A5017810034- Astrophysical Phenomena and Observations
- Astronomy and Astrophysical Research
- Galaxies: Formation, Evolution, Phenomena
- Stellar, planetary, and galactic studies
- Gamma-ray bursts and supernovae
- Astronomical Observations and Instrumentation
- Astrophysics and Cosmic Phenomena
- Astrophysics and Star Formation Studies
- Remote Sensing in Agriculture
- Astro and Planetary Science
- Gyrotron and Vacuum Electronics Research
- Radio Wave Propagation Studies
- Radio Astronomy Observations and Technology
- Plant Water Relations and Carbon Dynamics
- Morinda citrifolia extract uses
- SAS software applications and methods
- Dark Matter and Cosmic Phenomena
- Data Visualization and Analytics
- Adaptive optics and wavefront sensing
- Seismology and Earthquake Studies
- Radiation Therapy and Dosimetry
- Data Management and Algorithms
- Geophysics and Gravity Measurements
- Atomic and Molecular Physics
- Pulsars and Gravitational Waves Research
National Research Institute of Astronomy and Geophysics
2015-2024
Observatoire de la Côte d’Azur
2022
Samtskhe-Javakheti State University
2022
Hiroshima University
2020
Institut d'Astrophysique de Paris
2016
Sorbonne Université
2016
Centre National de la Recherche Scientifique
2016
Leibniz Institute for Astrophysics Potsdam
2011-2014
GRB 221009A is the brightest Gamma-Ray Burst (GRB) detected in more than 50 years of study. In this paper, we present observations X-ray and optical domains after obtained by GRANDMA Collaboration (which includes from 30 professional amateur telescopes) Insight-HXMT Collaboration. We study afterglow with empirical fitting GRANDMA+HXMT data, augmented data literature up to 60 days. then model numerically, using a Bayesian approach, HXMT-LE observations, that augment Swift-XRT additional...
We were able to accurately predict the shadow path and successfully observe an occultation of a bright star by Chiron on December 15, 2022. The Kottamia Astronomical Observatory in Egypt did not detect solid body, but we found three extinction features light curve that had symmetrical counterparts with respect central time occultation. One is broad shallow, whereas other two are sharper, maximum ∼25% at achieved spatial resolution 19 km per data point. From Wise Israel, detected caused main...
ABSTRACT GRB 230812B is a bright and relatively nearby (z = 0.36) long gamma-ray burst (GRB) that has generated significant interest in the community thus been observed over entire electromagnetic spectrum. We report 80 observations X-ray, ultraviolet, optical, infrared, submillimetre bands from GRANDMA (Global Rapid Advanced Network for Multimessenger Addicts) network of observatories observational partners. Adding complementary data literature, we then derive essential physical parameters...
We compile a sample of X-ray-selected galaxy groups and clusters from the XMM-Newton serendipitous source catalogue (2XMMi-DR3) with optical confirmation redshift measurement Sloan Digital Sky Survey (SDSS). The X-ray cluster candidates were selected 2XMMi-DR3 in footprint SDSS-DR7. developed finding algorithm to search for overdensities galaxies at positions photometric space measure redshifts SDSS data. detection provides 530 clusters. Of these, 310 have spectroscopic least one member...
Context. Cosmological probes based on galaxy clusters rely cluster number counts and large-scale structure information. X-ray surveys are well suited for this purpose because they far less affected by projection effects than optical surveys, properties can be predicted with good accuracy. Aims. The XMM Cluster Archive Super Survey, X-CLASS, is a serendipitous search of X-ray-detected in 4176 XMM-Newton archival observations until August 2015. All clipped to exposure times 10 20 ks obtain...
We present a catalogue of X-ray selected galaxy clusters and groups as first release the 2XMMi/SDSS Galaxy Cluster Survey. The survey is search for detected serendipitously in observations with XMM-Newton footprint Sloan Digital Sky Survey (SDSS). main aims are to identify new clusters, investigate their scaling relations, distant cluster candidates, study correlation optical properties. In this paper, we describe basic strategy characterize candidates that currently comprise 1180 objects...
Abstract We present an extensive, panchromatic photometric (UV, optical, and near-IR) low-resolution optical spectroscopic coverage of a Type IIP supernova SN 2018gj that occurred on the outskirts host galaxy NGC 6217. From V- band light curve, we estimate plateau length to be ∼ 70 ± 2 days, placing it among very few well-sampled short supernovae (SNe). With V -band peak absolute magnitude M ≤ −17.0 0.1 mag, falls in middle luminosity distribution II SNe. The color evolution is typical other...
ABSTRACT We present an extensive recent multiband optical photometric observations of the blazar S5 0716+714 carried out over 53 nights with two telescopes in India, Bulgaria, one Serbia, and Egypt during 2019 November – 2022 December. collected 1401, 689, 14726, 165 image frames B, V, R, I bands, respectively. monitored quasi-simultaneously three bands; four R; I; five B V R bands. also took 37 data only band. Single band are used to study intraday flux variability or more bands...
Based on a recent photometric redshift galaxy catalogue, we have searched for clusters in the Stripe~82 region of Sloan Digital Sky Survey by applying Adami & MAzure Cluster FInder (AMACFI). Extensive tests were made to fine-tune AMACFI parameters and make cluster detection as reliable possible. The same method was applied Millennium simulation estimate our efficiency approximate masses detected clusters. Considering all galaxies (i.e. within 1 Mpc radius which they belong with photoz...
We present a sample of 383 X-ray selected galaxy groups and clusters with spectroscopic redshift measurements (up to z ~ 0.79) from the 2XMMi/SDSS Galaxy Cluster Survey. The cluster candidates were as serendipitously detected sources 2XMMi-DR3 catalogue that located in footprint Sloan Digital Sky Survey (SDSS-DR7). galaxies available redshifts SDSS-DR10. developed an algorithm for identifying are associated spectroscopically targeted luminous red constraining redshift. A cross-correlation...
We present our discovery of dramatic variability in SDSS J1100+4421 by the high-cadence transient survey Kiso Supernova Survey (KISS). The source brightened optical at least a factor three within about half day. Spectroscopic observations suggest that this object is likely narrow-line Seyfert 1 galaxy (NLS1) z=0.840, however with unusually strong narrow emission lines. estimated black hole mass ~ 10^7 Msun implies bolometric nuclear luminosity close to Eddington limit. also extremely...
We present a galaxy cluster survey based on XMM-Newton observations that are located in Stripe 82 of the Sloan Digital Sky Survey (SDSS). The covers an area 11.25 deg$^2$. X-ray candidates were selected as serendipitously extended detected sources from third serendipitous source catalogue (3XMM-DR5). A cross-correlation candidate list comprises 94 objects with recently published and optically catalogues provided optical confirmations redshift estimates for about half sample. previously known...
We performed optical photometry and spectral observations of the symbiotic stars 4U1954+319 ZZ CMi. For 4U1954+319, using high-resolution spectra, we, measure equivalent widths diffuse interstellar bands (DIBs) estimate reddening E(B-V ) = 0:83?0:09. Using GAIA distances our photometry, we find: (1) absolute V -band magnitude MV =-5:23 ? 0:08 that mass donor is a supergiant luminosity class Ib, (2) -0:27?0:2 for CMi giant III.
The XMM-Newton Distant Cluster Project (XDCP) aims at the identification of a well defined sample X-ray selected clusters galaxies redshifts z>0.8. We present catalogue extended sources in one deepest ~250 ksec fields targeting LBQS 2215-175 covering CFHTLS deep field four. cluster is based, among others, on imaging with ESO VLT and from CFHT legacy survey. confirmation candidates done by VLT/FORS2 multi-object spectroscopy. Photometric D4 are utilized to confirm effectiveness selection...
Understanding the dynamics of galaxy triplet systems is one significant ways obtaining insight into large clusters. Towards that aim, we present a detailed study all isolated (total 315) taken from 'SDSS-based catalogue Isolated Triplets' (SIT). In addition, compared our results with those obtained for sample triplets Local Supercluster, SDSS-triplets, Tully's catalogue, Wide (W) and Compact (K)-triplets. performed correlation between dynamical parameters large-scale structure (LSS)....