A5035626425- Gamma-ray bursts and supernovae
- Astrophysical Phenomena and Observations
- Pulsars and Gravitational Waves Research
- Stellar, planetary, and galactic studies
- Astrophysics and Cosmic Phenomena
- Astro and Planetary Science
- Neutrino Physics Research
- Atmospheric and Environmental Gas Dynamics
- Nuclear Physics and Applications
- Calibration and Measurement Techniques
- Solar and Space Plasma Dynamics
- Diabetes and associated disorders
- Liver Disease Diagnosis and Treatment
- Plant Gene Expression Analysis
- X-ray Spectroscopy and Fluorescence Analysis
- Radiation Therapy and Dosimetry
- Diabetes, Cardiovascular Risks, and Lipoproteins
- Fermentation and Sensory Analysis
- Optical Systems and Laser Technology
- Atmospheric Ozone and Climate
- High-pressure geophysics and materials
- Phytochemicals and Antioxidant Activities
- Integrated Circuits and Semiconductor Failure Analysis
- Advanced Optical Sensing Technologies
- Gaussian Processes and Bayesian Inference
Indian Institute of Astrophysics
2019-2024
Purdue University West Lafayette
2024
Pondicherry University
2022-2024
Indian Agricultural Research Institute
2024
Abstract We present early-phase panchromatic photometric and spectroscopic coverage spanning the far-ultraviolet to near-infrared regime of nearest hydrogen-rich core-collapse supernova (SN) in last 25 yr, SN 2023ixf. observe early “flash” features optical spectra due confined dense circumstellar material (CSM). high-ionization absorption lines (Fe ii , Mg ) ultraviolet from very on. also a multipeaked emission profile H α spectrum beginning at ∼16 days, which indicates ongoing interaction...
Abstract We report observations of the optical counterpart long gamma-ray burst (GRB) GRB 230812B and its associated supernova (SN) SN 2023pel. The proximity ( z = 0.36) high energy E γ ,iso ∼ 10 53 erg) make it an important event to study as a probe connection between massive star core collapse relativistic jet formation. With phenomenological power-law model for afterglow, we find late-time flattening consistent with presence SN. 2023pel has absolute peak r -band magnitude M −19.46 ± 0.18...
The third observing run by LVC has brought the discovery of many compact binary coalescences. Following detection first neutron star merger in this (LIGO/Virgo S190425z), we performed a dedicated follow-up campaign with Zwicky Transient Facility (ZTF) and Palomar Gattini-IR telescopes. initial skymap single-detector gravitational wave (GW) trigger spanned most sky observable from Observatory. Covering 8000 deg$^2$ over next two nights, corresponding to 46\% integrated probability, ZTF system...
Abstract We present the design and performance of GROWTH-India telescope, a 0.7 m robotic telescope dedicated to time-domain astronomy. The is equipped with 4k back-illuminated camera that gives 0.°82 field view sensitivity g′ ∼ 20.5 in 5 minute exposures. Custom software handles observatory operations: attaining high on-sky observing efficiencies (≳80%) allowing rapid response targets opportunity. data processing pipelines are capable performing point-spread function photometry as well...
We present a systematic search for optical counterparts to 13 gravitational wave (GW) triggers involving at least one neutron star during LIGO/Virgo's third observing run. searched binary (BNS) and black hole (NSBH) merger localizations with the Zwicky Transient Facility (ZTF) undertook follow-up Global Relay of Observatories Watching Transients Happen (GROWTH) collaboration. The GW had median localization 4480 deg^2, distance 267 Mpc false alarm rates ranging from 1.5 1e-25 per yr. ZTF...
We present optical observations and analysis of a bright type Iax SN~2020udy hosted by NGC 0812. The light curve evolution is similar to other SNe. Analytical modeling the quasi bolometric curves SN 2020udy suggests that 0.08$\pm$0.01 M$_{\odot}$ $^{56}$Ni would have been synthesized during explosion. Spectral features are members class showing weak Si {\sc II} line. late-time spectral sequence mostly dominated Iron Group Elements (IGEs) with broad emission lines. Abundance tomography time...
Abstract We present optical UBVRI photometry and low-to-medium resolution spectroscopic observations of type Iax supernova SN 2020sck spanning −5.5 days to +67 from maximum light in the B- band. From photometric analysis we find Δ m B (15) = 2.03 ± 0.05 mag M −17.81 0.22 mag. Radiation diffusion model fit quasi-bolometric curve indicates 0.13 0.02 ⊙ 56 Ni 0.34 ejecta are synthesized explosion. Comparing observed with angle-averaged bolometric a three-dimensional pure deflagration explosion...
We investigate the observational properties of a hydrogen-deficient superluminous supernova (SLSN) SN 2020ank (at z = 0.2485), with help early phase observations carried out between $-$21 and +52 d since $g$-band maximum. Photometrically, is one brightest SLSN ($M_{g,peak}$ $\sim$ $-$21.84 $\pm$ 0.10 mag), having fast pre-peak rising post-peak decaying rates. The bolometric light curve exhibits higher peak luminosity ($L_{max}$) $\sim$(3.9 0.7) $\times$ 10$^{44}$ erg s$^{-1}$ appears to be...
We present comprehensive spectroscopic and photometric analyses of the intermediate luminosity Type Iax supernova (SN Iax) 2019muj based on multi-band datasets observed through framework OISTER target-of-opportunity program. SN exhibits almost identical characteristics with subluminous SNe 2008ha 2010ae in terms spectral features light curve evolution at early phase, except for peak luminosity. The long-term observations unveil flattening curves late time as seen a luminous 2014dt. This can...
Abstract We present a self-consistent representation of the atmosphere and implement interactions light with using photon Monte Carlo approach. compile global climate distributions based on historical data, vertical profiles thermodynamic quantities, spatial models cloud variation cover, four kinds aerosols. then refraction, Rayleigh scattering, molecular interactions, Tyndall–Mie scattering to all photons emitted from astronomical sources various background components physics first...
Abstract We present optical observations and analysis of the bright type Iax supernova SN 2020udy hosted by NGC 0812. The evolution light curve is similar to that other SNe. Analytical modeling quasi-bolometric curves suggests 0.08 ± 0.01 M ⊙ 56 Ni would have been synthesized during explosion. spectral features are those members class, showing a weak Si ii line. late-time sequence mostly dominated iron group elements with broad emission lines. Abundance tomography time series using TARDIS...
Abstract High-cadence ultraviolet, optical, and near-infrared photometric low-resolution spectroscopic observations of the peculiar Type II supernova (SN) 2018hna are presented. The early-phase multiband light curves (LCs) exhibit adiabatic cooling envelope emission following shock breakout up to ∼ 14 days from explosion. SN has a rise time 88 in V band, similar 1987A. A 56 Ni mass ∼0.087 ± 0.004 M ⊙ is inferred for its bolometric LC. Hydrodynamical modeling phase suggests progenitor with...
ABSTRACT S190426c/GW190426_152155 was the first probable neutron star–black hole merger candidate detected by LIGO-Virgo Collaboration. We undertook a tiled search for optical counterparts of this event using 0.7-m GROWTH-India Telescope. Over period two weeks, we obtained multiple observations over 22.1 deg2 area, with 17.5 per cent probability containing source location. Initial efforts included obtaining photometry sources reported various groups, and visual in all galaxies contained...
We present early-phase panchromatic photometric and spectroscopic coverage spanning far-ultraviolet (FUV) to the near-infrared (NIR) regime of nearest hydrogen-rich core-collapse supernova in last 25 years, SN 2023ixf. observe early 'flash' features optical spectra due a confined dense circumstellar material (CSM). high-ionization absorption lines (FeII, MgII) ultraviolet from very on. also multi-peaked emission profile H-alpha spectrum beginning ~16 d, which indicates ongoing interaction...
Abstract We present optical, near-infrared, and radio observations of supernova (SN) SN IIb 2022crv. show that it retained a very thin H envelope transitioned from an to Ib; prominent α seen in the pre-maximum phase diminishes toward post-maximum phase, while He i lines increasing strength. SYNAPPS modeling early spectra 2022crv suggests absorption feature at 6200 Å is explained by substantial contribution together with Si ii , as also supported velocity evolution . The light-curve...
We present optical photometric and spectroscopic analysis of a Type Iax supernova (SN) 2020rea situated at the brighter luminosity end supernovae (SNe). The light curve decline rate SN~2020rea is $\Delta$m$_{15}$(g) = 1.31$\pm$0.08 mag which similar to SNe 2012Z 2005hk. Modelling pseudo bolometric with radiation diffusion model yields mass $^{56}$Ni 0.13$\pm$0.01 M$_{\odot}$ an ejecta 0.77$^{+0.11}_{-0.21}$ M$_{\odot}$. Spectral features during photospheric phase show good resemblance SN...
Background: Chronic kidney disease (CKD) results in profound lipid disorders, which stem largely from dysregulation of high-density lipoproteins (HDL) and triglyceride-rich lipoprotein metabolism. Objectives were to evaluate the correlation between chronic disease, dyslipidaemia dysglycemia. Methods: In-patient outpatient department (OPD) medicine, COM JNM Hospital, Kalyani. Cases are defined as patients (>20 years age) with a diagnosis CKD (non-oedematous). The controls age...
We present the optical (UBVRI) and ultraviolet (Swift-UVOT) photometry, spectroscopy of Type Ia supernova SN 2017hpa. study broadband UV+optical light curves low resolution spanning from $-13.8$ to $+108$~d maximum in $B$-band. The photometric analysis indicates that 2017hpa is a normal type with $\Delta m_{B}(15) = 0.98\pm0.16$ mag $M_{B}=-19.45\pm0.15$ at distance modulus $\mu 34.08\pm0.09$ mag. $(uvw1-uvv)$ colour evolution shows falls NUV-blue group. $(B-V)$ bluer comparison supernovae....
We present a self-consistent representation of the atmosphere and implement interactions light with using photon Monte Carlo approach. compile global climate distributions based on historical data, vertical profiles thermodynamic quantities, spatial models cloud variation cover, four kinds aerosols. then refraction, Rayleigh scattering, molecular interactions, Tyndall-Mie scattering to all photons emitted from astronomical sources various background components physics first principles. This...
We present a weak lensing analysis of the galaxy cluster Abell 2390 at z = 0.23 using second moment shape measurements made in 411 short 60s exposures. The exposures are obtained three broadband photometric filters (g, r, i) WIYN-ODI. Shape measurement individual is done matching algorithm. Forced used when algorithm fails to converge low signal noise ratio (SNR). images combined inverse error weight obtain accurate sources and hence recover shear. use PhoSim simulations validate shear...
We present the optical photometric and spectroscopic analysis of two type Iax SNe 2018cni 2020kyg. SN is a bright (M$_{V,peak}$ = $-$17.81$\pm$0.21 mag) whereas 2020kyg $-$14.52$\pm$0.21 faint one. derive $^{56}$Ni mass 0.07 0.002 M${_\odot}$, ejecta 0.48 0.14 M${_\odot}$ for 2020kyg, respectively. A combined study in $R/r$- band reveals that brighter objects tend to have longer rise time. However, correlation between peak luminosity decline rate shows exhibit distinct behaviour. Comparison...
Abstract We present optical observations and Monte Carlo radiative transfer modeling of the Type Ia supernova (SN Ia) SN 2011aa. With a Δ m 15 ( B ) 0.59 ± 0.07 mag peak magnitude M −19.30 0.27 mag, 2011aa has slowest decline rate among SNe Ia. The secondary maximum in I band is absent or as equally bright primary maximum. velocity C ii lower than Si . This indicates either presence at velocities line-of-sight effect. Application Arnett’s radiation diffusion model to bolometric light curve...
We present the optical photometric and spectroscopic analysis of two type Iax SNe 2018cni 2020kyg. SN is a bright (M$_{V,peak}$ = $-$17.81$\pm$0.21 mag) whereas 2020kyg $-$14.52$\pm$0.21 faint one. derive $^{56}$Ni mass 0.07 0.002 M${_\odot}$, ejecta 0.48 0.14 M${_\odot}$ for 2020kyg, respectively. A combined study in $R/r$- band reveals that brighter objects tend to have longer rise time. However, correlation between peak luminosity decline rate shows exhibit distinct behaviour. Comparison...
We present a broadband X-ray study ($\sim$\,0.3-50 keV) of the dwarf nova SS Cyg highlighting changes in accretion during two phases, quiescence and outburst states. The investigation was based on simultaneous observations carried out with XMM-Newton NuSTAR telescopes epochs, involving medium high-resolution spectroscopy. Spectra were harder ($kT_{\rm high}\sim22.8$ than high}\sim8.4$ keV), while mass rate increased by $\sim35$ times ($1.7\times10^{16} \rm g\;s^{-1}$) quiescence. bolometric...