An Indian adventure in gravitational wave astronomy Tarun Souradeep, IUCAA, Pune Spokesperson,...

An Indian adventure in gravitational wave astronomy Tarun Souradeep, IUCAA, Pune Spokesperson, IndIGO Consortium (Indian Initiative in Gravitational-wave Observations) www.gw-indigo.org IISER, Pune Feb 4, 2012

Special Relativity (SR) replaced Absolute space and Absolute Time by flat 4- dimensional 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 suns mass !!!

Einsteins Theory of Gravitation experimental tests Mercurys 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.

Einsteins Theory of Gravitation Matter bends light: Gravitational lens The position of a distant star on the sky shifts due to the gravity of sun First observational confirmation of Einsteins theory

Gravitational lens

Einstein Ring Einstein Cross A nearer galaxy lenses a distant one that happens to be exactly along the same line of sight !! Four distinct images of gravitationally lensed distant quasar i!! Interesting Gravitational lens !

Grandest Gravitational lens ! Distant galaxies beyond a cluster lens into arcs .

Beauty & Precision

What happens when matter is in motion?

Einsteins 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 Newtons gravity Begs direct verification !!!

A Century long Wait Einsteins Gravitation (1916-2011): Beauty : symmetry in fundamental physics mother of gauge theories & precision : matches all experimental tests till date to high precision Gravitational Waves -- travelling space-time ripples are a fundamental prediction Existence of GW inferred beyond doubt (Nobel Prize 1993) Feeble effect of GW on a Detector strong sources GW Hertz experiment ruled out. Only astrophysical systems involving huge masses and accelerating very strongly are potential detectable sources of GW signals. GW Astronomy link Astrophysical systems are sources of copious GW emission: GW emission efficiency (10% of mass for BH mergers) >> EM radiation via Nuclear fusion (0.05% of mass) Energy/mass emitted in GW from binary >> EM radiation in the lifetime Universe is buzzing with GW signals from cores of astrophysical events Bursts (SN, GRB), mergers, accretion, stellar cannibalism, Extremely Weak interaction, hence, has been difficult to detect directly But also implies GW carry unscreened & uncontaminated signals 96% universe does not emit Electromagnetic signal!

Pulsar companion Nobel prize in 1993 !!! Hulse and Taylor 14yr slowdown of PSR1913+16 Binary pulsar systems emit gravitational waves Indirect evidence for Gravity waves

Courtesy;: Stan Whitcomb 14 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

Using GWs to Learn about the Source: an Example Distance from the earth r Masses of the two bodies Orbital eccentricity e and orbital inclination i Can determine Over two decades, RRI involved in computation of inspiral waveforms for compact binaries & their implications and IUCAA in its Data Analysis Aspects.

Neutron star-BH merger

Theoretical developments in classical GR

Principle behind direct Detection of GW

Detecting GW with Laser Interferometer Difference in distance of Path A & B Interference of laser light at the detector (Photodiode) Path A Path B A B

Challenge of Direct Detection Gravitational wave is measured in terms of strain, h (change in length/original length ) Expected amplitude of GW signals Measure changes of one part in thousand-billion-billion! Gravitational waves are very weak!

Courtesy: Stan Whitcomb end test mass beam splitter signal LIGO Optical Configuration Laser Michelson Interferometer Michelson Interferometer input test mass Light is recycled about 50 times Power Recycled with Fabry-Perot Arm Cavities Light bounces back and forth along arms about 100 times Detecting GW with Laser Interferometer Difference in distance of Paths Interference of laser light at the detector (Photodiode)

GEO-600 Germany 600m Terrestrial GW observatories

LIGO Hanford Washington USA LIGO Livingston Louisiana, USA LIGO Laser Interferometer Gravitational-Wave Observatory 4 kms

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.

LISA : Laser Interferometer Space Antenna A NASA, ESA joint proposal for space based GW Observatory ( expected launch 2011). GW OBSERVATORY IN SPACE !!

LISA : Laser Interferometer Space Antenna A NASA, ESA joint proposal for space based GW Observatory ( launch 2011). 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 Suns field.

GW Source for LISA

32 Initial LIGO Sensitivity Goal Strain sensitivity

Era of Advanced GW detectors: 2015 10x sensitivity 10x dist reach 1000 volume >> 1000X event rate ( reach beyond nearest super- clusters ) A Day of Advanced LIGO Observation >> A year of Initial LIGO observation Detector Generation NS-NSNS-BHBH-BH Initial LIGO (2002 -2006) 0.020.00060.0009 Enhanced LIGO (2X Sensitivity) (2009-2010) 0.10.040.07 Advanced LIGO (10X sensitivity) (2014 - ) 401020

Global Network of GW Observatories improves Global Network of GW Observatories improves LIGO-LLO: 4km LIGO-LHO: 2km+ 4km GEO: 0.6km VIRGO: 3km future: LCGT 3 km TAMA/CLIO 1. Detection confidence 2. Duty cycle 3. Source direction 4. Polarization info. LIGO-India ? Time delays in milliseconds India provides almost largest possible baselines. (Antipodal baseline 42ms)

LIGO-India: the opportunity Science Gain from Strategic Geographical Relocation Source localization error Courtesy: S. Fairhurst Launch of Gravitational wave Astronomy

vit GWIC Roadmap Document Gravitational wave Astronomy : Fundamental physics Astronomy & Astrophysics Cosmology

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 Polarization info Homogeneity of Sky coverage Courtesy: S.Kilmenko & G. Vedovato Strategic Geographical relocation: science gain

NetworkHHLVHILVAHLV Mean horizon distance 1.741.571.69 Detection Volume 8.988.778.93 Volume Filling factor 41.00%54.00%44.00% Triple Detection Rate(80%) 4.865.956.06 Triple Detection Rate(95%) 7.818.138.28 Sky Coverage: 81% 47.30%79.00%53.50% Directional Precision 0.662.023.01 Strategic Geographical relocation: science gain Courtesy: 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 LASER AEI, Hannover Germany Suspension GEO, UK Reflects International cooperation Basic nature of GW Astronomy

Schematic of Advanced LIGOdetectors Large scale Ultra high Vacuum to be fabricated in India 10 mega -litres at nano-torr!!! Highly Multi- disciplinary Astro ++ Every single technology theyre touching theyre pushing, and theres a lot of different technologies theyre touching. (Beverly Berger, National Science Foundation Program director for gravitational physics. )

Multi-Institutional, Multi-disciplinary Consortium 1.CMI, Chennai 2.Delhi University 3.IISER, Kolkata 4.IISER, TVM 5.IISER, Pune 6.IIT Madras (EE) 7.IIT Kanpur (EE) 8.IUCAA, Pune 9.RRCAT, Indore 10.IPR, Ahmedabad Members from TIFR Mumbai IISc, Bangalore RRI, Bangalore Nodal Institutions

IndIGO Consortium a brief history Dec. 2007 : ICGC2007 @IUCAA: Rana Adhikaris visit & discussions 2009: Australia-India S&T collaboration (Iyer & Blair) Establishing Australia-India collaboration in GW Astronomy Establishing Australia-India collaboration in GW Astronomy IndIGO Consortium: IUCAA Reunion meeting (Aug 9, 2009) GW Astronomy Roadmap for India; 2009-2011: Meetings at Kochi, Pune, Shanghai, Perth, Delhi to Define, Reorient and Respond to the Global (GWIC) strategies for setting up the International GW Network. Bring together scattered Indian Experimental Expertise; Individuals & Institutions March 2011: IndIGO-I Proposal: Participation in LIGO-Australia May 2011+: LIGO-India.. Note: IndIGO was admitted to GWIC in July 2011 : Intl. recognition of the growing community in India. IndIGO has been accepted into the LIGO Science Collab. (LSC) : pan-Indian 7 institutes: 15 members: Theory, DA + EXPERIMENTERS ) : Sept. 2011

Data Analysis & Theory Sanjeev Dhurandhar IUCAA Bala Iyer RRI Tarun Souradeep IUCAA Anand Sengupta Delhi Univ. Archana Pai IISER,-TVM Sanjit Mitra JPL, IUCAA K G Arun CMI Rajesh Nayak IISER-K A.Gopakumar TIFR IndIGO Consortium IndIGO Consortium T R Seshadri Delhi University Patrick Dasgupta Delhi University Sanjay Jhingan Jamila Milia L. Sriramkumar, IIT M Bhim P. Sarma Tezpur Univ. Sanjay Sahay BITS, Goa P Ajith Caltech Sukanta Bose, Wash. U. B. S. Sathyaprakash Cardiff University Soumya Mohanty UTB, Brownsville Badri Krishnan Max Planck AEI Satyanarayan MohapatraUM, Amherst

C. S. Unnikrishnan TIFR G Rajalakshmi TIFR P.K. Gupta RRCAT Sendhil Raja RRCAT S.K. Shukla RRCAT Raja Rao RRCAT exx Anil Prabhakar, IIT M Shanti Bhattacharya IIT M Pradeep Kumar, IIT K Ajai Kumar IPR S.K. Bhatt IPR Vasant Natarajan IISc. Umakant RapolIISER Pune Shiva Patil IISER Pune Joy Mitra IISER Tvm S. Ghosh IISER Kol Supriyo MitraIISER Kol Ranjan Gupta IUCAA Bhal Chandra Joshi NCRA Rijuparna Chakraborty Cote dAzur Rana Adhikari Caltech Suresh Doravari Caltech S. Sunil U. W. Aus. Rahul Kumar U. of Glasgow Biplab Bhawal LIGO ex K. Venkat U. Washington B. Bhadur U. of Illinois Instrumentation & Experiment

LIGO labs LIGO-India ? LIGO-India: unique once-in-a-generation opportunity

Courtesy: Stan Whitcomb50 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 Whitcomb51 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 Feb 2011 Status All substrates delivered Polishing underway Reflective Coating process starting up Surface specs ( /1000) : 100 x best optical telescope Surface specs currently available in India for much smaller sizes /20 Indian industry may now be challenged to achieve on small scale, eg., for TIFR 3m prototype Technology for such mirror useful for high optical metrology and other specialized applications

Courtesy: Stan Whitcomb52 Advanced LIGO Suspensions UK designed and contributed test mass suspensions Silicate bonds create quasi- monolithic pendulums using ultra-low loss fused silica fibres to suspend interferometer optics Pendulum Q ~10 5 ~10 8 resonance subHz suppression 1/f^4 per stage (6 stages) 52 40 kg silica test mass four stages

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: unique once-in-a-generation opportunity

LIGO-India : Vacuum structure & engineering LIGO-India: the challenges

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 10000m 3 (10Mega-litres), evacuated to an ultra high vacuum of nano-torr (10 -9 torr ). Courtesy: Stan Whitcomb Spiral weld UHV beam tubes 1.2 m dia: 20 m sections. Sections butt welded to 200m UHV Optical tanks to house mirrors : end, beam splitter, Expansion Bellows btw 200m beam sections, 1 m gate valves

LIGO Vacuum Equipment Courtesy: Stan Whitcomb Large vacuum chamber fabrication under stringent UHV requirement Significant capability upgrade for Indian industry Comparable, but smaller UHV chambers in IPR facility

LIGO Beam Tube 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 Constructed > 1 decade back. Operating in Initial LIGO for ~10yrs

Concrete Arches beamtube transport beamtube install girth welding Beam Tube Construction Courtesy: Stan Whitcomb

IndIGO - ACIGA meeting59 LIGO beam tube enclosure minimal enclosure reinforced concrete no services Courtesy: Stan Whitcomb

Detector Installation using Cleanrooms Chamber access through large doors Courtesy: Stan Whitcomb

Optics Installation Under Cleanroom Conditions Courtesy: Stan Whitcomb High precision skills Low contamination labs & trained manpower for related Indian labs & industry Application in other sciences, eg. Material sciences, Space, biotech,

Science Payoffs New Astronomy, New Astrophysics, New Cosmology, New Physics A New Window ushers a New Era of Exploration in Physics & Astronomy Testing Einsteins 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, LMXBs, Magnetars New cosmology..SMBHBs 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.

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 2 nd 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) Attain high technology gains for Indian labs & industries India pays true tribute to fulfilling Chandrasekhars 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 Concluding remarks on LIGO India Every single technology theyre touching theyre pushing, and theres a lot of different technologies theyre touching. (Beverly Berger, National Science Foundation Program director for gravitational physics. ) Thank you !!!

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.

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 Why is LIGO-India such an Attractive Indian Science Project?

An Indian adventure in gravitational wave astronomy Tarun Souradeep, IUCAA, Pune Spokesperson,...

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Transcript of An Indian adventure in gravitational wave astronomy Tarun Souradeep, IUCAA, Pune Spokesperson,...