A5037218672- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Gamma-ray bursts and supernovae
- Astrophysics and Cosmic Phenomena
- Mechanics and Biomechanics Studies
- Anodic Oxide Films and Nanostructures
- Astronomical Observations and Instrumentation
- Transition Metal Oxide Nanomaterials
- High-pressure geophysics and materials
- Gas Sensing Nanomaterials and Sensors
- Advancements in Battery Materials
- Nanowire Synthesis and Applications
- Innovations in Aquaponics and Hydroponics Systems
- Electrocatalysts for Energy Conversion
- Structural Integrity and Reliability Analysis
- Conducting polymers and applications
- Particle Accelerators and Free-Electron Lasers
- IoT Networks and Protocols
- Electrochemical Analysis and Applications
- Water Quality Monitoring Technologies
- Solar and Space Plasma Dynamics
- Advanced Memory and Neural Computing
- Advanced battery technologies research
- IoT and GPS-based Vehicle Safety Systems
- Photovoltaic System Optimization Techniques
Tata Institute of Fundamental Research
2017-2025
Exponent (United States)
2022-2025
Inter-University Centre for Astronomy and Astrophysics
2017-2023
SRM Institute of Science and Technology
2022-2023
Menlo School
2022
Huntington Hospital
2005-2009
University of California System
2009
University of California, Berkeley
2005-2009
Hearst (United States)
2005-2009
Berkeley College
2007-2008
We present the first X-ray spectropolarimetric results for Cygnus X-1 in its soft state from a campaign of five IXPE observations conducted during 2023 May-June. Companion multiwavelength data are likewise shown. The 2-8 keV X-rays exhibit net polarization degree PD=1.99%+/-0.13% (68% confidence). signal is found to increase with energy across IXPE's bandpass. polarized an energy-independent angle PA=-25.7+/-1.8 deg. East North This consistent being aligned Cyg X-1's AU-scale compact radio...
Abstract We report the results of analysis an AstroSat observation black hole candidate MAXI J1535–571 during its hard-intermediate state. studied evolution spectral and timing parameters source observation. The covered a period ∼5 d consisted 66 continuous segments, corresponding to individual spacecraft orbits. Each segment was analysed independently. count rate increased roughly linearly by ∼30 per cent. modelled spectra as combination radiation from thermal disc component power law....
Abstract We present mid-infrared (MIR) spectral-timing measurements of the prototypical Galactic microquasar GRS 1915+105. The source was observed with Mid-Infrared Instrument (MIRI) onboard JWST in June 2023 at a MIR luminosity LMIR ≈ 1036 erg s−1 exceeding past IR levels by about factor 10. In contrast, X-ray flux is much fainter than historical average, source’s now–persistent ‘obscured’ state. MIRI low-resolution spectrum shows plethora emission lines, strongest which are consistent...
MAXI J1820+070 (ASSASN-18ey) is a Black hole X-ray binary discovered in 2018. The brightness of the source triggered multi-wavelength campaigns this from different observatories. We analyse Power Density Spectra obtained NICER high cadence observations hard state. obtain evolution characteristic frequencies by modelling PDS. interpret various PDS components (both QPOs and broad band noise components) as variability occurring at particular radius, explain them context Relativistic Precession...
ABSTRACT The timing properties of the Z-type low-mass X-ray binaries provide insights into emission components involved in producing unique Z-shaped track hardness–intensity diagrams these sources. In this work, we investigate AstroSat and NICER observations GX 340 + 0 covering complete ‘Z’-track from horizontal branch (HB) to extended flaring (EFB). For first time, present Z-track as seen soft X-rays using AstroSat/Soft Telescope (the colour is defined a ratio 3–6 0.5–3 keV). shape...
In this paper, a sensor-fusion based smart hydroponic system has been proposed. The aims to monitor and regulate environmental conditions boost the yield of plants grown using hydroponics. employs multiple sensors synchronized work communicate common server giving shape sensor fusion Internet Things. proposed reduces human intervention minimum, by operating autonomously. Random Forest algorithm used help identify ambient parameter be regulated on priority, thus making intelligent. By...
Abstract Cygnus X-1, the well-known accreting black hole system, exhibits several observational features hinting at an intricate interplay between accretion disk, its atmosphere known as corona, and putative relativistic jet. It has been extensively studied using all available methods, including newly technique of sensitive X-ray polarimetry. polarization characteristics are distinct for coronal jet emissions. The low measured below ∼100 keV is understood arising from corona. In contrast,...
A mechanism is proposed to describe the initiation of organized arrays nanopores and nanotubes formed via anodization titanium. The may be applicable other valve metals in addition Initiation triggered by compositional changes oxide electrolyte, near interface region, that break down planar surface. In are enhanced species (such as fluoride) form complexes with metal cations. instability driven variation oxide's composition distance from oxide/electrolyte interface. Specifically, breakdown...
We present X-ray light curves of Cygnus X-3 as measured by the recently launched AstroSat satellite. The curve folded over binary period 4.8 hours shows a remarkable stability past 45 years and we find that can use this information to measure zero point better than 100 s. revisit historical phase measurements examine years. new ephemeris with derivative determined an accuracy much previously reported. do not any evidence for second in variation. precise measurements, however, indicate hint...
Abstract Nova Her 2021 (V1674 Her), which erupted on June 12, reached naked-eye brightness and has been detected from radio to γ -rays. An extremely fast optical decline of 2 magnitudes in 1.2 days strong Ne lines imply a high-mass white dwarf. The pre-outburst detection 501.42 s oscillation suggests magnetic This is the first time that an this magnitude classical nova prior outburst. We report X-ray outburst observations Swift Chandra uniquely show (1) very modulation supersoft X-rays at...
Bulk quantities of self-assembled, functionalized nickel oxide nanowires (lengths ; mean diameter ) have been grown by a novel electrochemical method consisting multistep oxidation Ni–Cr alloys in high-temperature, pressurized water. Nanowires form when growth results deficit the electrolyte ahead growing NiO. The compositional gradient breaks up planar NiO/water interface into cellular interface, resulting NiO nanowires.
In a series of two papers, mechanism is proposed to describe the initiation organized arrays nanopores and nanotubes formed via anodization titanium. Part I describes initiation, based on instability planar oxide/electrolyte interface, develops criterion for nanopores, while present paper uses this interface calculate size/spacing nanopores. To facilitate calculation, destabilized modeled by sine waves, representing surface perturbations. Because growth rates waves are function their...
Accreting X-ray pulsars (XRPs) undergo luminous outbursts during which the luminosity-dependent spectral and timing features of neutron star's emission can be analyzed in detail, thus shedding light on accretion regime at work. We took advantage a monitoring campaign performed with NuSTAR, Swift/XRT, AstroSat NICER, to follow Be/X-ray Binary 2S 1553-542 along one its rare trace evolution. report discovery cyclotron line energy for first time this source. The pulse profiles pulsed fraction...
Views Icon Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Twitter Facebook Reddit LinkedIn Tools Reprints and Permissions Cite Search Site Citation C. Bharatiraja, Prithvi Krishna Chittoor, Yash Vardhan Bhargava; An IoT based centralized smart locker using RFID technology. AIP Conf. Proc. 27 February 2023; 2427 (1): 020098. https://doi.org/10.1063/5.0101139 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote...
Abstract We conduct a spectropolarimetric study of the accreting X-ray pulsar Hercules X-1 using observations with Imaging Polarimetry Explorer (IXPE). IXPE monitored source in three different epochs, sampling two “Main-on” and one “Short-on” state well-known super-orbital period source. find that 2–7 keV polarization fraction increases significantly from ∼7% to 9% Main-on ∼15%–19% Short-on state, while angle remains more or less constant changes slightly, ∼47°–59°, all epochs. The degree...
We analyse the aperiodic flaring features, also known as shots, observed in Cyg X-1 0.1-80 keV energy band using a 6.39 ks simultaneous observation with AstroSat and NICER. detect 49 shots soft hard X-ray bands NICER AstroSat-LAXPC, respectively. observe shot profile for first time X-rays (0.1-3 keV), which shows spectral peak at $\sim$2 keV. Using time-averaged spectroscopy, we measured truncation of inner accretion disk $6.7\pm0.2$ gravitational radii. The shot-phase resolved spectroscopy...
Cygnus X-1, the well-known accreting black hole system, exhibits several observational features hinting at an intricate interplay between accretion disk, its atmosphere known as corona and putative relativistic jet. It has been extensively studied using all available methods, including newly technique of sensitive X-ray polarimetry. polarization characteristics are distinct for coronal jet emissions. The low measured below $\sim$100 keV is understood arising from corona. In contrast, high...
4U 1543-47 underwent its brightest outburst in 2021 after two decades of inactivity. During decay phase, AstroSat conducted nine observations the source spanning from July $1^{st}$ to September $26^{th}$, 2021. The first three were performed with an offset 40 arcmin AstroSat/LAXPC, while remaining six on-axis observations. In this report, we present a comprehensive spectral analysis as it was High/Soft state during entire observation period. exhibited disk-dominated spectra weak high-energy...
Abstract Understanding the spectral evolution along “Z”-shaped track in hardness–intensity diagram of Z sources, which are a class luminous neutron star low-mass X-ray binaries, is crucial to probe accretion processes close star. Here, we study horizontal branch (HB) and normal (NB) source GX 340+0 using AstroSat data. We find that HB NB appear as two different types intensity dips, can any sequence with various depths. Our 0.8–25 keV spectra dips hard apex be modeled by emissions from an...
Nickel oxide (NiO) nanowires were used as electrodes in lithium batteries for capacity assessments. The grown directly on Alloy 600 foil (16 Cr- 8Fe - bal Ni) that serves the current collector. are synthesized by a novel electrochemical process. technique grows self-assembled, high quality, density nickel-rich with an average diameter of 25nm and aspect ratios between 400:1 600:1. Preliminary testing indicates battery is stable constant capacities from third cycle onward. addition sputtered...
Agriculture has proven to be an integral part of human history and evolution. Traditionally, farming been a tiresome task. It demands excessive physical effort knowledge geographical factors. Apart from this, the yield conventional method is prone dangers such as insect attacks, rotting, exposure unfavorable environmental conditions. Hydroponic IoT can prove effective solution above shortcomings. In this article, smart, self-monitoring, regulatory system have proposed. devised monitor...