A5054451841- Adaptive optics and wavefront sensing
- Distributed and Parallel Computing Systems
- Parallel Computing and Optimization Techniques
- Advanced Data Storage Technologies
- Solar Radiation and Photovoltaics
- Optical Systems and Laser Technology
- Astronomy and Astrophysical Research
- Calibration and Measurement Techniques
- Stellar, planetary, and galactic studies
- Scientific Computing and Data Management
- Optical Wireless Communication Technologies
- Optical Polarization and Ellipsometry
- Solar and Space Plasma Dynamics
- Astro and Planetary Science
- Astronomical Observations and Instrumentation
- Advanced optical system design
- Photoacoustic and Ultrasonic Imaging
- CCD and CMOS Imaging Sensors
- Cloud Computing and Resource Management
- Advanced X-ray Imaging Techniques
- Advanced Vision and Imaging
- Astrophysics and Star Formation Studies
- Interconnection Networks and Systems
- Advanced Image Processing Techniques
- Embedded Systems Design Techniques
Indian Institute of Astrophysics
2002-2024
National Institute of Technology Tiruchirappalli
2019-2020
AstraZeneca (India)
2011-2016
European Southern Observatory
2010-2015
Centre for Development of Advanced Computing
2007-2013
Pondicherry University
2013
European Southern Observatory
2010
Leiden University
2008
Leiden Observatory
2008
Udaipur Solar Observatory
2004-2007
The first transiting planetesimal orbiting a white dwarf was recently detected in K2 data of WD1145+017 and has been followed up intensively. multiple, long, variable transits suggest the objects are dust clouds, probably produced by disintegrating asteroid. In addition, system contains circumstellar gas, evident broad absorption lines, mostly u'-band, disc, indicated an infrared excess. Here we present detection change colour during transits, using simultaneous multi-band fast-photometry...
We present the results of third Optical/IR Interferometry Imaging Beauty Contest. A formal comparison is presented performance algorithms used for imaging data from optical/infrared long-baseline interferometers. The contest consists blind test sets derived model sources and distributed in OI-FITS format. consisted datasets on two objects each "observed" J, H, K bands. majority entries produced accurate reconstructions initial models. Each methods discussed.
The ESO Very Large Telescope Interferometer (VLTI) offers access to the four 8-m Unit Telescopes (UT) and 1.8-m Auxiliary (AT) of Paranal Observatory located in Atacama Desert northern Chile. two VLTI instruments, MIDI AMBER deliver regular scientific results. In parallel operation, instruments developments are pursued, new modes studied commissioned offer a wider range possibilities community increase sensitivity. New configurations ATs have been offered frequently discussed with science...
The ESO Very Large Telescope Interferometer (VLTI) offers access to the four 8-m Unit Telescopes (UT) and 1.8-m Auxiliary (AT) of Paranal Observatory located in Atacama Desert northern Chile. two VLTI instruments, MIDI AMBER deliver regular scientific results. In parallel operation, instruments developments are pursued, new modes studied commissioned offer a wider range possibilities community. New configurations ATs array discussed with science users implemented optimize return. monitoring...
We present the results of fifth Interferometric Imaging Beauty Contest. The contest consists in blind imaging test data sets derived from model sources and distributed OIFITS format. Two scenarios with CHARA/MIRC-6T were offered for reconstruction: a T Tauri disc spotted red supergiant. There eight different teams competing this time: Monnier software package MACIM; Hofmann, Schertl Weigelt IRS; Thiebaut Soulez MiRA ; Young BSMEM; Mary Vannier MIROIRS; Millour independent BSMEM entries;...
We present a formal comparison of the performance algorithms used for synthesis imaging with optical/infrared long-baseline interferometers. Five different are evaluated based on their simulated test data. Each set data is formatted in OI-FITS format. The calibrated power spectra and bispectra measured an array intended to be typical existing strengths limitations each algorithm discussed.
We present the results of fourth Optical/IR Interferometry Imaging Beauty Contest. The contest consists blind imaging test data sets derived from model sources and distributed in OI-FITS format. spectral on an object "observed" infrared with resolution. There were 4 different algorithms competing this time: BSMEM Bispectrum Maximum Entropy Method by Young, Baron & Buscher; RPR Recursive Phase Reconstruction Rengaswamy; SQUEEZE a Markov Chain Monte Carlo algorithm Baron, Monnier Kloppenborg;...
Hydrocarbon organic material, as found in the interstellar medium, exists complex mixtures of aromatic and aliphatic forms. It is considered to originate from carbon-enriched giant stars during their final stages evolution, when very strong mass loss occurs a few thousand years on way becoming planetary nebulae. We show here that same compounds appear be formed previous evolution stars, more specifically, first-ascending branch K-type stars. According our model, this happens only these are...
This paper aims at giving an update on the most versatile adaptive optics fed instrument to date, well known and successful NACO . Although is only scheduled for about two more years Very Large Telescope (VLT), it keeps evolving with additional operation modes bringing original astronomical results. The high contrast imaging community uses creatively as a test-bench SPHERE other second generation planet imagers. A new visible wavefront sensor (WFS) optimized Laser Guide Star (LGS) operations...
Process development work to provide an efficient manufacturing route a MCHr1 antagonist is presented herewith. Features of this include scalable the useful 6-oxa-2-azaspiro[3.3]heptane building block and use (soluble) alternative sodium triacetoxyborohydride.
Knowledge of the refractive index structure constant profile at an astronomical site is crucial before developing a Multi-Conjugate Adaptive Optics (MCAO) system that site. The S-DIMM+ (S-Differential Image Motion Monitor+) method proposed by Scharmer and van Werkhoven uses images recorded SHWFS (ShackHartmann Wavefront Sensor) to estimate profile. We have performed simulations same using simulated solar granulation (which are "objects") multiple layers atmosphere characterised Kolmogorov...
Abstract We report atmospheric turbulence parameters, namely seeing, tilt-anisoplanatic angle ( θ 0 ) and coherence time τ ), measured under various sky conditions, at Vainu Bappu Observatory in Kavalur. Bursts of short exposure images selected stars were recorded with a high-speed, frame-transfer CCD mounted on the Cassegrain focus newly commissioned 1.3 m telescope. The estimated median seeing is ≈ 1.85″ wavelength ∼ 600 nm, image motion correlation between different pairs 44% for 36″ mean...
Abstract We developed a tip-tilt system to compensate the turbulence induced image motion for 1.3 m telescope at Vainu Bappu Observatory, Kavalur. The instrument is designed operate visible wavelength band (480 − 700 nm) with field of view 1′ × 1′. tilt corrected images have demonstrated up ≈ 57% improvement in resolution and corresponding peak intensity increase by factor 2.8. A closed-loop correction bandwidth 26 Hz has been achieved on-sky tests root mean square star reduced ∼ 14. These...
Most of the current day grid infrastructures operate on a best effort mode, in offering services to end users. However cater ever increasing performance demands grand challenge applications, it is imperative for computing technologies evolve and mature, deliver with highest QoS attached them. The work described this paper focuses providing aware resource brokering framework that can optimal performances applications grid. Similar popular Amazon EC2 instance types classifying resources based...
Multiple Application Curvature Adaptive Optics (MACAO) systems are used at the coud´e focus of unit telescopes (UTs) La-Silla Paranal Observatory, Paranal, to correct for wave-front aberrations induced by atmosphere. These in operation since 2005 and designed provide beams with 10 mas residual rms tip-tilt error VLTI laboratory. We have initiated several technical studies such as measuring Strehl ratio images recorded guiding camera VLTI, establishing optimum setup MACAO get collimated...
This paper describes the GARUDA Access Portal (GAP) mechanism for Grid GARUDA. is India's National Computing Initiative. Users can submit jobs to through web-based Graphical User Interface provided by GAP. In this paper, authors have addressed: Architecture, different components of GAP, procedure job submission, operational challenges faced Heterogeneous Grid, and how were overcame.
The intermediate mass Herbig Ae star V1787 Ori is a member of the L1641 star-forming region in Orion A molecular cloud. We report detection an M-type companion to at projected separation 6.66" (corresponding 2577 au), from analysis VLT/NACO adaptive optics $K_s$-band image. Using astrometric data Gaia DR2, we show that and B share similar distance ($d$ $\sim$ 387 pc) proper motion, indicating they are physically associated. estimate spectral type be M5 $\pm$ 2 color--spectral calibration...
This report describes the development and scale up of synthesis oxaisoxazolidinone 1, a significant synthon in MRSA compound AZD5847. Studies were carried out to ensure short-term, risk based preparation 9 on 5 L with solid isolation procedure safe, long-term manufacturing process for both 1 through extensive hazards evaluation.