamber fabrication under stringent UHV requirement
• Significant capability upgrade for Indian industry
• Comparable, but smaller UHV chambers in IPR facility
Courtesy: Stan Whitcomb
LIGO Beam
Tube
Constructed > 1 decade back.
Operating in Initial LIGO for ~10yrs
• LIGO beam tube under
construction in January 1998
• 16 m spiral welded sections
• girth welded in portable
clean room in the field
1.2 m diameter - 3mm stainless
50 km of weld
NO LEAKS !!
(10Mega-litres at nano-torr)
Major Engg. Challenge
Unprecedented scale
Courtesy: Stan Whitcomb
Beam Tube Construction
beamtube
transport
beamtube
install
Concrete
Arches
girth
welding
Courtesy: Stan Whitcomb
LIGO beam tube
enclosure
• minimal enclosure
• reinforced concrete
• no services
Courtesy: Stan Whitcomb
IndIGO - ACIGA meeting
59
•
Detector Installation using
Cleanrooms
Chamber access
through large
doors
Courtesy: Stan Whitcomb
Optics Installation
Under Cleanroom
Conditions
•High precision skills
• Low contamination labs & trained manpower for related
Indian labs & industry
• Application in other sciences, eg. Material sciences, Space ,
biotech ,…
Courtesy: Stan Whitcomb
Science Payoffs
New Astronomy, New Astrophysics, New Cosmology, New Physics
” A New Window ushers a New Era of Exploration in Physics & Astronomy”
–
–
–
–
–
Testing Einstein’s GR in strong and time-varying fields
Testing Black Hole phenomena
Understanding nuclear matter by Neutron star EOS
Neutron star coalescence events
Understanding most energetic cosmic events ..Supernovae, Gamma-ray bursts,
LMXB’s, Magnetars
–
–
–
–
New cosmology..SMBHB’s as standard sirens..EOS of Dark Energy
Phase transition related to fundamental unification of forces
Multi-messenger astronomy
The Unexpected !!!!!
Technology Payoffs
• Lasers and optics..Purest laser light..Low phase noise, excellent
beam quality, high single frequency power
• Applications in precision metrology, medicine, micro-machining
• Coherent laser radar and strain sensors for earthquake prediction
and other precision metrology
• Surface accuracy of mirrors 100 times better than telescope
mirrors..Ultra-high reflective coatings : New technology for other fields
• Vibration Isolation and suspension..Applications for mineral prospecting
• Squeezing and challenging “quantum limits” in measurements.
• Ultra-high vacuum system 10^-9 torr (1picomHg). Beyond best in
the region. The largest UHV system will provide industry a
challenge and experience.
• Computation Challenges: Cloud computing, Grid computing, new
hardware and software tools for computational innovation.
Concluding remarks on LIGO India
Thank you !!!
• Home ground advantage !!! Once in a generation opportunity
• Threshold of discovery and launch of a new observational window
in human history!! Century after Einstein GR, 40 yrs of Herculean global effort
• Cooperative, not competitive science
• India at the forefront of GW science with 2nd generation of detectors:
Intl. shared science risks and credit
• Low project risk: commit to established tech. yet are able to take on
challenges of advLIGO (opportunity without primary responsibility)
“Every high
singletechnology
technology gains
they’refor
touching
pushing, and there’s
• Attain
Indian they’re
labs & industries
a lot of different technologies they’re touching.”
(Beverly Berger, National Science Foundation Program director for gravitational physics. )
• India pays true tribute to fulfilling Chandrasekhar’s legacy:
”Astronomy is the natural home of general relativity”
An unique once-in-a-generation opportunity for India. India could
play a key role in Intl. Science by hosting LIGO-India.
Deserves National mega-science project status
Rewards and spinoffs
Detection of GW is the epitome of breakthrough science!!!
• LIGO-India  India could become a partner in international
science of Nobel Prize significance
• GW detection is an instrument technology intensive field pushing
frontiers simultaneously in a number of fields like lasers and
photonics. Impact allied areas and smart industries.
• The imperative need to work closely with industry and other end
users will lead to spinoffs as GW scientists further develop optical
sensor technology.
• Presence of LIGO-India will lead to pushing technologies and greater
innovation in the future.
• Increase number of research groups performing at world class levels
and produce skilled researchers.
Why is LIGO-India such an Attractive
Indian Science Project?
• India leads high visibility, fundamental science expt. that
has huge (international) public appeal !!!
• Indian academia and industry would be working together
• The project provides high-technology goals that sharpen &
showcase the abilities of Indian institutions and industry.
• The project will lead to significant human resources
development (HRD@home) in academic, technical and
industrial spheres. Produce highly skilled S & T workforce for
India
• Jobs at all levels for region hosting LIGO-India. Proximity to
world class science