India’s gravitational wave observatory initiative IndIGO

     India’s gravitational wave observatory initiative IndIGO


Why IndIGO was in News?
The term IndIGO or Indian Initiative in Gravitational-wave Observations was in news in the second week of February 2016 as international physicists announced detection of gravitational waves for the first time since their prediction by Albert Einstein in 1916.


The waves were detected using the facilities at the existing three LIGO detectors that are located in Livingston, Louisiana and Hanford, Washington of the USA.

What is IndIGO?
IndIGO is an initiative to set up advanced experimental facilities, with appropriate theoretical and computational support, for a multi-institutional Indian national project in gravitational-wave astronomy. It is also touted as one of the large scale scientific projects undertaken in independent India in collaboration with global partners.

What is LIGO-India?
LIGO-India is the prime project under the IndIGO initiative. The Laser Interferometer Gravitational-wave Observatory or LIGO project operates three gravitational-wave (GW) detectors. Two are at Hanford in the state of Washington, north-western USA, and one is at Livingston in Louisiana, south-eastern USA.

Currently these observatories are being upgraded to their advanced configurations (called Advanced LIGO). The proposed LIGO-India project aims to move one Advanced LIGO detector from Hanford to India.

LIGO-India project is envisaged as an international collaboration between the LIGO Laboratory and three lead institutions in the IndIGO consortium: Institute of Plasma Research (IPR) Gandhinagar, Inter University Centre for Astronomy and Astrophysics (IUCAA), Pune and Raja Ramanna Centre for Advanced Technology (RRCAT), Indore.

LIGO lab would provide the complete design and all the key detector components. Indian scientists would provide the infrastructure to install the detector at a suitable site in India and would be responsible for commissioning it.


The proposed observatory would be operated jointly by IndIGO and the LIGO-Lab and would form a single network along with the LIGO detectors in USA and Virgo interferometer – an interferometer similar to LIGO, located close to Pisa, Italy.

How LIGO-India will be designed?
The proposed detector will be a Michelson Interferometer with Fabry-Perot enhanced arms of 4 km length and aims to detect differential changes in the arm-lengths as small as 10-23 Hz-1/2 in the frequency range between 30 to 800 Hz.


The design would be identical to that of the Advanced LIGO detectors that are being commissioned in the USA.

What are its scientific benefits?
• The scientific benefits of LIGO-India are enormous. Adding a new detector to the existing network will increase the expected event rates, and will boost the detection confidence of new sources by increasing the sensitivity, sky coverage and duty cycle of the network.

• But the dramatic improvement from LIGO-India would come in the ability of localizing GW sources in the sky. Sky-location of the GW sources is computed by combining data from geographically separated detectors ('aperture synthesis').

• Adding a new detector in India, geographically well separated from the existing LIGO-Virgo detector array, will dramatically improve the source-localization accuracies (5 to 10 times), thus enabling us to use GW observations as an excellent astronomical tool.


What will be its impact on Indian science, industry and education?

Impact on Indian science
• The proposed LIGO-India project will help Indian scientific community to be a major player in the emerging research frontier of GW astronomy.

• A major initiative like LIGO-India will further inspire frontier research and development projects in India.  The nature of the experiment is intrinsically multidisciplinary.

• It will bring together scientists and engineers from different fields like optics, lasers, gravitational physics, astronomy and astrophysics, cosmology, computational science, mathematics and various branches of engineering.


• In order to fully realize the potential of multi-messenger astronomy, the LIGO-India project will join forces with several Indian astronomy projects. Potential collaborators include the Astrosat project, future upgrades of the India-based Neutrino Observatory and optical/radio telescopes.

Impact on industry
The high-end engineering requirements of the project (such as the world's largest ultra-high vacuum facility) will provide unprecedented opportunities for Indian industries in collaboration with academic research institutions.


LIGO project has facilitated major industry-academic research partnerships in USA and Europe, and has produced several important technological spin offs. LIGO-India will provide similar opportunities to Indian industry.

Education and public outreach
• A cutting edge project in India can serve as a local focus to interest and inspire students and young scientists.

• The LIGO-India project involves high technology instrumentation and its dramatic scale will spur interest and provide motivation to young students for choosing experimental physics and engineering physics as career options.

• The ‘multi-spectral’ reach to physics will attract a large number of talented and motivated young researchers and students to the program, as it has done in other countries.


• The observatory will also be one of the very few research facilities in India of this scale, international relevance and technological innovation to which the general public and students can have access.

What is the present status of IndIGO?
Since 2009, the IndIGO Consortium has been involved in constructing the Indian road-map for Gravitational Wave Astronomy and a phased strategy towards Indian participation in realizing the crucial gravitational-wave observatory in the Asia-Pacific region.


In October 2011, LIGO-India was included in the list of Mega Projects under consideration by the then Planning Commission.

What is Indian Neutrino Observatory?
Similar to IndIGO, Indian Neutrino Observatory (INO) Project is another mega-science project. It is a proposed underground observatory to detect ephemeral particles called neutrinos.


The Union Cabinet cleared the project in 2015 to set up the laboratory in Tamil Nadu. However, the project has been stalled for over a year due to protests by activist groups, concerned over its environmental impact.

Indian scientists associated with detection of gravitational waves
Indian scientists have, over 30 years, contributed substantially to the recent discovery of gravitational waves. Notable among them are C V Vishveshwara, Bala Iyer, Anand Sengupta and Sanjib Mitra.

C V Vishveshwara and Bala Iyer were among the first in the world to solve Einstein’s equations to derive a mathematical model to explain how colliding black holes would look and what tell-tale signals they emitted.


While Anand Sengupta developed methods to ensure that both the LIGO detectors — separated by 3,000 kilometres — have caught the same gravitational wave, Sanjib Mitra has found ways to tell apart gravitational waves from various exotic stars.