This biographical article is written like a résumé .(January 2024) |
Dhruba J. Saikia | |
---|---|
Born | |
Alma mater | St. Edmund's School, Shillong; Hindu College, Delhi University; Gwyer Hall, Delhi University; Tata Institute of Fundamental Research, Mumbai |
Known for | Active galaxies, Radio galaxies and Quasars, Radio astronomy, Education |
Awards | Geeta Udgaonkar Award of the Tata Institute of Fundamental Research for the best Ph.D. thesis (1985-86); Young Scientist of the Year Award by the Indian National Science Academy (1985); Prof. M.K. Vainu Bappu Gold Medal of the Astronomical Society of India (1990) |
Scientific career | |
Fields | Astronomy, Astrophysics, Radio astronomy, Education |
Institutions | National Centre for Radio Astrophysics, TIFR; Jodrell Bank Observatory, University of Manchester; Queen's University, Kingston, Canada; University of Western Australia; Australia Telescope National Facility, CSIRO Astronomy and Space Science; Cotton University; Inter-University Centre for Astronomy and Astrophysics |
Thesis | PhD Thesis Jets and compact features in extragalactic radio sources (1985) |
Doctoral advisor | Vijay Kapahi, Govind Swarup |
Dhruba J. Saikia FNAsc is an Indian astrophysicist and radio astronomer, with a keen interest in education, especially higher education. He was a professor at the National Centre for Radio Astrophysics (NCRA), [1] part of the Tata Institute of Fundamental Research (TIFR) where he worked for over 40 years and is now at the IUCAA where he heads the Teaching Learning Centre and the National Resource Centre, which constitute the Astronomy Centre for Educators (ACE). Besides TIFR and IUCAA, he has been engaged in research and/or teaching at the Jodrell Bank Observatory of the University of Manchester, National Radio Astronomy Observatory USA, Queen's University at Kingston, Canada, Australia Telescope National Facility, CSIRO Astronomy and Space Science division, Australia, the University of Western Australia, Savitribai Phule Pune University and Cotton University, India.
Saikia's research interests are in the fields of extragalactic astronomy, radio astronomy and more recently education. Along with Vijay Kapahi, he contributed to the early development of the unification scheme for AGN, [2] and has been invited to review areas where he has made significant contributions. These include reviews titled Polarization properties of extragalactic radio sources with C. J. Salter, [3] Compact steep-spectrum and peaked-spectrum radio sources with Christopher P. O'Dea, [4] Jets in radio galaxies and quasars: an observational perspective, [5] and Decoding the giant extragalactic radio sources with Pratik Dabhade and Mousumi Mahato. [6] He has recently contributed a Chapter to the Indian Higher Education Report 2023 titled Institutional research in higher education: learning from an experiment at Cotton University. [7]
Dhruba J. Saikia was the founding Vice-Chancellor of Cotton University [8] in Guwahati when the historic Cotton College, founded in 1901, was converted to a university in 2012. He was the Dean of, the National Centre for Radio Astrophysics Faculty during 2007–2009, and a member of the statutory bodies of a number of institutions for varying periods. He was a member of the Senate of Indian Institute of Technology Guwahati, Academic Council of Tezpur University, Management Board for Centre of Plasma Physics - Institute for Plasma Research, Governing Board of Omeo Kumar Das Institute of Social Change and Development, Governing Board of IIIT Guwahati, Governing Board and Academic Council of Assam Don Bosco University and Academic Council, TIFR Deemed University. He was the Executive President of the Physics Academy of North East (PANE) from 2017 to 2019.
Saikia is also a wildlife enthusiast, especially of birds, [9] and contributes regularly to The Cornell Lab of Ornithology portal ebird.org. He was awarded the Adventurous eBirder of the Year in 2019 by Bird Count India. [10]
Dhruba Saikia was born on 21 January 1956 in Jorhat, Assam, which was the home of both his parents. He spent his early childhood and schooling years in the town of Shillong, Meghalaya. Both his parents were teachers. His mother Devika Saikia taught Assamese literature at Sankardev College, Shillong, while his father Debendra Nath Saikia taught Commercial geography at St. Anthony's College, Shillong. Dhruba Saikia studied in St. Edmund's School from 1961 to 1971, passing the Indian School Certificate Examination conducted by the University of Cambridge Local Examinations Syndicate in 1971.
After completing his school education in Shillong, Saikia, a National Science Talent Scholarship recipient, joined Hindu College, Delhi in 1972. He received his B.Sc. with Physics honours from Delhi University in 1975, and then joined Gwyer Hall for his postgraduate studies. He received his M.Sc. in physics from Delhi University in 1977, and soon took up a regular position in the Radio Astronomy Group of the Tata Institute of Fundamental Research, and joined at Ooty on 16 August 1977. It was an exciting time for the group. The Ooty Radio Telescope, built indigenously by a very young group led by Govind Swarup had produced many interesting results and provided additional evidence in support of the Big Bang model of the Universe just a couple of years earlier. [11] [12] [13]
After spending two years at Ooty, he shifted to the TIFR Centre in the campus of the Indian Institute of Science, Bengaluru, where he did most of his Ph.D. work, completing his thesis in 1985 under the guidance of Vijay Kapahi and Govind Swarup. The degree was awarded by the University of Bombay. It was an exciting period in radio astronomy when the Very Large Array in New Mexico came into operation producing high-quality radio images using techniques of self-calibration. [14] These observations demonstrated the ubiquitousness of radio jets in radio-loud active galactic nuclei. Saikia's thesis on jets and compact features in extragalactic radio sources was based extensively on observations made with the Very Large Array where he spent several months during the summer of 1982.
Saikia then moved on to take up a postdoctoral position at the Jodrell Bank Observatory of the University of Manchester in 1986. After spending a few enriching and fruitful years at the Jodrell Bank Observatory, he returned to Pune, India in 1989. The Radio Astronomy Group of TIFR was then in the process of setting up the National Centre for Radio Astrophysics at Pune, and building the Giant Metrewave Radio Telescope about 80 km north of Pune, [15] which continues to be one of the most powerful radio telescopes operating at low radio frequencies.
After joining the Radio Astronomy Group of TIFR on 16 August 1977, Saikia continued to be a part of this group which later became the National Centre for Radio Astrophysics, till his superannuation on 31 January 2018. During this period he also worked at a number of other institutions besides TIFR and Jodrell Bank Observatory. Saikia was a Visiting Professor and International visiting scholar at Queen's University at Kingston, Canada, during 2000–2001, working with Judith Irwin on nearby galaxies. He was a distinguished visitor at the Australia Telescope National Facility, CSIRO Astronomy and Space Science division, Sydney in 2009, and visiting professor, the International Centre for Radio Astronomy Research, University of Western Australia during 2009–2010. Saikia was a visiting scientist at the National Radio Astronomy Observatory, Socorro, New Mexico, USA in 2011, as part of the Resident Shared Risk Observing (RSRO) program, making the initial observations and testing data reduction procedures with Judith Irwin for the CHANG-ES (Continuum Halos in Nearby Galaxies—an EVLA Survey) project [16] with the then-newly Expanded Very Large Array and now known as the Karl G. Jansky Very Large Array.
In addition to his early interests and contributions to jets in active galactic nuclei (AGN) and unification schemes, [17] [18] his research interests cover a wide spectrum. These include the evolution of radio galaxies from their sub-galactic dimensions to the largest single objects in the universe spanning about 15 million light years, [19] [20] episodic or recurrent jet active activity in AGN, [21] radio continuum surveys, neutral atomic hydrogen in galaxies, clusters of galaxies, high energy emission from radio-loud AGN, starburst galaxies, outflows in nearby galaxies, star formation and AGN activity in nearby galaxies. He has been a part of major international collaborations such as the CHANG-ES project led by Judith Irwin, [22] LeMMINGs (Legacy e-MERLIN Multi-band Imaging of Nearby Galaxy Sample) survey [23] led primarily by Rob Beswick, Ranieri Baldi and Bil Dullo and SAGAN (Search and Analysis of GRGs with Associated Nuclei), [24] a systematic study of giant radio galaxies (GRGs) led by Pratik Dabhade.
In 2012, Saikia took up the position as the first vice-chancellor of Cotton University [25] (then known as Cotton College State University), Assam, India, which was established in 2012 on the foundations of the historic Cotton College established in 1901. [26] He continued as the vice-chancellor util 27 July 2017, seeing through the amalgamation of the college and the university into one unitary structure on 1 June 2017. [27] After his superannuation from TIFR on 31 January 2018, Saikia joined IUCAA in February 2018 and has been heading the Astronomy Centre for Educators (ACE) at IUCAA which consists of the Teaching Learning Centre and the National Resource Centre. At IUCAA he has been devoting his time to carrying out a wide range of programmes and creating resources for improving pedagogic processes in astronomy and astrophysics in institutions of higher education in India.
In recent years,[ when? ] Saikia's research interests have covered aspects of higher education in India. During 2012–2017, while setting up Cotton University, Saikia had been looking into some of the problems confronting higher education in India, and also underlining the importance of maintaining institutional-level data. Such data besides being important for research is also crucial for formulating policies and monitoring their outcomes. Some of the topics explored include areas of silence in debates on higher education outlined in an occasional paper published by the Nehru Memorial Museum and Library; [28] issues affecting research outcomes in our universities; [29] [30] and results of an experiment in Cotton University to engage with questions, such as the fairness and effectiveness of examination and evaluation systems, and the correlation of a student's academic performance with prior education and social background. [31] Saikia has also been advocating institutional research in higher educational institutions in India. [32]
Saikia was the Editor of the Bulletin of the Astronomical Society of India (BASI) from 2010 to 2015, [33] a quarterly journal published in English by the Astronomical Society of India (ASI), and was also the Series Editor of the Astronomical Society of India Conference Series. BASI has been merged with the Journal of Astrophysics and Astronomy since 2017 December. [34] Saikia was a member of the editorial board of Resonance, Journal of Science Education, published by the Indian Academy of Sciences and Springer from 2015 to 2020. He has co-edited two volumes: Low-Frequency Radio Universe along with D. A. Green, Yashwant Gupta and T. Venturi, published by the Astronomical Society of the Pacific in 2009, [35] and Fluid Flows to Black Holes, A tribute to S Chandrasekhar on His Birth Centenary along with Virginia Trimble and published by World Scientific in 2013. [36] He is presently an associate editor of astrophysics and space science, published by Springer. [37]
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Extragalactic astronomy is the branch of astronomy concerned with objects outside the Milky Way galaxy. In other words, it is the study of all astronomical objects which are not covered by galactic astronomy.
An active galactic nucleus (AGN) is a compact region at the center of a galaxy that emits a significant amount of energy across the electromagnetic spectrum, with characteristics indicating that the luminosity is not produced by stars. Such excess, non-stellar emissions have been observed in the radio, microwave, infrared, optical, ultra-violet, X-ray and gamma ray wavebands. A galaxy hosting an AGN is called an active galaxy. The non-stellar radiation from an AGN is theorized to result from the accretion of matter by a supermassive black hole at the center of its host galaxy.
Seyfert galaxies are one of the two largest groups of active galaxies, along with quasars. They have quasar-like nuclei with very high surface brightnesses whose spectra reveal strong, high-ionisation emission lines, but unlike quasars, their host galaxies are clearly detectable.
The Giant Metrewave Radio Telescope (GMRT), located near Narayangaon, Pune in India, is an array of thirty fully steerable parabolic radio telescopes of 45 metre diameter, observing at metre wavelengths. It is the largest and most sensitive radio telescope array in the world at low frequencies. It is operated by the National Centre for Radio Astrophysics (NCRA), a part of the Tata Institute of Fundamental Research, Mumbai. It was conceived and built under the direction of Govind Swarup during 1984 to 1996. It is an interferometric array with baselines of up to 25 kilometres (16 mi). It was recently upgraded with new receivers, after which it is also known as the upgraded Giant Metrewave Radio Telescope (uGMRT).
The National Centre for Radio Astrophysics is a research institution in India in the field of radio astronomy is located in the Pune University Campus, is part of the Tata Institute of Fundamental Research, Mumbai, India. NCRA has an active research program in many areas of Astronomy and Astrophysics, which includes studies of the Sun, Interplanetary scintillations, pulsars, the Interstellar medium, Active galaxies and cosmology and particularly in the specialized field of Radio Astronomy and Radio instrumentation. NCRA also provides exciting opportunities and challenges in engineering fields such as analog and digital electronics, signal processing, antenna design, telecommunication and software development.
Jayant Vishnu Narlikar is an Indian astrophysicist and emeritus professor at the Inter-University Centre for Astronomy and Astrophysics (IUCAA). He developed with Sir Fred Hoyle the conformal gravity theory, known as Hoyle–Narlikar theory. It synthesises Albert Einstein's theory of relativity and Mach's principle. It proposes that the inertial mass of a particle is a function of the masses of all other particles, multiplied by a coupling constant, which is a function of cosmic epoch.
Thanu Padmanabhan was an Indian theoretical physicist and cosmologist whose research spanned a wide variety of topics in gravitation, structure formation in the universe and quantum gravity. He published nearly 300 papers and reviews in international journals and ten books in these areas. He made several contributions related to the analysis and modelling of dark energy in the universe and the interpretation of gravity as an emergent phenomenon. He was a Distinguished Professor at the Inter-University Centre for Astronomy and Astrophysics (IUCAA) at Pune, India.
The Ooty Radio Telescope (ORT) is located in Muthorai near Ooty, in South Indian state of Tamil Nadu. It is part of the National Centre for Radio Astrophysics (NCRA) of the Tata Institute of Fundamental Research (TIFR), which is funded by the Government of India through the Department of Atomic Energy. The radio telescope is a 530-metre (1,740 ft) long and 30-metre (98 ft) tall cylindrical parabolic antenna. It operates at a frequency of 326.5 MHz with a maximum bandwidth of 15 MHz at the front end.
Somak Raychaudhury is an Indian astrophysicist. He is the Vice-Chancellor at Ashoka University and was the Director of the Inter-University Centre for Astronomy and Astrophysics (IUCAA), Pune. He is on leave from Presidency University, Kolkata, India, where he is a Professor of Physics, and is also affiliated to the University of Birmingham, United Kingdom. He is known for his work on stellar mass black holes and supermassive black holes. His significant contributions include those in the fields of gravitational lensing, galaxy dynamics and large-scale motions in the Universe, including the Great Attractor.
Govind Swarup was a pioneer in radio astronomy. In addition to research contributions in multiple areas of astronomy and astrophysics, he was a driving force behind the building of "ingenious, innovative and powerful observational facilities for front-line research in radio astronomy".
NGC 3862 is an elliptical galaxy located 300 million light-years away in the constellation Leo. Discovered by astronomer William Herschel on April 27, 1785, NGC 3862 is an outlying member of the Leo Cluster.
Vijay Kumar Kapahi was an Indian astrophysicist and the director of the National Centre for Radio Astrophysics, an autonomous division of Tata Institute of Fundamental Research. Known for his research on radio galaxies, quasars and observational cosmology, Kapahi was an elected fellow of all the three major Indian science academies – Indian Academy of Sciences, Indian National Science Academy and National Academy of Sciences, India – as well as of the Maharashtra Academy of Sciences. The Council of Scientific and Industrial Research, the apex agency of the Government of India for scientific research, awarded him the Shanti Swarup Bhatnagar Prize for Science and Technology for his contributions to physical sciences in 1987.
The Saraswati Supercluster is a massive galaxy supercluster about 1.2 gigaparsecs (4 billion light years) away within the Stripe 82 region of SDSS, in the direction of the constellation Pisces. It is one of the largest structures found in the universe, with a major axis in diameter of about 200 Mpc (652 million light years). It consists of at least 43 galaxy clusters, and has the mass of 2 × 1016 M☉, forming a galaxy filament.
Ajit Kembhavi is an Indian astrophysicist. He is presently a Professor Emeritus at the Inter-University Centre for Astronomy and Astrophysics, (IUCAA) at Pune, India, of which he was also a founder member. He also serves as a Vice President of the International Astronomical Union. He is the Principal Investigator of Pune Knowledge Cluster along with Professor L. S. Shashidhara.
NGC 5846 is an elliptical galaxy located in the constellation Virgo. It is located at a distance of circa 90 million light years from Earth, which, given its apparent dimensions, means that NGC 5846 is about 110,000 light years across. It was discovered by William Herschel on February 24, 1786. It lies near 110 Virginis and is part of the Herschel 400 Catalogue. It is a member of the NGC 5846 Group of galaxies, itself one of the Virgo III Groups strung out to the east of the Virgo Supercluster of galaxies.
NGC 1386 is a spiral galaxy located in the constellation Eridanus. It is located at a distance of circa 53 million light years from Earth, which, given its apparent dimensions, means that NGC 1386 is about 50,000 light years across. It is a Seyfert galaxy, the only one in Fornax Cluster.
NGC 3665 is a lenticular galaxy located in the constellation Ursa Major. It is located at a distance of circa 85 million light-years from Earth, which, given its apparent dimensions, means that NGC 3665 is about 85,000 light years across. It was discovered by William Herschel on March 23, 1789.
NGC 2273 is a barred spiral galaxy located in the constellation Lynx. It is located at a distance of circa 95 million light years from Earth, which, given its apparent dimensions, means that NGC 2273 is about 100,000 light years across. It was discovered by Nils Dunér on September 15, 1867.
NGC 4298 is a flocculent spiral galaxy located about 53 million light-years away in the constellation Coma Berenices. The galaxy was discovered by astronomer William Herschel on April 8, 1784 and is a member of the Virgo Cluster.