A5027445519- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Gamma-ray bursts and supernovae
- Stellar, planetary, and galactic studies
- Astronomical Observations and Instrumentation
- Pulsars and Gravitational Waves Research
- High-pressure geophysics and materials
- Astro and Planetary Science
- Astrophysics and Star Formation Studies
- Adaptive optics and wavefront sensing
- Galaxies: Formation, Evolution, Phenomena
- Spectroscopy and Laser Applications
- Astrophysics and Cosmic Phenomena
- Seismic Performance and Analysis
- CCD and CMOS Imaging Sensors
- Geophysics and Gravity Measurements
- Space Exploration and Technology
- X-ray Spectroscopy and Fluorescence Analysis
- Radio Astronomy Observations and Technology
- Nanowire Synthesis and Applications
- Balance, Gait, and Falls Prevention
- Planetary Science and Exploration
- Nanofabrication and Lithography Techniques
- Prosthetics and Rehabilitation Robotics
- Nuclear Physics and Applications
SRM Institute of Science and Technology
2024
Physical Research Laboratory
2015-2024
Shri Ramswaroop Memorial University
2018
STMicroelectronics (India)
2016
Leibniz Institute for Astrophysics Potsdam
2011-2012
Inter-University Centre for Astronomy and Astrophysics
2009-2011
International University of the Caribbean
2009
Abstract We present near-infrared (NIR) observations of Nova V5668 Sgr, discovered in outburst on 2015 March 15.634 ut, between 2 and 107 d after outburst. NIR spectral features are used to classify it as a Fe ii class nova. The spectra follow the evolution lines from P Cygni stage pure emission phase where shape profiles suggests presence bipolar flow. A notable feature is carbon monoxide first overtone bands which seen emission. CO modelled make estimates mass, temperature column density...
We present multi-epoch near-infrared photo-spectroscopic observations of Nova Cephei 2014 and Scorpii 2015, discovered in outburst on March 8.79 UT 2015 February 11.84 respectively. Cep shows the conventional NIR characteristics a Fe II class nova characterized by strong CI, HI O I lines, whereas Sco is shown to belong He/N with He I, OI emission lines. The highlight results consists demonstrating that symbiotic system containing giant secondary. Leaving aside T CrB recurrent novae, all...
Abstract We present 5–28 μ m SOFIA FORECAST spectroscopy complemented by panchromatic X-ray through infrared observations of the CO nova V5668 Sgr documenting formation and destruction dust during ∼500 days following outburst. Dust condensation commenced 82 after outburst at a temperature ∼1090 K. The indicates that condensate was amorphous carbon. There gradual decrease grain size mass recovery phase. Absolute parameter values given here are for an assumed distance 1.2 kpc. conclude maximum...
ABSTRACT The eruption of Nova V2891 Cygni in 2019 offers a rare opportunity to explore the shock-induced processes novae ejecta. spectral evolution shows noticeable differences various oxygen emission lines such as O i 7773 Å, 8446 1.1286 μm, 1.3164 etc. Here, we use synthesis code cloudy study temporal these lines. Our photoionization model requires introduction component with very high density ($n \sim 10^{11}$ cm$^{-3}$) and an enhanced abundance (O/H $\sim$ 28) produce Å line, suggesting...
We present multi-epoch near-infrared observations of Nova Ophiuchi 2015 which was discovered during outburst in March 2015. This nova showed a few special properties viz. (i) it displayed an unusual prolonged flat-top light curve does not easily fit into known classes curves, (ii) evidence for possessing evolved secondary the outbursting binary system, and (iii) made rare reverse hybrid transition from He/N class to Fe ii early its outburst. The studies focus on spectroscopic evolution...
We present near-infrared spectroscopy of the NGC 5128 supernova SN 2016adj in first 2 months following discovery. report detection overtone carbon monoxide emission at $\sim58.2$ d after discovery, one earliest detections CO an erupting supernova. model to derive mass, temperature and velocity, assuming both pure $^{12}$CO a composition that includes $^{13}$CO; case for latter is isotopic analyses meteoritic grains, which suggest core collapse supernovae can synthesise significant amounts...
Ultra Violet Imaging Telescope (UVIT) is one of the five payloads aboard Indian Space Research Organization (ISRO)'s ASTROSAT space mission, with broad science objectives extending from individual hot stars and star-forming regions to active galactic nuclei. The imaging performance UVIT would depend on several factors in addition optics: e.g., resolution detectors, satellite drift jitter, image frame acquisition rate, sky background, source intensity, etc. use intensified CMOS-imager–based...
The Multi-Unit Spectroscopic Explorer (MUSE), an integral-field spectrograph for the ESO Very Large Telescope, has been built and integrated by a consortium of 7 European institutes. MUSE can simultaneously record spectra across field view 1 square arcminute in wavelength range from 465nm to 930nm. calibration unit (CU) was developed provide accurate flat fielding, spectral, geometrical, image quality efficiency both wide-field AO-assisted narrow-field modes. This paper describes performance...
ABSTRACT The time-scales of variability in active M dwarfs can be related to their various physical parameters. Thus, it is important understand such decipher the physics these objects. In this study, we have performed low resolution (∼5.7 Å) spectroscopic monitoring 83 (M0–M6.5) study H α/H β emissions; over from ∼0.7 2.3 h with a cadence ∼3–10 min. Data sample another 43 late-type (M3.5–M8.5) literature are also included explore entire spectral sequence. 53 objects our (∼64 per cent) show...
ABSTRACT Mt Abu Faint Object Spectrograph and Camera (MFOSC-P) is an in-house-developed instrument for the Physical Research Laboratory (PRL) 1.2 m telescope at Abu, India, commissioned in 2019 February. Here we present first science results derived from low-resolution spectroscopy programme of a sample M dwarfs carried out during commissioning run MFOSC-P between February June. carry great significance exoplanet searches habitable zone are among promising candidates observatory’s several...
We present multi-epoch optical and near-infrared observations of the highly reddened, \pion{Fe}{ii} class slow nova V2891 Cygni. The span 15 months since its discovery. initial rapid brightening from quiescence, presence a $\sim$35 day long pre-maximum halt, is well documented. evidence that current outburst Cyg has undergone several distinct episodes mass ejection seen through time-varying P Cygni profiles O\,{\sc i} 7773\,$\AA$ line. A highlight occurrence dust formation event centred...
Near-infrared (NIR) and optical photometry spectroscopy are presented for the nova V1831 Aquilae, covering early decline dust-forming phases during first ∼90 d after its discovery. The is highly reddened due to interstellar extinction. Based solely on nature of NIR spectrum, we able classify be Fe ii class. distance extinction estimated 6.1 ± 0.5 kpc Av ∼ 9.02, respectively. Lower limits electron density, emission measure ionized ejecta mass made from a Case B analysis Brackett lines, while...
Mt. Abu Faint Object Spectrograph and Camera-Pathfinder (MFOSC-P) is an instrument currently under development for PRL 1.2m Optical-Near Infrared Telescope at Abu. It a pathfinder bigger more complex next generation on upcoming 2.5m telescope. MFOSC-P has been conceptualized as general purpose user's with sufficient ease in its operation. offers options both the imaging well spectroscopy within same optical chain visible waveband (4500-8500 angstroms). The optics designed to provide 'seeing...
Temperature plays a crucial role in deciding SRAM performance especially at very low voltage. bitcell has conflicting constraints of write-ability and stability cold (-40°C typically) hot temperature (125°C respectively. In order to reduce minimum operating voltage (VMIN), write assist schemes are deployed. Fully-Depleted SOI (FDSOI) technology offers single P-well bitcell, where can be used adjust the state body (or P-well) all devices. This vary from -1.1V +1.1V. this paper, we present...
SU Lyn, a star that ostensibly appears to be an unremarkable late M type giant, has recently been proposed symbiotic largely based on its hard X-ray properties. The does not display, in low-resolution optical spectra, the high excitation lines typically seen spectra of stars. In present work, UV, optical, and near-infrared observations are presented, aimed at exploring strengthening classification for this star. Our Far-UV 1300-1800$Å$ spectrum obtained with ASTROSAT mission's UVIT payload,...
The 24 IFU from MUSE are equipped with 4K x CCD detectors which operated at cryogenic temperature around 160 K. large size of the chip combined a rather fast camera (F/2) impose strong positioning constrains. sensitive surface should remain in an angular envelope less than 30 arc sec both directions. ambitious goal having same spectrum format on every detector imposes also very accurate image plane. central pixel has to be located square smaller 50 microns relative external references. first...
Astronomical instrumentation is most of the time faced with challenging requirements in terms sensitivity, stability, complexity, etc., and therefore leads to high performance developments that at first sight appear be suitable only for specific design application telescope. However, their usefulness other disciplines applications not excluded. The ERA2 facility a lab demonstrator, based on high-performance astronomical spectrograph, which intended explore innovation potential fiber-coupled...
For any modern astronomical observatory, it is essential to have an efficient interface between the telescope and its back-end instruments. However, for small medium-sized observatories, this requirement often limited by tight financial constraints. Therefore a simple yet versatile low-cost control system required such observatories minimize cost effort. Here we report development of modern, multipurpose instrument TELICS (Telescope Instrument Control System) integrate controls various...
Abstract We present a series of near-infrared spectra Nova Ophiuchus 2017 in the K band that record evolution first overtone CO emission unprecedented detail. Starting from 11.7 days after maximum, when is detected at great strength, track to +25.6 by which time it found have rapidly declined strength almost factor ∼35. The cause for rapid destruction examined framework different mechanisms destruction, namely, an increase photoionizating flux, chemical pathways or energetic nonthermal...
The eruption of Nova V2891 Cygni in 2019 offers a rare opportunity to explore the shock-induced processes novae ejecta. spectral evolution shows noticeable differences various oxygen emission lines such as O I 7773 {\AA}, 8446 1.1286 $\mu$m, 1.3164 etc. Here, we use synthesis code CLOUDY study temporal these lines. Our photoionization model requires introduction component with very high density ($n ~ 10^{11}$ cm$^{-3}$) and an enhanced abundance (O/H $\sim$ 28) produce {\AA} line, suggesting...