Astronomy |
Ecology |
We detected micro-gauss magnetic fields correlated over 10s of kiloparsecs in the early Universe in a radio polarimetric study of some of the most distant and luminous radio galaxies. That the young Universe had magnetic fields similar to present day galaxies, and many orders of magnitudes stronger than predicted by theoretical models, was a challenge to our understanding of the origin of magnetic fields in the Universe.
Low frequency radio observations are essential for studying cosmologically significant phenomena at high redshifts (Early Universe) and rare types of sources such as cluster halos and relics. Even though the Giant Metrewave Radio Telescope in Pune, India, has been the world's largest and the most sensitive low frequency interferometer since its commissioning in 2000 its images have been 5-15 times poorer than expected on account of radio interference from human activities. I developed a conceptually new approach to eliminate this contamination using a software algorithm, which can improve image sensitivity by factors of 3-10. This algorithm was adapted for the Very Large Array, the world's premier radio telescope, and incorporated into the standard radio astronomy analysis software which is used by astronomers all over the world.
Pulsars are fast-rotating neutron stars which emit radiation in periodic pulses from the magentic poles. Astronomers have been trying to detect emission outside the "pulse". since the 1970s. All the extra-pulse detections till date have been in very young pulsars with high spin-down luminosities and are believed to be emission not from the pulsar but the surrounding pulsar wind nebula. Using the GMRT interferometer in a non-standard high-time resolution mode we detected off-pulse emission from two old pulsars (so selected to avoid wind nebula emission). This unexpected and yet much sought-after (for over 3 decades) observation is an important input into theoretical models which seek to understand pulsar emission.
High quality optical and infrared images from the then newly commisioned 8m class Very Large Telescope of ESO in Chile, combined with X-ray observations were used to carry out one of the most comprehensive analysis of mass distribution in a galaxy cluster (MS1008-1224) using the gravitational wek-lensing effect. These high quality images also helped us to identify a background cluster which had been lensed by MS1008 – the first known case of cluster-cluster lensing.
The first bird species new to science discovered in mainland India since 1948 and the first discovered and described by an Indian ornithologist. This unexpected discovery received great attention all over the world and was hailed by BirdLife International as the most significant ornithological event in over half a century.
This is a comprehensive report on a multi-faceted effort to secure the long-term conservation of Eaglenest wildlife sanctuary in Arunachal Pradesh. It irecords a journey of exploration and discovery in biodiversity, social and societal dynamics, economic and commercial issues, governance, and conservation - in short all that goes into making human society.
This project has resulted in the discovery of many taxa new to science - from birds to herpetofauna to insects and scorpions - and the rediscovery of many species after a century or more.
Images from this report featured in the report of the Central Empowered Committee of the Supreme Court of India ("Saving India's Forests and Wildlife") and the data was used in a recommendation of the same Committee which was instrumental in stopping a major highway project through Eaglenest.
The conservation-oriented local-community ecotourism initiative under this project bagged an award as the best ecotourism destination of the CNN-IBN in 2009. I received the inaugural WWF-India conservation award for combining conservation with research.
28 February 2013, Ramana Athreya