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PHYSICAL RESEARCH LABORATORY, AHMEDABAD
Astronomy & Astrophysics Division (A&A)

IR Telescope in Mt. Abu
A&A Faculty Staff Students/PDFs Publications Seminar Annual Report Events


Chair: Prof. K. S. Baliyan

Overview

The Research in the Astronomy and Astrophysics Division involves investigations in the optical, infrared, X-ray and the radio wavelength bands to understand some of the outstanding problems related to galactic and extragalactic cosmic phenomena, such as star formation, stellar evolution, interstellar medium, binary stars, pulsars, active galactic nuclei and giant radio galaxies. Solar activity and its impact on space weather are also being studied using radio techniques.

Research Programmes

The research activities in Optical and Infrared Astronomy optimally blend the capability of a moderately sized telescope (1.2m) with state-of-the-art instruments. Some of the key research areas include,

  1. Infrared photometric and spectroscopic studies on Novae and Nova-like Stellar Phenomena,
  2. Infrared photometric imaging studies of Massive Star Forming Regions in our galaxy for investigating the star formation processes,
  3. Monitoring of short time (hour-day) variability of Active Galactic Nuclei.
  4. High angular resolution (milli-arcsec) studies (in the infrared bands) of the atmospheres of Cool Giant Stars to resolve the structure of Dust Shells,
  5. Spatio-kinematic studies of Planetary Nebulae of different morphologies,
  6. Infrared surface photometric studies on Starburst Galaxies to understand the causes of high rate of star formation, and
  7. Detection of extrasolar planetary systems.

    List of Publications (in Refereed Journals) Using Data from Mt. Abu Telescope.

The programmes of the radio astronomy group include

  1. Space Weather investigations involving Interplanetary Scintillations, Solar Flare activity and Coronal Mass Ejections; and Studies on Pulsar bursting phenomena.
  2. Investigationof Solar atmospheric (coronal) differential rotation to examine possible connections with photo-spheric differential rotation,
  3. Investigation of high-z Quasars and Giant Radio Galaxies for understanding the morphologies of these objects and the nature of the Inter-Galactic Medium,


The programmes of the X-ray astronomy group include
  1. Temporal and spectral studies of X-ray binaries such as accretion powered X-ray pulsars, black hole candidates etc.
  2. X-ray and Infrared studies of Be/X-ray binary pulsars
  3. Studies of high resolution X-ray spectra of solar flares in the energy range 4-20 keV observed by SOXS low energy detector payload of PRL onboard GSAT-2

Facilities

The Division operates the Mt. Abu Observatory with the 1.2m Infrared Telescope having the back-end instruments, NICMOS Infrared Camera and Spectrograph, Imaging Fabry-Perot Spectrometer, high time resolution Infrared Photometer, Optical Polarimeter and Fibre-linked Grating Spectrograph. Occasionally, collaborative observations are being made using larger telescopes at national and international observatories at Hanle, Hawaii, La Palma, South Africa and Chile. Telescopes in space like Spitzer IR telescope are also used for observations. The Radio Astronomy programmes utilize the national facility Giant Metre Wave Radio Telescope and Ooty Radio Telescope of TIFR. A new high resolution optical spectrometer is being built for detecting extrasolar planets by the radial velocity technique.

Ph.D. Courses Offered

Astronomy & Astrophysics
Radio Astronomy
Solar Physics and Space Weather
Astronomical Instrumentation and Data Processing Techniques

Select List of Recent Publications

Sunil Chandra, Kiran S. Baliyan, Shashikiran Ganesh and Umesh C. Joshi : Optical Polarimetry of the blazar CGRaBS J0211+1051 from Mount Abu Infrared Observatory, The Astrophysical Journal, 746, 92 (2012)

Sachindra Naik, Biswajit Paul, Zulfikar Ali : X-ray Spectroscopy of High Mass X-ray Binary Pulsar Centaurus X-3 Over its Binary Orbit, The Astrophysical Journal, 737, 79 (2011)

Ashok K. Singal : Large Peculiar Motion of the Solar System from the Dipole Anisotropy in Sky Brightness due to Distant Radio Sources, Astrophysical Journal Letters, 742, L23 (2011)

Biswajit Paul and Sachindra Naik: Transient High Mass X-ray Binaries, Bull. Astr. Sco. India, 39, 429 (2011) (An Invited Review)

Tapas Baug, T. Chandrasekhar : Near-infrared angular diameters of a few asymptotic giant branch variables by lunar occultations, Monthly Notices of the Royal Astronomical Society, 419, 866 (2011)

P. Janardhan, S. K. Bisoi, S. Ananthakrishnan,M. Tokumaru, and K. Fujiki : The prelude to the deep minimum between solar cycles 23 and 24: Interplanetary scintillation signatures in the inner heliosphere, Geophys. Res. Lett., 38, L20108 (2011)

Rajmal Jain, Arun K. Awasthi, Babita Chandel, Lokesh Bharti, Y. Hanaoka and A. L. Kiplinger : Probing the role of magnetic-field variations in NOAA AR 8038 in producing a solar flare and CME on 12 May 1997, Solar Physics, 271, 57 (2011)

K. P. Raju, T. Chandrasekhar, N. M. Ashok : Analysis of coronal green line profiles: Evidence of excess blueshifts, The Astrophysical Journal, 736, 164 (2011)

Sachindra Naik, Biswajit Paul, Chetan Kachhara, Santosh V. Vadawale : Suzaku Observation of the Transient X-ray Pulsar GRO J1008-57, Monthly Notices of the Royal Astronomical Society, 413, 241 (2011)

Satish Chandra, Hari Om Vats : Periodicities in the coronal rotation and sunspot numbers, Monthly Notices of the Royal Astronomical Society, 414, 3158 (2011)

L. K. Dewangan, B. G. Anandarao : Infrared photometric study of the massive star-forming region S235 using Spitzer-Infrared Array Camera and JHK observations, Monthly Notices of the Royal Astronomical Society, 414, 1526 (2011)

Sunil Chandra, K. S. Baliyan, S. Ganesh, U. C. Joshi : Rapid Optical Variability in Blazar S5 0716+71 during 2010 March, The Astrophysical Journal, 731, 118 (2011)

Hari Om Vats, Satish Chandra : North-south asymmetry in the solar coronal rotation, Monthly Notices of the Royal Astronomical Society, 413, L29 (2011)

R. G. Rastogi, P. Janardhan, K. Ahmed, A. C. Das, Susanta K. Bisoi : Unique observations of a geomagnetic SI+ ‑ SI‑ pair: Solar sources and associated solar wind fluctuations, Journal of Geophysical Research, 115, 12110 (2010)

D. P. K. Banerjee, R. K. Das, N. M. Ashok, M. T. Rushton, S. P. S. Eyres, M. P. Maxwell, H. L. Worters, A. Evans, B. E. Schaefer : Near-infrared studies of the 2010 outburst of the recurrent nova U Scorpii, Monthly Notices of the Royal Astronomical Society, 408, L71 (2010)

Bindu Rani, Alok C. Gupta, U. C. Joshi, S. Ganesh, Paul J. Wiita : Quasi-periodic Oscillations of ~15 Minutes in the Optical Light Curve of the BL Lac S5 0716+714, ApJL, 719, 153 (2010)

Sachindra Naik, D. P. K. Banerjee, N. M. Ashok, R. K. Das : Near-infrared observations of nova V574 Puppis, Monthly Notices of the Royal Astronomical Society, 404, 367 (2010)

Ashok K. Singal : Maximum Brightness Temperature of an Incoherent Synchrotron Source : Inverse Compton Limit — A Misnomer, Astrophysical Journal Letters, 703, L109-L112 (2009)

P. Janardhan, K. Fujiki, H. S. Sawant, M. Kojima, K. Hakamada, and R. Krishnan : Source regions of solar wind disappearance events, Journal of Geophysical Research, 113, A03102 (2008)

D. P. K. Banerjee, K. A. Misselt, K. Y. L. Su, N. M. Ashok, and P. S. Smith : Spitzer observations of V4332 Sagittarii: Detection of Alumina Dust, Astrophysical Journal Letters, 666, L25-L28 (2007)